阅读说明：本技术 一种太赫兹辐射体散射修正因子的测量系统及方法 (System and method for measuring scattering correction factor of terahertz radiator ) 是由 程春悦 李芳� 曹月 孙晓宁 于 2020-05-20 设计创作，主要内容包括：本发明涉及测量技术领域,尤其涉及一种太赫兹辐射体散射修正因子的测量系统及方法。发射信号经网络分析仪发射模块发出后经过反射镜的反射后到达大口径极化栅网,大口径极化栅网将来自反射镜的发射信号电磁波反射至第二极化栅网,经被测辐射体或参考测试平板反射回来的信号通过第二极化栅网,通过第二极化栅网的信号入射到大口径极化栅网；基于电磁波极化分离原理,发射模块设置在靠近所述弓形滑轨的下端的位置,接收模块设置在所述弓形滑轨上,即将发射天线放置在弓形滑轨之外,通过大口径极化栅网和另一个极化栅网实现入射电磁波的馈入,发射天线在物理结构上完全不遮挡接收天线,实现包括死区在内的整个散射修正因子测量问题。(The invention relates to the technical field of measurement, in particular to a system and a method for measuring a terahertz radiator scattering correction factor. The transmission signal is transmitted by a network analyzer transmission module, reflected by a reflector and then reaches the large-aperture polarization grid mesh, the large-aperture polarization grid mesh reflects the transmission signal electromagnetic wave from the reflector to a second polarization grid mesh, the signal reflected by a measured radiator or a reference test panel passes through the second polarization grid mesh, and the signal passing through the second polarization grid mesh is incident to the large-aperture polarization grid mesh; based on the principle of electromagnetic wave polarization separation, the transmitting module is arranged at a position close to the lower end of the arched slide rail, the receiving module is arranged on the arched slide rail, namely, the transmitting antenna is arranged outside the arched slide rail, the feeding-in of incident electromagnetic waves is realized through the large-caliber polarization grid mesh and the other polarization grid mesh, the transmitting antenna does not shield the receiving antenna completely on the physical structure, and the problem of measuring the whole scattering correction factor including dead zones is solved.)

1. A measurement system for terahertz radiation body scattering correction factor, its characterized in that: the device comprises a network analyzer, a transmitting module, a receiving module, a reflector, a large-caliber polarization grid mesh, a second polarization grid mesh, a measured radiator, a reference test flat plate and an arched slide rail;

one side of the arch opening of the arch-shaped slide rail faces to a tested object area, one side of the arch-shaped slide rail, which is far away from the arch opening, is provided with a network analyzer, the tested object area is provided with a tested radiator or a reference test flat plate, the transmitting module is arranged at a position close to the lower end of the arch-shaped slide rail, and the receiving module is arranged on the arch-shaped slide rail; one end of the transmitting module is connected with the network analyzer, and the other end of the transmitting module faces the reflector; the large-caliber polarization grid mesh is arranged between the arched sliding rail and a measured object of the measured object area, and the second polarization grid mesh is arranged between the large-caliber polarization grid mesh and the measured object of the measured object area; the reflector is positioned below the large-aperture polarization grid mesh to reflect the emission signal sent by the emission module to the large-aperture polarization grid mesh, and the large-aperture polarization grid mesh reflects the electromagnetic wave of the emission signal from the reflector 7 to the second polarization grid mesh.

2. The system for measuring a scattering correction factor of a terahertz radiator according to claim 1, wherein: the transmitting module comprises a transmitting spread spectrum unit and a transmitting antenna, the transmitting antenna is connected with the network analyzer through the transmitting spread spectrum unit, and the reference test flat plate is the reference metal flat plate.

3. The system for measuring a scattering correction factor of a terahertz radiator according to claim 2, wherein: the receiving module comprises a receiving spread spectrum unit and a receiving antenna, the receiving antenna is connected with the network analyzer through the receiving spread spectrum unit, and a flexible long cable is connected between the receiving spread spectrum unit and the network analyzer; the reflector is arranged on one side, far away from the transmitting module, of the reflector, and the electromagnetic waves reflected by the second polarization grid mesh are partially absorbed by the clutter absorbing material.

4. The system for measuring a scattering correction factor of a terahertz radiator according to claim 3, wherein: the test reference surface of a tested radiator or a reference test flat plate of the tested object area is a vertical surface; the receiving spread spectrum unit and the receiving antenna are arranged in the normal direction of the test datum plane, and the center of the tested radiator or the reference test flat plate is positioned on the circle center of the arched slide rail; the included angle between the large-caliber polarization grid mesh and the normal line of the test reference surface is 45 degrees, the large-caliber polarization grid mesh comprises a group of parallel metal wires, the direction of the metal wires is perpendicular to the paper surface, and one end surface of each metal wire is parallel to the second polarization grid mesh.

5. The system for measuring a scattering correction factor of a terahertz radiator according to claim 4, wherein: the second polarization grid net is parallel with the test reference surface, the second polarization grid net includes a set of parallel wire, the wire grid direction of second polarization grid net with heavy-calibre polarization grid net contained angle is 45 degrees, the aperture area of second polarization grid net is greater than surveyed irradiator or the reference test flat board of measurand area, and the signal that reflects back through surveying irradiator or reference test flat board can pass through second polarization grid net.

6. A method for measuring a scattering correction factor of a terahertz radiator is characterized by comprising the following steps: the method comprises the following steps:

p1, vertically placing a reference metal flat plate on a displacement table of the measured object area;

p2, placing the receiving spread spectrum unit and the receiving antenna of the network analyzer in the normal direction of the reference metal flat plate, wherein the center of the reference metal flat plate is positioned on the center of the arc slide rail; setting the included angle between the normal of the large-caliber polarization grid mesh and the reference metal flat plate to be 45 degrees, and setting the included angle between the wire grid direction of the second polarization grid mesh and the large-caliber polarization grid mesh to be 45 degrees;

p3, operating the network analyzer at S₂₁The mode is that the transmission signal is transmitted by the transmission frequency spreading unit of the network analyzer and the transmission antenna, reflected by the reflector and reaches the large-aperture polarization grid mesh, the large-aperture polarization grid mesh reflects the transmission signal electromagnetic wave from the reflector to the second polarization grid mesh, the signal reflected by the metal reference plate passes through the second polarization grid mesh, and the signal passing through the second polarization grid mesh enters the large-aperture polarization grid meshA radially polarized grid mesh;

p4, recording the reading of the network analyzer at the moment as S₂₁_Metal(θ₀)，S₂₁_Metal(θ₀) Taking the linear value, θ₀At this time, the angle is 0 degree, and the axis of the receiving antenna is superposed with the normal of the reference metal flat plate;

p5, changing the position of the receiving antenna clockwise along the arc slide rail to make the included angle between the axis of the receiving antenna and the normal of the reference metal flat plate be delta theta, and recording the reading of the network analyzer at the moment as S₂₁- "Metal (Δ θ); continuing to move the receiving antenna to the nth position along the arc-shaped sliding rail, and recording the reading of the network analyzer at the moment as S₂₁"Metal (n Δ θ), for S₂₁Summing to obtain a process parameter a₁；

P6, rotating the reference metal plate 90 degrees along the axis, repeating the steps P2-P5, and obtaining S₂₁Summing to obtain a process parameter a₂；

P7, replacing the reference metal flat plate with a measured radiator, placing the receiving spread spectrum unit and the receiving antenna of the network analyzer in the normal direction of the measured radiator, and positioning the center of the plane formed by the tip of the measured radiator on the center of the circle of the arched slide rail;

p8, operating the network analyzer at S₂₁The mode is that a transmitting signal is transmitted by a network analyzer transmitting spread spectrum unit and a transmitting antenna, then reflected by a reflector and reaches a large-aperture polarization grid mesh, the large-aperture polarization grid mesh reflects electromagnetic waves from the reflector to a second polarization grid mesh, the signal reflected by a detected radiator passes through the second polarization grid mesh, and the signal passing through the second polarization grid mesh is incident to the large-aperture polarization grid mesh;

p9, recording the reading of the network analyzer at the moment as S₂₁_BB(θ₀)，S₂₁_BB(θ₀) Taking the linear value, θ₀At the moment, the angle is 0 degree, namely the axis of the receiving antenna is superposed with the normal of the detected radiator;

p10, changing the position of the receiving antenna along the arc slide rail in the clockwise direction to make the included angle between the axis of the receiving antenna and the normal of the measured radiator be delta theta, and recording the reading of the network analyzer at the moment as S₂₁_BB(θ₀) (ii) a Continuing to move the receiving antenna 5 to the nth position along the arc-shaped sliding rail, and recording the reading of the network analyzer at the moment as S₂₁BB (n × Δ θ), the process parameter b is obtained by summing the above S21₁；

P11, rotating the detected radiator by 90 degrees along the axis, repeating the steps P8-P10, and summing S21 obtained in the process to obtain a process parameter b₂；

P12, the calculation method of the scattering correction factor S of the measured radiator is shown in formula five:

S＝(b₁*b₂)/(a₁*a₂)。

7. the method of measuring a scattering correction factor of a terahertz radiator according to claim 6, wherein:

the area of the reference metal flat plate is equivalent to that of the detected radiator; the transmitting antenna is a linear polarization antenna, and the polarization attitude is vertical polarization.

8. The method of measuring a scattering correction factor of a terahertz radiator according to claim 6, wherein:

the large-caliber polarization grid mesh comprises a group of parallel metal wires, the direction of the metal wires is vertical to the paper surface, and one end surface of each metal wire is parallel to the second polarization grid mesh; the second polarization grid mesh comprises a group of parallel metal wires, the wire grid direction of the second polarization grid mesh and the included angle of the large-caliber polarization grid mesh are 45 degrees, and the caliber area of the second polarization grid mesh is larger than a measured radiator or a reference metal flat plate of the measured object area.

9. The method of measuring a scattering correction factor of a terahertz radiator according to claim 6, wherein:

in the step P3, one half of the signals from the large-aperture polarization grid are incident to the reference metal flat plate through the polarization grid, and the other half of the signals are reflected back by the polarization grid; one part of the signal reflected by the polarized grid mesh is absorbed by the clutter absorption material, and the other part of the signal is received by the receiving antenna; the part of the signal reflected by the polarized grid network and received by the receiving antenna is identified and eliminated by the time domain gate technology of the network analyzer; the polarization attitude of the receiving antenna is horizontal polarization, namely the direction is parallel to the paper surface;

in the step P8, one half of the signals from the large-aperture polarized grid mesh are incident to the radiator to be tested through the polarized grid mesh, and the other half of the signals are reflected back by the polarized grid mesh; one part of the signal reflected by the polarized grid mesh is absorbed by the clutter absorption material, and the other part of the signal is received by the receiving antenna; the part of the signal reflected by the polarized grid network and received by the receiving antenna is identified and eliminated by the time domain gate technology of the network analyzer; the polarization attitude of the receiving antenna is horizontal polarization, i.e. the direction is parallel to the paper.

10. The method of measuring a scattering correction factor of a terahertz radiator according to claim 6, wherein:

in step P5, the angle Delta theta is 0.5-1 DEG, the axis of the receiving antenna is kept pointing to the center of the reference metal flat plate, and the reading of the network analyzer at the moment is recorded as S₂₁"Metal (Δ θ), defining the angle at this time as positive; when the receiving antenna is continuously moved to the nth position along the arched slide rail, the included angle between the axis of the receiving antenna and the normal of the reference metal flat plate is n x delta theta, and when the included angle between the axis direction of the receiving antenna and the normal direction of the reference metal flat plate is more than 40 degrees, the clockwise movement of the position of the receiving antenna is stopped, and the S position is aligned to the S position₂₁Summing to obtain a process parameter a₁As shown in formula one:

a₁(Metal)＝S₂₁_Metal(θ₀)+S₂₁_Metal(Δθ)+…+S₂₁_Metal(n*Δθ)

in step P6, pair S₂₁Summing to obtain a process parameter a₂As shown in formula two:

a₂(Metal)＝S₂₁_Metal(θ₀)+S₂₁_Metal(Δθ)+…+S₂₁_Metal(n*Δθ)

in step P10, the angle delta theta is 0.5-1 DEG, and the axis of the receiving antenna is kept pointing to the radiation to be measuredThe center of the body records the reading of the network analyzer at the moment as S₂₁_BB(θ₀) (ii) a When the receiving antenna is continuously moved to the nth position along the arch-shaped slide rail, the included angle between the axis of the receiving antenna and the normal of the measured radiator is n x delta theta, and when the included angle between the axis direction of the receiving antenna and the normal direction of the measured radiator is more than 40 degrees, the clockwise movement of the position of the receiving antenna is stopped, and the S is corrected₂₁Summing to obtain a process parameter b₁As shown in formula three:

b₁(BB)＝S₂₁_BB(θ₀)+S₂₁_BB(Δθ)+…+S₂₁_BB(n*Δθ)

in step P11, pair S₂₁Summing to obtain a process parameter b₂As shown in formula four:

b₂(BB)＝S₂₁_BB(θ₀)+S₂₁_BB(Δθ)+…+S₂₁_BB(n*Δθ)。

Technical Field

The invention relates to the technical field of measurement, in particular to a system and a method for measuring a terahertz radiator scattering correction factor.

Background

Currently, radiometers are high sensitivity receivers that receive natural radiation from objects. The radiator is used for simulating the thermal radiation of a natural object so as to calibrate the radiometer, and the emissivity of the radiator is a parameter required to be accurately obtained.

Typically, the full radiator emissivity consists of the normal emissivity (perpendicular radiator surface direction) and the scattering correction factor. As shown in fig. 1, the conventional scattering factor measurement method adopts a radar-like scattering cross section measurement mode, that is, a transmitting antenna 3 and a receiving antenna 5 are both disposed on an arcuate slide rail, the transmitting antenna generally resides in the normal direction of a measured radiator 10, and the receiving antenna moves along the arcuate slide rail. The biggest drawback of this approach is that the transmitting antenna (including the transmitting module) and the receiving antenna (including the receiving module) have certain physical dimensions, and if they are placed on the arcuate slide rail 14, there must be mutual interference or mutual shielding, that is, there are "dead corners or dead zones" in the area near the normal. In a dead angle, a receiving antenna cannot be placed due to interference, or a transmitting antenna is shielded by the receiving antenna, so that a large test error is caused, that is, the dead angle area network analyzer 1 cannot obtain measurement data or cannot obtain accurate measurement data. Typically, the dead angle region does not exceed plus or minus 10 degrees and the entire scatter correction factor measurement range does not exceed plus or minus 40 degrees.

Therefore, in response to the above problems, there is a need to solve the overall scatter correction factor measurement problem, including dead zones.

Disclosure of Invention

The invention aims to provide a system and a method for measuring a terahertz radiator scattering correction factor, which solve the problems that the whole scattering correction factor including a dead zone cannot be measured and the measurement is inaccurate due to shielding interference of a transmitting antenna and a receiving antenna on a physical structure.

In order to achieve the above purpose, the invention provides the following technical scheme:

the invention provides a system for measuring a terahertz radiator scattering correction factor, which comprises a network analyzer, an emission module, a receiving module, a reflector, a large-caliber polarization grid mesh, a second polarization grid mesh, a measured radiator, a reference test flat plate and an arched slide rail, wherein the emission module is arranged on the top of the network analyzer;

one side of the arch opening of the arch-shaped slide rail faces to a tested object area, one side of the arch-shaped slide rail, which is far away from the arch opening, is provided with a network analyzer, the tested object area is provided with a tested radiator or a reference test flat plate, the transmitting module is arranged at a position close to the lower end of the arch-shaped slide rail, and the receiving module is arranged on the arch-shaped slide rail; one end of the transmitting module is connected with the network analyzer, and the other end of the transmitting module faces the reflector; the large-caliber polarization grid mesh is arranged between the arched sliding rail and a measured object of the measured object area, and the second polarization grid mesh is arranged between the large-caliber polarization grid mesh and the measured object of the measured object area; the reflector is positioned below the large-aperture polarization grid mesh to reflect the emission signal sent by the emission module to the large-aperture polarization grid mesh, and the large-aperture polarization grid mesh reflects the electromagnetic wave of the emission signal from the reflector 7 to the second polarization grid mesh.

The transmitting module comprises a transmitting spread spectrum unit and a transmitting antenna, the transmitting antenna is connected with the network analyzer through the transmitting spread spectrum unit, and the reference test flat plate is the reference metal flat plate.

The receiving module comprises a receiving spread spectrum unit and a receiving antenna, the receiving antenna is connected with the network analyzer through the receiving spread spectrum unit, and a flexible long cable is connected between the receiving spread spectrum unit and the network analyzer; the reflector is arranged on one side, far away from the transmitting module, of the reflector, and the electromagnetic waves reflected by the second polarization grid mesh are partially absorbed by the clutter absorbing material.

The test reference surface of a tested radiator or a reference test flat plate of the tested object area is a vertical surface; the receiving spread spectrum unit and the receiving antenna are arranged in the normal direction of the test datum plane, and the center of the tested radiator or the reference test flat plate is positioned on the circle center of the arched slide rail; the included angle between the large-caliber polarization grid mesh and the normal line of the test reference surface is 45 degrees, the large-caliber polarization grid mesh comprises a group of parallel metal wires, the direction of the metal wires is perpendicular to the paper surface, and one end surface of each metal wire is parallel to the second polarization grid mesh.

Wherein, the second polarization grid net is parallel with the test reference surface, the second polarization grid net includes a set of parallel wire, the wire grid direction of second polarization grid net with heavy-calibre polarization grid net contained angle is 45 degrees, the aperture area of second polarization grid net is greater than surveyed irradiator or the reference test flat board of measurand district, and the signal that reflects back through surveying irradiator or reference test flat board can pass through second polarization grid net.

The invention also provides a method for measuring the scattering correction factor of the terahertz radiator, which comprises the following steps:

p1, vertically placing a reference metal flat plate on a displacement table of the measured object area;

p2, placing the receiving spread spectrum unit and the receiving antenna of the network analyzer in the normal direction of the reference metal flat plate, wherein the center of the reference metal flat plate is positioned on the center of the arc slide rail; setting the included angle between the normal of the large-caliber polarization grid mesh and the reference metal flat plate to be 45 degrees, and setting the included angle between the wire grid direction of the second polarization grid mesh and the large-caliber polarization grid mesh to be 45 degrees;

p3, operating the network analyzer at S₂₁The mode is that a transmission signal is transmitted by a network analyzer transmission spread spectrum unit and a transmission antenna, then reflected by a reflector and reaches a large-aperture polarization grid mesh, the large-aperture polarization grid mesh reflects the transmission signal electromagnetic wave from the reflector to a second polarization grid mesh, the signal reflected by a metal reference plate passes through the second polarization grid mesh, and the signal passing through the second polarization grid mesh is incident to the large-aperture polarization grid mesh;

p4, recording the reading of the network analyzer at the moment as S₂₁_Metal(θ₀)，S₂₁_Metal(θ₀) Taking the linear value, θ₀At this time, the angle is 0 degree, and the axis of the receiving antenna is superposed with the normal of the reference metal flat plate;

p5, changing the position of the receiving antenna clockwise along the arc slide rail to make the included angle between the axis of the receiving antenna and the normal of the reference metal flat plate be delta theta, and recording the reading of the network analyzer at the moment as S₂₁- "Metal (Δ θ); relay (S)Moving the receiving antenna to the nth position along the arc-shaped sliding rail, and recording the reading of the network analyzer at the moment as S₂₁"Metal (n Δ θ), for S₂₁Summing to obtain a process parameter a₁；

P6, rotating the reference metal plate 90 degrees along the axis, repeating the steps P2-P5, and obtaining S₂₁Summing to obtain a process parameter a₂；

P7, replacing the reference metal flat plate with a measured radiator, placing the receiving spread spectrum unit and the receiving antenna of the network analyzer in the normal direction of the measured radiator, and positioning the center of the plane formed by the tip of the measured radiator on the center of the circle of the arched slide rail;

p8, operating the network analyzer at S₂₁The mode is that a transmitting signal is transmitted by a network analyzer transmitting spread spectrum unit and a transmitting antenna, then reflected by a reflector and reaches a large-aperture polarization grid mesh, the large-aperture polarization grid mesh reflects electromagnetic waves from the reflector to a second polarization grid mesh, the signal reflected by a detected radiator passes through the second polarization grid mesh, and the signal passing through the second polarization grid mesh is incident to the large-aperture polarization grid mesh;

p9, recording the reading of the network analyzer at the moment as S₂₁_BB(θ₀)，S₂₁_BB(θ₀) Taking the linear value, θ₀At the moment, the angle is 0 degree, namely the axis of the receiving antenna is superposed with the normal of the detected radiator;

p10, changing the position of the receiving antenna along the arc slide rail in the clockwise direction to make the included angle between the axis of the receiving antenna and the normal of the measured radiator be delta theta, and recording the reading of the network analyzer at the moment as S₂₁_BB(θ₀) (ii) a Continuing to move the receiving antenna 5 to the nth position along the arc-shaped sliding rail, and recording the reading of the network analyzer at the moment as S₂₁BB (n × Δ θ), the process parameter b is obtained by summing the above S21₁；

P11, rotating the detected radiator by 90 degrees along the axis, repeating the steps P8-P10, and summing S21 obtained in the process to obtain a process parameter b₂；

P12, the calculation method of the scattering correction factor S of the measured radiator is shown in formula five:

S＝(b₁*b₂)/(a₁*a₂)。

the area of the reference metal flat plate is equivalent to that of the detected radiator; the transmitting antenna is a linear polarization antenna, and the polarization attitude is vertical polarization.

The large-caliber polarization grid mesh comprises a group of parallel metal wires, the direction of the metal wires is vertical to a paper surface, and one end surface of each metal wire is parallel to the second polarization grid mesh; the second polarization grid mesh comprises a group of parallel metal wires, the wire grid direction of the second polarization grid mesh and the included angle of the large-caliber polarization grid mesh are 45 degrees, and the caliber area of the second polarization grid mesh is larger than a measured radiator or a reference metal flat plate of the measured object area.

In step P3, half of the signal from the large-aperture polarization grid is incident to the reference metal plate through the polarization grid, and the other half is reflected by the polarization grid; one part of the signal reflected by the polarized grid mesh is absorbed by the clutter absorption material, and the other part of the signal is received by the receiving antenna; the part of the signal reflected by the polarized grid network and received by the receiving antenna is identified and eliminated by the time domain gate technology of the network analyzer; the polarization attitude of the receiving antenna is horizontal polarization, namely the direction is parallel to the paper surface;

in the step P8, one half of the signals from the large-aperture polarized grid mesh are incident to the radiator to be tested through the polarized grid mesh, and the other half of the signals are reflected back by the polarized grid mesh; one part of the signal reflected by the polarized grid mesh is absorbed by the clutter absorption material, and the other part of the signal is received by the receiving antenna; the part of the signal reflected by the polarized grid network and received by the receiving antenna is identified and eliminated by the time domain gate technology of the network analyzer; the polarization attitude of the receiving antenna is horizontal polarization, i.e. the direction is parallel to the paper.

In step P5, the angle delta theta is 0.5-1 DEG, the axis of the receiving antenna is kept pointing to the center of the reference metal flat plate, and the reading of the network analyzer at the moment is recorded as S₂₁"Metal (Δ θ), defining the angle at this time as positive; when the receiving antenna is continuously moved to the nth position along the arc-shaped sliding rail, receivingThe included angle between the axis of the antenna and the normal of the reference metal flat plate is n x delta theta, and when the included angle between the axis direction of the receiving antenna and the normal direction of the reference metal flat plate is more than 40 degrees, the clockwise movement of the position of the receiving antenna is stopped, and the S is corrected₂₁Summing to obtain a process parameter a₁As shown in formula one:

a₁(Metal)＝S₂₁_Metal(θ₀)+S₂₁_Metal(Δθ)+…+S₂₁_Metal(n*Δθ)

in step P6, pair S₂₁Summing to obtain a process parameter a₂As shown in formula two:

a₂(Metal)＝S₂₁_Metal(θ₀)+S₂₁_Metal(Δθ)+…+S₂₁_Metal(n*Δθ)

in step P10, the angle delta theta is 0.5-1 DEG, the axis of the receiving antenna is kept pointing to the center of the radiator to be measured, and the reading of the network analyzer at the moment is recorded as S₂₁_BB(θ₀) (ii) a When the receiving antenna is continuously moved to the nth position along the arch-shaped slide rail, the included angle between the axis of the receiving antenna and the normal of the measured radiator is n x delta theta, and when the included angle between the axis direction of the receiving antenna and the normal direction of the measured radiator is more than 40 degrees, the clockwise movement of the position of the receiving antenna is stopped, and the S is corrected₂₁Summing to obtain a process parameter b₁As shown in formula three:

b₁(BB)＝S₂₁_BB(θ₀)+S₂₁_BB(Δθ)+…+S₂₁_BB(n*Δθ)

in step P11, pair S₂₁Summing to obtain a process parameter b₂As shown in formula four:

b₂(BB)＝S₂₁_BB(θ₀)+S₂₁_BB(Δθ)+…+S₂₁_BB(n*Δθ)。

the invention has the beneficial effects that:

in the technical scheme provided by the invention, scattering factor measurement is utilized to belong to relative measurement properties, based on the electromagnetic wave polarization separation principle, a transmitting antenna is placed outside an arched slide rail, the feeding of incident electromagnetic waves is realized through a large-caliber polarization grid mesh and another polarization grid mesh, the transmitting antenna does not completely shield and interfere with a receiving antenna on a physical structure, and meanwhile, a time domain gate technology is utilized to select a reflection signal of a required path, so that the whole scattering correction factor measurement problem including a dead zone is realized.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic diagram of a conventional normal emissivity measurement method;

FIG. 2 is a schematic diagram illustrating a testing principle of a terahertz scattering correction factor measuring system and method according to the present invention.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 2, the system for measuring the terahertz radiator scattering correction factor provided by the invention comprises a network analyzer 1, a transmitting module, a receiving module, a reflector 7, a large-caliber polarization grid 8, a second polarization grid 9, a measured radiator 10, a reference test flat plate and an arched slide rail 14;

one side of the arch mouth of the arched slide rail 14 faces towards a tested object area, one side of the arched slide rail 14, which faces away from the arch mouth, is provided with the network analyzer 1, the tested radiator 10 or a reference test flat plate is placed in the tested object area, the transmitting module is arranged at a position close to the lower end of the arched slide rail 14, and the receiving module is arranged on the arched slide rail 14; one end of the transmitting module is connected with the network analyzer 1, and the other end faces the reflector 7; the large-caliber polarization grid mesh 8 is arranged between the arched slide rail 14 and a measured object of the measured object area, and the second polarization grid mesh 9 is arranged between the large-caliber polarization grid mesh 8 and the measured object of the measured object area; the reflector 7 is positioned below the large-aperture polarization grid 8 to reflect the emission signal from the emission module to the large-aperture polarization grid 8, and the large-aperture polarization grid 8 reflects the electromagnetic wave of the emission signal from the reflector 7 to the second polarization grid 9. The reference test plate is embodied as a reference metal plate 11.

In the above embodiment, the transmission signal is sent by the transmission module of the network analyzer 1, reflected by the reflector 7 and then reaches the large-aperture polarization grid 8, the large-aperture polarization grid 8 reflects the electromagnetic wave of the transmission signal from the reflector 7 to the second polarization grid 9, and the signal reflected by the measured radiator 10 or the reference test panel passes through the second polarization grid 9 and enters the large-aperture polarization grid 8 through the signal of the second polarization grid 9; in the scheme, the scattering factor measurement belongs to the property of relative measurement, based on the electromagnetic wave polarization separation principle, the transmitting module is arranged at a position close to the lower end of the arched slide rail 14, the receiving module is arranged on the arched slide rail 14, namely, the transmitting antenna 3 is arranged outside the arched slide rail 14, the feeding of incident electromagnetic waves is realized through the large-caliber polarization grid mesh 8 and the other polarization grid mesh, the transmitting antenna 3 does not shield the receiving antenna 5 on the physical structure at all and does not interfere with the receiving antenna 5, meanwhile, the time domain gate technology is utilized to select the reflection signals of required paths, and the whole scattering correction factor measurement problem including dead zones is realized.

Specifically, the transmitting module includes a transmitting spread spectrum unit 2 and a transmitting antenna 3, the transmitting antenna 3 is connected to the network analyzer 1 through the transmitting spread spectrum unit 2, and the reference test plate is specifically a reference metal plate 11.

Specifically, the receiving module comprises a receiving spread spectrum unit 4 and a receiving antenna 5, the receiving antenna 5 is connected with the network analyzer 1 through the receiving spread spectrum unit 4, a flexible long cable 6 is connected between the receiving spread spectrum unit 4 and the network analyzer 1, and the receiving spread spectrum unit 4 and the receiving antenna 5 are not limited in movement on the arc-shaped slide rail 14 through the arrangement of the flexible long cable.

Preferably, the antenna further comprises a noise absorption material 13, the noise absorption material 13 is arranged on the side of the reflector 7 away from the emitting module, and the electromagnetic wave reflected by the second polarization grid 9 is partially absorbed by the noise absorption material 13.

Specifically, the test reference surface of the measured radiator 10 or the reference test flat plate in the measured object region is a vertical surface, and the area of the reference metal flat plate 11 is equivalent to the area of the measured radiator 10; the receiving spread spectrum unit 4 and the receiving antenna 5 are arranged in the normal direction of the test reference surface, and the center of the tested radiator 10 or the reference test flat plate is positioned on the center of a circle of the arc slide rail 14; the included angle between the large-caliber polarization grid 8 and the normal of the test reference surface is 45 degrees, the large-caliber polarization grid 8 comprises a group of parallel metal wires, the direction of the metal wires is vertical to the paper surface, and one end surface of each metal wire is parallel to the second polarization grid 9. According to the basic principle of a polarization grid, an electromagnetic wave with a polarization direction parallel to the wire grid of the second polarization grid 9 will be reflected to the second polarization grid 9.

The second polarization grid 9 is parallel to the test reference surface, the second polarization grid 9 comprises a group of parallel metal wires, the included angle between the wire grid direction of the second polarization grid 9 and the large-caliber polarization grid 8 is 45 degrees, the caliber area of the second polarization grid 9 is larger than a tested radiator 10 or a reference test flat plate of a tested object area, and signals reflected by the tested radiator or the reference test flat plate can pass through the second polarization grid 9.

The invention also provides a method for measuring the scattering correction factor of the terahertz radiator, which comprises the following steps:

p1, vertically placing the reference metal flat plate 11 on the displacement table 12 of the measured object area;

p2, placing the receiving spread spectrum unit 4 and the receiving antenna 5 of the network analyzer 1 in the normal direction of the reference metal flat plate 11, wherein the center of the reference metal flat plate 11 is located on the center of the arc slide rail 14; setting the included angle between the normal of the large-caliber polarization grid mesh 8 and the reference metal flat plate 11 to be 45 degrees, and setting the included angle between the wire grid direction of the second polarization grid mesh 9 and the large-caliber polarization grid mesh 8 to be 45 degrees;

p3, operating network analyzer 1 at S₂₁The mode is that the emission signal is sent by the emission frequency spreading unit 2 and the emission antenna 3 of the network analyzer 1 and then reflected by the reflector 7 to reach the large-aperture polarization grid 8, the large-aperture polarization grid 8 reflects the electromagnetic wave of the emission signal from the reflector 7 to the second polarization grid 9, and the signal reflected by the metal reference plate passes through the second polarization grid 9 and the first polarization grid 9The signal of the polarization grid 9 is incident to the large-caliber polarization grid 8;

p4, recording the reading of the network analyzer 1 at this time as S₂₁_Metal(θ₀)，S₂₁_Metal(θ₀) Taking the linear value, θ₀At this time, the angle is 0 degree, and the axis of the receiving antenna 5 is coincident with the normal of the reference metal flat plate 11;

p5, changing the position of the receiving antenna 5 along the arc-shaped slide rail 14 in the clockwise direction to make the included angle between the axis of the receiving antenna 5 and the normal of the reference metal flat plate 11 be delta theta, and recording the reading of the network analyzer 1 at the moment as S₂₁- "Metal (Δ θ); the receiving antenna 5 is moved further along the arcuate slide 14 to the nth position (indicated by 15 in fig. 2), and the reading of the network analyzer 1 at this time is recorded as S₂₁"Metal (n Δ θ), for S₂₁Summing to obtain a process parameter a₁；

P6, rotating the reference metal plate 11 by 90 degrees along the axis, repeating the steps P2-P5, and obtaining S₂₁Summing to obtain a process parameter a₂；

P7, replacing the reference metal plate 11 with the measured radiator 10, placing the receiving and spreading unit 4 and the receiving antenna 5 of the network analyzer 1 in the normal direction of the measured radiator 10, and locating the center of the plane formed by the tip of the measured radiator 10 on the center of the arc slide rail 14;

p8, operating network analyzer 1 at S₂₁In the mode, a transmission signal is transmitted by a transmission spread spectrum unit 2 and a transmission antenna 3 of a network analyzer 1 and then reflected by a reflector 7 to reach a large-aperture polarization grid 8, the large-aperture polarization grid 8 reflects electromagnetic waves from the reflector 7 to a second polarization grid 9, and the signal reflected by a detected radiator 10 passes through the second polarization grid 9 and is incident to the large-aperture polarization grid 8 through the signal of the second polarization grid 9;

p9, recording the reading of the network analyzer 1 at this time as S₂₁_BB(θ₀)，S₂₁_BB(θ₀) Taking the linear value, θ₀At this time, the angle is 0 degree, namely the axis of the receiving antenna 5 is coincided with the normal of the measured radiator 10;

p10, changing in a clockwise direction along arcuate rail 14The position of the receiving antenna 5 is such that the included angle between the axis of the receiving antenna 5 and the normal of the measured radiator 10 is delta theta, and the reading of the network analyzer 1 at the moment is recorded as S₂₁_BB(θ₀) (ii) a Continuing to move the receiving antenna 55 along the arcuate slide 14 to the nth position, the reading of the network analyzer 1 at this time is recorded as S₂₁BB (n × Δ θ), the process parameter b is obtained by summing the above S21₁；

P11, rotating the detected radiator 10 by 90 degrees along the axis, repeating the steps P8-P10, and summing S21 obtained in the process to obtain the process parameter b₂；

P12, the calculation method of the scattering correction factor S of the measured radiator 10 is shown in formula five:

S＝(b₁*b₂)/(a₁*a₂)。

according to the method for measuring the scattering correction factor of the terahertz radiator, the scattering factor measurement belongs to the property of relative measurement, based on the electromagnetic wave polarization separation principle, the transmitting antenna 3 is placed outside the arched slide rail 14, the feeding of incident electromagnetic waves is realized through the large-caliber polarization grid mesh 8 and the other polarization grid mesh, the transmitting antenna 3 does not completely shield the receiving antenna 5 on the physical structure and does not interfere with the receiving antenna, meanwhile, the time domain gate technology is used for selecting the reflection signal of a required path, and the whole scattering correction factor measurement problem including a dead zone is realized.

Wherein, the area of the reference metal flat plate 11 is equivalent to the area of the detected radiator 10; the transmitting antenna 3 is a linearly polarized antenna and the polarization attitude is vertical polarization, i.e. perpendicular to the paper.

Specifically, the large-caliber polarization grid 8 comprises a group of parallel metal wires, the direction of the metal wires is vertical to the paper surface, and one end surface of each metal wire is parallel to the second polarization grid 9; the second polarization grid 9 comprises a group of parallel metal wires, the included angle between the wire grid direction of the second polarization grid 9 and the large-caliber polarization grid 8 is 45 degrees, and the caliber area of the second polarization grid 9 is larger than a measured radiator 10 or a reference metal flat plate 11 of a measured object area.

Specifically, in step P3, half of the signal from the large-aperture polarization grid 8 is incident to the reference metal flat plate 11 through the polarization grid, and the other half is reflected back by the polarization grid; the signal reflected by the polarization grid is partially absorbed by the clutter absorbing material 13, and the other part is received by the receiving antenna 5, and the part of the signal is not reflected from the reference metal plate 1111 and can be identified and eliminated through the time domain gate technology of the network analyzer 1. The polarization attitude of the receiving antenna 55 is horizontal polarization, i.e., the direction is parallel to the paper; the part of the signal reflected by the polarized grid network and received by the receiving antenna 5 is identified and eliminated by the time domain gate technology of the network analyzer 1; the polarization attitude of the receiving antenna 5 is horizontal polarization, i.e. the direction is parallel to the paper surface;

in step P8, one half of the signal from the large-aperture polarization grid 8 is incident to the measured radiator 10 through the polarization grid, and the other half is reflected back by the polarization grid; a part of the signal reflected by the polarization grid is absorbed by the clutter absorption material 13, and the other part of the signal is received by the receiving antenna 5; the part of the signal reflected by the polarized grid network and received by the receiving antenna 5 is identified and eliminated by the time domain gate technology of the network analyzer 1; the polarization attitude of the receiving antenna 5 is horizontal polarization, i.e. the direction is parallel to the paper.

Further, in step P5, Δ θ is taken to be 0.5 ° to 1 °, while keeping the axis of the receiving antenna 5 pointing to the center of the reference Metal plate 11, and the reading of the network analyzer 1 at this time is recorded as S21_ Metal (Δ θ), which defines the angle at this time as the forward direction; when the receiving antenna 5 is continuously moved to the nth position along the arcuate sliding rail 14, the included angle between the axis of the receiving antenna 5 and the normal of the reference metal flat plate 11 is n × Δ θ, until the included angle between the axis direction of the receiving antenna 5 and the normal of the reference metal flat plate 11 is n × Δ θ greater than 40 degrees, the clockwise movement of the position of the receiving antenna 5 is stopped, and S21 is summed to obtain a process parameter a1, as shown in formula one (according to symmetry, the measured value when the angle is negative, that is, when the receiving antenna is moved in the counterclockwise direction along the arcuate sliding rail 14 may be replaced by the measured value when the antenna is moved in the positive direction):

a₁(Metal)＝S₂₁_Metal(θ₀)+S₂₁_Metal(Δθ)+…+S₂₁_Metal(n*Δθ)

in step P6, pair S₂₁Summing to obtain a process parameter a₂As shown in formula two:

a₂(Metal)＝S₂₁_Metal(θ₀)+S₂₁_Metal(Δθ)+…+S₂₁_Metal(n*Δθ)

in step P10, Δ θ is 0.5 ° to 1 °, while keeping the axis of the receiving antenna 5 pointing to the center of the measured radiator 10, and the reading of the network analyzer 1 at this time is recorded as S₂₁_BB(θ₀) (ii) a When the receiving antenna 5 is continuously moved to the nth position along the arcuate slide rail 14, the included angle between the axis of the receiving antenna 5 and the normal of the measured radiator 10 is n × Δ θ, until the included angle between the axis direction of the receiving antenna 5 and the normal of the measured radiator 10 is greater than 40 degrees, the clockwise movement of the position of the receiving antenna 5 is stopped, and for S, the position of the receiving antenna 5 is stopped₂₁Summing to obtain a process parameter b₁As shown in formula three:

b₁(BB)＝S₂₁_BB(θ₀)+S₂₁_BB(Δθ)+…+S₂₁_BB(n*Δθ)

in step P11, pair S₂₁Summing to obtain a process parameter b₂As shown in formula four:

b₂(BB)＝S₂₁_BB(θ₀)+S₂₁_BB(Δθ)+…+S₂₁_BB(n*Δθ)。

to further specifically explain the technical solution of the present invention, in conjunction with fig. 2, a more specific embodiment is provided below:

1. the radiator 10 to be measured is taken down, the reference metal plate 11 is placed on the displacement table 12, and the area of the reference metal plate 11 is equivalent to that of the radiator 10 to be measured.

2. The network analyzer receiving spread spectrum unit 4 and the receiving antenna 5 are arranged in the normal direction of the reference metal flat plate 11, and the center of the reference metal flat plate 11 is positioned on the center of a circle of the arc-shaped slide rail 14.

3. Network analyzer 1 operates at S₂₁Mode or S₁₂Mode, here assumed to be S₂₁Mode(s). The transmitting signal is sent out by a transmitting spread spectrum unit 2 and a transmitting antenna 3 of the network analyzer. The transmitting antenna 3 is a linearly polarized antenna and the polarization attitude is vertical polarization, i.e. perpendicular to the paper. Passing through a reflectorThe reflected light of 7 reaches a large-caliber polarization grid 8. Therefore, the large-diameter polarization grid 8 reflects the electromagnetic wave from the mirror 7 to the polarization grid 9.

4. The large-caliber polarization grid 8 and the normal line of the reference metal flat plate 11 form an included angle of 45 degrees, and the large-caliber polarization grid is composed of a group of parallel metal wires, the direction of the metal wires is vertical to the paper surface, and one end surface of the metal wires is parallel to the second polarization grid 9. According to the basic principle of a polarization grid, an electromagnetic wave with a polarization direction parallel to the wire grid of the polarization grid will be reflected to the second polarization grid 9.

5. The second polarization grid 9 is parallel to the reference surface of the reference metal flat plate 11 and is also composed of a group of parallel metal wires, but the included angle between the wire grid direction and the large-caliber polarization grid is 45 degrees, the caliber area is larger than that of the reference metal flat plate 11, and the placing position is close to the measured metal flat plate 11 as much as possible. Half of the signal from the large diameter polarization grid 8 is incident on the reference metal plate 11 through the second polarization grid 9, and half is reflected back by the second polarization grid 9. The reflected signal is partially absorbed by the clutter absorbing material 13, and the other part is received by the receiving antenna 5. This portion of the signal is not reflected from the reference metal plate 11 and can be identified and rejected by the time domain gating technique of the network analyzer. The polarization attitude of the receiving antenna 5 is horizontal polarization, i.e. the direction is parallel to the paper.

6. The signal reflected back through the metal reference plate 11 may pass through the second polarising grid 9.

7. The signals passing through the second polarization grid 9 are incident on the large aperture polarization grid 8, half of these signals are absorbed by the clutter absorption material 13 after reflection, and the other half are received by the receiving antenna 5 after reflection.

8. Record the reading of the network analyzer 1 at this time as S₂₁_Metal(θ₀)，S₂₁_Metal(θ₀) Taking the linear value, θ₀This is 0 degrees, i.e. the axis of the receiving antenna 5 coincides with the normal to the reference metal plane 11.

9. The position of the receiving antenna 5 is changed along the arc-shaped slide rail 14 in the clockwise direction, so that the included angle between the axis of the receiving antenna 5 and the normal of the reference metal flat plate 11 is delta theta, and the delta theta is 0.5-1 DEG, and simultaneously the axis of the receiving antenna 5 is keptPointing to the center of the reference metal plate 11 and recording the reading S of the network analyzer 1 at that time₂₁- "Metal (. DELTA.theta.). The angle at this time is defined as the positive direction.

10. Continuing to move the receiving antenna 5 to the nth position along the arcuate slide rail 14, wherein the included angle between the axis of the receiving antenna 5 and the normal of the reference metal flat plate 11 is n × Δ θ, and recording the reading of the network analyzer 1 at this time as S₂₁And (n) Δ θ), until the angle n Δ θ between the axial direction of the receiving antenna 5 and the normal direction of the reference Metal plate 11 is greater than 40 degrees. For the above S₂₁Summing to obtain a process parameter a₁As shown in equation (1). In terms of symmetry, the measurement of a negative angle, i.e., moving counterclockwise along the arcuate slide 14, may be replaced with a measurement of positive movement.

a₁(Metal)＝S₂₁_Metal(θ₀)+S₂₁_Metal(Δθ)+…+S₂₁_Metal(n*Δθ) (1)

11. Rotating the reference metal flat plate 11 by 90 degrees along the axis, repeating the steps 2-10, and obtaining S in the process₂₁Summing to obtain a process parameter a₂As shown in equation (2).

a₂(Metal)＝S₂₁_Metal(θ₀)+S₂₁_Metal(Δθ)+…+S₂₁_Metal(n*Δθ) (2)

12. The reference metal flat plate 11 is replaced by the measured radiator 10, the network analyzer receiving spread spectrum unit 4 and the receiving antenna 5 are arranged in the normal direction of the measured radiator 10, and the center of the plane formed by the tip of the measured radiator 10 is positioned on the center of the arc slide rail 14.

13. Network analyzer 1 operates at S₂₁Mode or S₁₂Mode, here assumed to be S₂₁Mode(s). The transmitting signal is sent out by a transmitting spread spectrum unit 2 and a transmitting antenna 3 of the network analyzer. The transmitting antenna 3 is a linearly polarized antenna and the polarization attitude is vertical polarization, i.e. perpendicular to the paper. After being reflected by the reflector 7, the light reaches the large-aperture polarization grid 8.

14. The large-caliber polarization grid 8 and the normal line of the reference metal flat plate 11 form an included angle of 45 degrees, and the large-caliber polarization grid is composed of a group of parallel metal wires, the direction of the metal wires is vertical to the paper surface, and one end surface of the metal wires is parallel to the second polarization grid 9. According to the basic principle of a polarization grid, an electromagnetic wave with a polarization direction parallel to the wire grid of the polarization grid will be reflected to the second polarization grid 9. Thus, the large diameter polarization grid 8 reflects the electromagnetic wave from the mirror 7 to the second polarization grid 9.

15. The second polarization grid 9 is parallel to the reference surface of the measured radiator 10 and is also composed of a group of parallel metal wires, but the included angle between the wire grid direction and the large-caliber polarization grid is 45 degrees, the caliber area is larger than that of the measured radiator 10, and the placing position is close to the measured radiator 10 as much as possible. Half of the signals from the large-aperture polarization grid 8 are incident to the measured radiator 10 through the second polarization grid 9, and half are reflected back by the second polarization grid 9. The reflected signal is partially absorbed by the clutter absorbing material 13, and the other part is received by the receiving antenna 5. This portion of the signal is not a reflection from the measured radiator 10 and can be identified and rejected by the time domain gating technique of the network analyzer. The polarization attitude of the receiving antenna 5 is horizontal polarization, i.e. the direction is parallel to the paper.

16. The signal reflected back by the radiator 10 to be measured can pass through the second polarization grid 9.

17. The signals passing through the second polarization grid 9 are incident on the large aperture polarization grid 8, half of these signals are absorbed by the clutter absorption material 13 after reflection, and the other half are received by the receiving antenna 5 after reflection.

18. Record the reading of the network analyzer 1 at this time as S₂₁_BB(θ₀)，S₂₁_BB(θ₀) Taking the linear value, θ₀At this time, it is 0 degree, i.e. the axis of the receiving antenna 5 coincides with the normal of the measured radiator 10.

19. Changing the position of the receiving antenna 5 along the arc-shaped slide rail 14 in the clockwise direction to make the included angle between the receiving antenna and the normal of the measured radiator 10 be delta theta, wherein the delta theta is 0.5-1 DEG, simultaneously keeping the axis of the receiving antenna 5 pointing to the center of the measured radiator 10, and recording the reading S of the network analyzer 1 at the moment₂₁_BB(Δθ)。

20. Continuing to move the receiving antenna 5 along the arcuate slide 14 to the nth position, where the axis of the receiving antenna 5 and the measured position areThe angle between the normal of the radiator 10 is n x Δ θ, and the reading of the network analyzer 1 at this time is recorded as S₂₁BB (n × Δ θ), until the angle n × Δ θ between the axial direction of the receiving antenna 5 and the normal direction of the measured radiator 10 is greater than 40 degrees. For the above S₂₁Summing to obtain a process parameter b₁As shown in equation (3). In terms of symmetry, the measurement of a negative angle, i.e., moving counterclockwise along the arcuate slide 14, may be replaced with a measurement of positive movement.

b₁(BB)＝S₂₁_BB(θ₀)+S₂₁_BB(Δθ)+…+S₂₁_BB(n*Δθ) (3)

21. Rotating the measured radiator 10 by 90 degrees along the axis, repeating the steps 13-20, and obtaining S in the process₂₁Summing to obtain a process parameter b₂As shown in equation (4).

b₂(BB)＝S₂₁_BB(θ₀)+S₂₁_BB(Δθ)+…+S₂₁_BB(n*Δθ) (4)

22. The calculation method of the scattering correction factor S of the measured radiator 10 is shown in equation (5). Since the measured radiator 10 is compared with the measured value of the reference metal flat plate 11, only the forward measured value is actually required.

S＝(b₁*b₂)/(a₁*a₂) (5)

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.