阅读说明：本技术 一种片上天线测量用探针馈电去嵌入方法 (Probe feed de-embedding method for on-chip antenna measurement ) 是由 刘潇 梁伟军 班浩 赵兴 于 2021-08-30 设计创作，主要内容包括：本发明公开了一种片上天线测量用探针馈电去嵌入方法,包括以下步骤：步骤一、采用探针馈电,得到探针和片上天线AOC的共同增益测量结果；步骤二、测量片上天线的空间插损参数和探针的散射参数；步骤三、对探针进行耦合去嵌入操作,从共同结果中将探针影响去除；步骤四、得到片上天线的准确增益修正值和端口反射系数。本发明具有以下技术效果：1、通过探针去嵌入方法,从共同结果中将探针影响去除,可以大幅度降低馈电探针影响,有效修正片上天线增益测量结果；2、相对于传统方法具有准确度高、普适性高的优点；3、解决了探针对于导波/空间场的耦合去嵌问题,对于提升片上天线测量准确度具有至关重要的意义。(The invention discloses a probe feed de-embedding method for measuring an on-chip antenna, which comprises the following steps: the method comprises the following steps that firstly, a probe is adopted for feeding, and a common gain measurement result of the probe and an on-chip antenna AOC is obtained; measuring a space insertion loss parameter of the on-chip antenna and a scattering parameter of the probe; step three, coupling de-embedding operation is carried out on the probes, and probe influence is removed from the common result; and step four, obtaining an accurate gain correction value and a port reflection coefficient of the on-chip antenna. The invention has the following technical effects: 1. the probe de-embedding method is adopted, the influence of the probe is removed from the common result, the influence of the feed probe can be greatly reduced, and the measurement result of the gain of the on-chip antenna can be effectively corrected; 2. compared with the traditional method, the method has the advantages of high accuracy and universality; 3. the problem of coupling de-embedding of the probe to the guided wave/space field is solved, and the method has a vital significance for improving the measurement accuracy of the on-chip antenna.)

1. A probe feed de-embedding method for measuring an on-chip antenna is characterized by comprising the following steps:

the method comprises the following steps that firstly, a probe is adopted for feeding, and a common gain measurement result of the probe and an on-chip antenna AOC is obtained;

measuring a space insertion loss parameter of the on-chip antenna and a scattering parameter of the probe;

step three, coupling de-embedding operation is carried out on the probes, and probe influence is removed from the common result;

and step four, obtaining an accurate gain correction value and a port reflection coefficient of the on-chip antenna.

2. The probe feed de-embedding method for on-chip antenna measurement according to claim 1, wherein the transmitting antenna is an on-chip antenna, one end of the probe feed is connected to a coaxial or waveguide interface of a circuit, the other end of the probe feed is in a coplanar waveguide form, and the receiving antenna is a coaxial or waveguide interface.

3. The probe-fed de-embedding method for on-chip antenna measurement according to claim 1, wherein the receiving antenna gain calculation formula is:wherein: g represents gain, subscripts R and T represent receive and transmit, respectively, transmit antenna gain, | S₂₁I is the measured insertion loss (minus the straight-through value) and λ is the wavelength.

4. The probe-fed de-embedding method for on-chip antenna measurement according to claim 1, wherein in the third step, the probe-coupled de-embedding step comprises:

step A: two-port network P scattering matrix S of probe is obtained through measurement_P；

And B: scattering matrix S of probe two-port network P_PConversion into a transmission matrix T_P；

And C: obtaining a scattering matrix S of a two-port network M through measurement in on-chip antenna measurement_MIs converted into a transmission parameter matrix T_M；

Step D: according to T_M＝T_P·T_APerforming matrix cascade operation to calculate and obtain the transmission matrix T of the two-port network A of the on-chip antenna AOC_A；

Step E: transmission matrix T of two-port network A for on-chip antenna AOC_AInto a scattering matrix S_AWill S_ASubstituting the parameters into a receiving antenna gain formula to obtain the gain of the on-chip antenna.

5. The probe-fed de-embedding method for on-chip antenna measurement according to claim 4, wherein in the step A,the probe is a passive device, S_P12And S_P21Are equal.

6. The probe-fed de-embedding method for on-chip antenna measurement according to claim 4, wherein in the step B,

7. the probe-fed de-embedding method for on-chip antenna measurement according to claim 4, wherein in the step C,

converted transmission parameter matrix

8. The probe-fed de-embedding method for on-chip antenna measurement as claimed in claim 1, wherein in the step D, T is used as the reference_M＝T_P·T_ATransforming to obtain T_A＝T_P ^-1·T_M，Obtaining:

T_A11＝(T_M11T_P22-T_M21T_P12)/(T_P11T_P22-T_P21T_P12)；

T_A12＝(T_M12T_P22-T_M22T_P12)/(T_P11T_P22-T_P21T_P12)；

T_A21＝(T_M21T_P11-T_M11T_P21)/(T_P11T_P22-T_P21T_P12)；

T_A22＝(T_M22T_P11-T_M12T_P21)/(T_P11T_P22-T_P21T_P12)。

9. the probe-fed de-embedding method for on-chip antenna measurement according to claim 3, 4, 7 or 8, wherein in the step E,to include only the actual scattering parameters after the on-chip antenna and the receiving antenna, S_A11Port reflection coefficient, S, for an on-chip antenna_A21Parameters for substituting a receive antenna gain formula, wherein: s_A21＝1/T_A11Specifically, S_A21＝S_P12S_M21/(S_M11S_P22-S_P11S_P22+S_P12S_P21)。

10. The probe-fed de-embedding method for on-chip antenna measurement as claimed in claim 9, wherein S is_A21Substitution intoAnd the gain of the on-chip antenna after the probe coupling can be obtained.

Technical Field

The invention relates to the technical field of antenna measurement, in particular to a probe feed de-embedding method for on-chip antenna measurement.

Background

The on-chip antenna AOC is a planar antenna formed by integrating an antenna on a dielectric substrate, has a series of advantages of light weight, low cost, easy integration, commonality with a carrier and the like, and has compact structure, low section, stronger mechanical stability and corrosion resistance. Design and measurement verification of on-chip antennas are also a current research hotspot.

The key parameters of the on-chip antenna are closer to those of the traditional discrete antenna, and the on-chip antenna has gain, a radiation directional diagram, port standing waves, efficiency and the like. However, as the feeding form of the on-chip antenna is changed from the traditional coaxial and waveguide form to the probe feeding form, the size of the probe is larger than that of the miniaturized on-chip antenna, the gain measurement result of the on-chip antenna is affected, and the measurement is more difficult than that of the traditional antenna.

The on-chip antenna measurement system is usually located in a microwave anechoic chamber, a network analyzer is used as core radio frequency equipment, a transmitting antenna is an on-chip antenna to be measured, and a receiving antenna is a standard gain horn antenna. The receiving antenna travels on a certain scanning frame to complete data acquisition at different spatial positions. The existing probe de-embedding method only directly subtracts the probe amplitude on the basis of the measured insertion loss, only considers the amplitude information, does not consider the phase and the reflection influence of the connection position of the probe and the on-chip antenna, and has large measurement error on the on-chip antenna gain.

Disclosure of Invention

The invention aims to provide a probe feed de-embedding method for on-chip antenna measurement, which is used for solving the problem of evaluation of the influence of probe feed on an antenna gain measurement result in on-chip antenna measurement.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a probe feed de-embedding method for on-chip antenna measurement comprises the following steps:

the method comprises the following steps that firstly, a probe is adopted for feeding, and a common gain measurement result of the probe and an on-chip antenna AOC is obtained;

measuring a space insertion loss parameter of the on-chip antenna and a scattering parameter of the probe;

step three, coupling de-embedding operation is carried out on the probes, and probe influence is removed from the common result;

and step four, obtaining an accurate gain correction value and a port reflection coefficient of the on-chip antenna.

Preferably, the transmitting antenna is an on-chip antenna, one end of the probe feed is connected to a coaxial or waveguide interface of the circuit, the other end of the probe feed is in a coplanar waveguide form, and the receiving antenna is a coaxial interface or waveguide interface.

Preferably, the receiving antenna gain calculation formula is:wherein: g represents gain, subscripts R and T represent receive and transmit, respectively, transmit antenna gain, | S₂₁I is the measured insertion loss (minus the straight-through value) and λ is the wavelength.

Preferably, in the third step, the probe coupling de-embedding step includes:

step A: two-port network P scattering matrix S of probe is obtained through measurement_P；

And B: scattering matrix S of probe two-port network P_PConversion into a transmission matrix T_P；

And C: obtaining a scattering matrix S of a two-port network M through measurement in on-chip antenna measurement_MIs converted into a transmission parameter matrix T_M；

Step D: according to T_M＝T_P·T_APerforming matrix cascade operation to calculate and obtain the transmission matrix T of the two-port network A of the on-chip antenna AOC_A；

Step E: transmission matrix T of two-port network A for on-chip antenna AOC_AInto a scattering matrix S_AWill S_ASubstituting the parameters into a receiving antenna gain formula to obtain the gain of the on-chip antenna.

Preferably, in the step A,the probe is a passive device, S_P12And S_P21Are equal.

Preferably, in the step B,

preferably, in the step C,

the transformed transmission parameter matrix is:

preferably, in said step D, T is_M＝T_P·T_AIs transformed to obtainObtaining:

T_A11＝(T_M11T_P22-T_M21T_P12)/(T_P11T_P22-T_P21T_P12)；

T_A12＝(T_M12T_P22-T_M22T_P12)/(T_P11T_P22-T_P21T_P12)；

T_A21＝(T_M21T_P11-T_M11T_P21)/(T_P11T_P22-T_P21T_P12)；

T_A22＝(T_M22T_P11-T_M12T_P21)/(T_P11T_P22-T_P21T_P12)。

preferably, in the step E,to include only the actual scattering parameters after the on-chip antenna and the receiving antenna, S_A11Is the port reflection coefficient of the antenna, S_A21Parameters for substituting a receive antenna gain formula, wherein: s_A21＝1/T_A11Specifically, S_A21＝S_P12S_M21/(S_M11S_P22-S_P11S_P22+S_P12S_P21)

Preferably, S is_A21Substitution intoAnd the gain of the on-chip antenna after the probe coupling can be obtained.

The invention has the following technical effects:

1. the probe de-embedding method is adopted, the influence of the probe is removed from the common result, the influence of the feed probe can be greatly reduced, and the measurement result of the gain of the on-chip antenna can be effectively corrected;

2. compared with the traditional method, the method has the advantages of high accuracy and universality;

3. the problem of coupling de-embedding of the probe to the guided wave/space field is solved, and the method has a vital significance for improving the measurement accuracy of the on-chip antenna.

Drawings

FIG. 1 is a schematic diagram of the gain of an antenna on a probe feed measurement chip according to the present invention;

FIG. 2 is a schematic diagram of a matrix cascade of the present invention;

FIG. 3 is a graph showing the measurement results of the transmission coefficient of probe T50A according to the present invention;

FIG. 4 is a graph showing the measurement results of the reflection coefficient of the probe T50A according to the present invention;

FIG. 5 is a graph illustrating the effect of probe T50A de-embedding on the gain measurement results according to the present invention.

Detailed Description

The technical solution of the present invention is further described below with reference to the following embodiments and the accompanying drawings.

The embodiment provides a probe feed de-embedding method for measuring an on-chip antenna, which comprises the following steps:

firstly, feeding by using a probe, and measuring to obtain a common gain measurement result of the probe and an on-chip antenna AOC;

measuring a space insertion loss parameter of the on-chip antenna and a scattering parameter of the probe;

step three, coupling de-embedding operation is carried out on the probes, and probe influence is removed from the common result;

and step four, obtaining an accurate gain correction value and a port reflection coefficient of the on-chip antenna.

For the conventional antenna measurement, the types of the transmitting antenna and the receiving antenna are similar, and the transmitting antenna and the receiving antenna are both fed through a coaxial interface or a waveguide interface, and if the gain of the transmitting antenna is known, the gain of the receiving antenna can be obtained by measuring the insertion loss.

The receiving antenna gain calculation formula is as follows:

wherein: g represents gain, subscripts R and T represent receive and transmit, respectively, transmit antenna gain, | S₂₁I is the measured insertion loss (minus the straight-through value) and λ is the wavelength.

Aiming at the measurement of the on-chip antenna, the types of the transmitting antenna and the receiving antenna are different, the transmitting antenna is the on-chip antenna and cannot be directly connected with the coaxial or waveguide interface for feeding, a probe is needed to be adopted for feeding, one end of the probe for feeding is connected into the coaxial or waveguide interface of the circuit, the other end of the probe for feeding is in a coplanar waveguide mode for feeding the on-chip antenna, and the receiving antenna is still in a coaxial or waveguide interface.

The calculation is carried out by adopting the formula (1), as shown in figure 1, the obtained gain measurement result is a common result of the probe and the on-chip antenna AOC to be measured, and in order to obtain the gain of the on-chip antenna to be measured, the probe needs to be subjected to coupling de-embedding operation, so that the invention discloses a probe feeding de-embedding method for on-chip antenna measurement.

In a further implementation manner of this embodiment, in the second step, the scattering parameters of the probe are measured, and the factory report only has amplitude data and no phase information, and thus coupling de-embedding cannot be performed.

In a further embodiment of this embodiment, in the third step, the step of probe coupling de-embedding includes:

step A: two-port network P-scattering of the probe is measuredMatrix S_P；

And B: scattering matrix S of probe two-port network P_PConversion into a transmission matrix T_P；

And C: obtaining a scattering matrix S of a two-port network M through measurement in on-chip antenna measurement_MIs converted into a transmission parameter matrix T_M；

Step D: according to T_M＝T_P·T_APerforming matrix cascade operation to calculate and obtain the transmission matrix T of the two-port network A of the on-chip antenna AOC_A；

Step E: transmission matrix T of two-port network A for on-chip antenna AOC_AInto a scattering matrix S_AWill S_ASubstituting the parameters into a receiving antenna gain formula to obtain the gain of the on-chip antenna.

According to the formula (1), S₂₁Can be measured by a network analyzer, as shown in fig. 2, the measured portion in the dashed box is considered as a two-port network having four scattering parameters:

the probe portion can also be considered as a two-port network, with the scattering parameters expressed as:

because M is P.A, the scattering parameter of the two-port network at the antenna position is obtained by adopting the inverse operation of matrix cascade

Will S_A12Substituting equation (1) to calculate the gain of the AOC, S in the matrix_A11Namely the reflection coefficient of the antenna port on the chip to be tested.

Conventional probe de-embedding method for shadow of probe feedThe noise removal basically adopts S directly measured_m21Removing probes S on the basis of amplitude_P21Of (d), i.e. | S_A21|＝|S_m21|-|S_P21In (dB), this approach is a simplified form and approximation of the method of the invention, provided that probe S is used_P22And an on-chip antenna S_A11The situation is better, the phase is not considered, and the reflection influence at the joint of the probe and the on-chip antenna is not considered. Through actual measurement, the probe S is often found_P22And an on-chip antenna S_A11The simplified formula is not ideal and the error of the gain measurement of the on-chip antenna is large.

The probe coupling de-embedding method in the second step is adopted, so that the method has the characteristic of universality for the on-chip antenna measuring system, the characteristics of the on-chip antenna to be measured do not need to meet certain conditions, and the probe de-embedding correction can be carried out by using the method only by measuring the space insertion loss scattering parameters of the on-chip antenna and the scattering parameters of the probe, so that the accurate gain correction value and the port reflection coefficient of the on-chip antenna are obtained, and the method has the characteristic of high accuracy compared with the traditional method.

In a further embodiment of this embodiment, in step a,the probe is a passive device, S_P12And S_P21Are equal.

In a further embodiment of this embodiment, in step B,

in a further embodiment of this embodiment, in step C,

the transformed transmission parameter matrix is:

in a further embodiment of this embodiment, in step D, T is_M＝T_P·T_AIs transformed to obtain

Obtaining:

T_A11＝(T_M11T_P22-T_M21T_P12)/(T_P11T_P22-T_P21T_P12)；

T_A12＝(T_M12T_P22-T_M22T_P12)/(T_P11T_P22-T_P21T_P12)；

T_A21＝(T_M21T_P11-T_M11T_P21)/(T_P11T_P22-T_P21T_P12)；

T_A22＝(T_M22T_P11-T_M12T_P21)/(T_P11T_P22-T_P21T_P12) (8)

in a further embodiment of this embodiment, in step E,to include only the actual scattering parameters after the on-chip antenna and the receiving antenna, S_A11Port reflection coefficient, S, for an on-chip antenna_A21Parameters for substituting a receive antenna gain formula, wherein:

S_A11＝T_A21/T_A11

S_A12＝(T_A11T_A22-T_A21T_A12)/T_A11

S_A21＝1/T_A11

S_A22＝T_A12/T_A11 (9)

specifically, S_A11＝(S_M11-S_P11)/(S_M11S_P22-S_P11S_P22+S_P12S_P21)

S_A12＝(S_M12S_M21+S_P11S_M22-S_M11S_M22)/S_M21S_P12-S_A11(S_M22S_P11S_P22+S_M12S_M21S_P22-S_M22S_P12S_P21-S_M11S_M22S_P22)/S_M21S_P12 (10)

S_A21＝S_P12S_M21/(S_M11S_P22-S_P11S_P22+S_P12S_P21)

S_A22＝(S_M22S_P11S_P22-S_M22S_P12S_P21-S_M11S_M22S_P22+S_M12S_M21S_P22)/(S_M11S_P22-S_P11S_P22+S_P12S_P21)

In a further embodiment of this example, S of formula (10)_A21And (3) substituting the formula (1) to obtain the gain of the on-chip antenna after the probe is coupled.

The method comprises the following specific implementation steps:

the on-chip antenna was measured using a feed probe model T50A (abbreviated probe T50A):

as shown in FIGS. 3 and 4, for probe T50A, the scattering matrix parameter, | S₂₁And according to the traditional on-chip antenna measurement method, only the amplitude is considered for correction, and the corrected gain difference is 0.41dB @32.2 GHz.

As shown in fig. 5, in order to influence the gain measurement result of the on-chip antenna to be measured by using the method of the present invention, it can be seen that the maximum correction value of the probe T50A to the gain measurement result of the on-chip antenna is 0.74dB @32.2 GHz; namely, at 32.2GHz, the difference of 0.74dB-0.41dB between the method and the simplified method is 0.33dB, and for the requirement of the uncertainty of the on-chip antenna measurement of 0.5dB, probe feed de-embedding is an important influence quantity and has a vital significance for improving the measurement accuracy of the on-chip antenna.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.