阅读说明：本技术 一种近场聚焦全息阵列天线及调控方法 (Near-field focusing holographic array antenna and regulation and control method ) 是由 章秀银 周哲 苏华峰 姚逸慧 于 2020-12-04 设计创作，主要内容包括：本发明公开了一种近场聚焦全息阵列天线及调控方法,包括SIW波导及同轴馈电结构,所述SIW波导的上表面及下表面分别设置上层金属板及下层金属板,所述上层金属板设置缝隙辐射单元,所述SIW波导中填充波导介质材料,所述波导介质材料中插入金属柱,所述SIW波导的两侧设置延伸波导,所述延伸波导的末端加载超材料吸收边界,所述缝隙辐射单元包括缝隙阵列,每个缝隙设置射频开关,所述同轴馈电结构设置在SIW波导的中心处,向两侧的延伸波导传播TE-(10)模电磁波。本发明天线,通过近场聚焦,令辐射能量尽可能地聚集在焦点处,聚焦的效果非常明显。(The invention discloses a near-field focusing holographic array antenna and a regulation and control method, the near-field focusing holographic array antenna comprises an SIW waveguide and a coaxial feed structure, the upper surface and the lower surface of the SIW waveguide are respectively provided with an upper metal plate and a lower metal plate, the upper metal plate is provided with a slot radiation unit, the SIW waveguide is filled with waveguide dielectric materials, metal columns are inserted into the waveguide dielectric materials, extension waveguides are arranged at two sides of the SIW waveguide, the tail end of each extension waveguide is loaded with a metamaterial absorption boundary, the slot radiation unit comprises a slot array, each slot is provided with a radio frequency switch, the coaxial feed structure is arranged at the center of the SIW waveguide, and TE is transmitted to the extension waveguides at two sides 10 A mode electromagnetic wave. The antenna of the inventionThrough near-field focusing, the radiation energy is focused at the focal point as much as possible, and the focusing effect is very obvious.)

1. The near-field focusing holographic array antenna is characterized by comprising an SIW waveguide and a coaxial feed structure, wherein an upper layer metal plate and a lower layer metal plate are respectively arranged on the upper surface and the lower surface of the SIW waveguide, a slot radiation unit is arranged on the upper layer metal plate, a waveguide dielectric material is filled in the SIW waveguide, a metal column is inserted in the waveguide dielectric material, extension waveguides are arranged on two sides of the SIW waveguide, a metamaterial absorption boundary is loaded at the tail end of each extension waveguide, each slot radiation unit comprises a slot array, a radio frequency switch is arranged in each slot, the coaxial feed structure is arranged at the center of the SIW waveguide, and TE is transmitted to the extension waveguides on two sides₁₀A mode electromagnetic wave.

2. A near field focusing holographic array antenna according to claim 1, wherein the metamaterial absorption boundary comprises periodically arranged square patches, a dielectric layer and a metal layer, the metal layer is arranged on a lower surface of the dielectric layer, and the square patches are arranged on an upper surface of the dielectric layer.

3. The near field focusing holographic array antenna according to claim 1, wherein the radio frequency switch comprises a filtering branch, a low pass feeding branch and a switch tube connected in sequence, metal patches are disposed on two sides of the switch tube, one metal patch is disposed between the low pass feeding branch and the switch tube and connected to an anode of the switch tube, the other metal patch is connected to a cathode of the switch tube, and the metal patches on the two sides form a short circuit when the switch tube is turned on, so that the gap cannot work, and the gap radiation unit is turned off.

4. A near field focusing holographic array antenna of claim 3, wherein the metal patch connected to the negative electrode of the switch tube is connected to the upper metal plate through the short circuit metal post.

5. The near-field focusing holographic array antenna of claim 3, wherein the metal patches on both sides of the switching tube are symmetrically arranged, and the metal patches on both sides form equivalent capacitance and inductance with the upper metal plate to generate parallel resonance, thereby realizing short circuit between the metal patches and the upper metal plate.

6. The near-field focusing holographic array antenna of claim 1, wherein the SIW waveguide is a two-port constant amplitude power divider, and two output ports of the constant amplitude power divider are respectively connected to the extension waveguide.

7. A near field focusing holographic array antenna as claimed in claim 1, wherein adjacent slots in the slot array are spaced one tenth of a wavelength apart.

8. A near field focusing holographic array antenna according to claim 1, wherein said coaxial feed structure comprises a coaxial line, an inner core of the coaxial line is connected with the waveguide dielectric material, an outer core is connected with the lower metal plate, and the signal is fed by an SMA head.

9. A near field focusing holographic array antenna of claim 3, wherein said switch is a pin or a varactor.

10. A method for controlling a near field focusing holographic array antenna according to any of claims 1 to 9, wherein the method for controlling is based on an amplitude weighting method, in particular:

step 1: writing a unit excitation phase weighting formula corresponding to the preset focus in the free space according to the phase calculation formula and the rectangular coordinate of the preset focus:

A＝cos(∠ψ₀-∠(ψ_r)^*)

step 2: calculating the phase weighted distribution of each gap on the upper metal plate of the SIW waveguide to obtain a two-dimensional matrix, and judging the values in the matrix through a formula:

making the matrix element values only 0 and 1, wherein T is a preset threshold value;

and step 3: determining the state of the radio frequency switch at each corresponding position according to the 1/0 value in the matrix obtained in the step 2, applying corresponding direct current bias voltage to all the radio frequency switches through the FPGA control circuit and the direct current bias network to control the on-off of the radio frequency switches, wherein the direct current bias voltage applied when the element value is 1 is greater than the on-off threshold value of the radio frequency switches, the corresponding radio frequency switches are turned on, the direct current bias voltage applied when the element value is 0 is less than the on-off threshold value of the radio frequency switches, and the corresponding radio frequency switches are turned off;

and 4, step 4: and if the position of the preset focus is changed, repeating the steps 1 to 3.

Technical Field

The invention relates to the technical field of holographic antennas, in particular to a near-field focusing holographic array antenna and a regulating and controlling method.

Background

The holographic principle starts physical optics, and means that a holographic structure is used for recording interference fringes formed by the coherence of a reference wave and an object wave to obtain the holographic structure, and the holographic structure is irradiated by the reference wave to diffract the object wave. Compared with the traditional film which can only record the illumination intensity, the holographic structure can record the intensity and phase information of the object wave at the same time, thereby realizing the reproduction of the object image.

Unlike the optical field, which has many materials capable of recording beam interference information, the recording material in the microwave field has been a difficult problem to solve, which has prevented the application of the holographic technology in the microwave field for a long time. In 1968, the holographic technology is applied to the microwave field for the first time by P.F. Checcaccci, the holographic technology records holographic patterns by adjusting the thickness of a hard paraffin plate, the area of a metal patch, the position of a metal strip and the like, and a holographic antenna with a VHF frequency band is designed based on the holographic patterns. In 2007, according to the electromagnetic field uniqueness theorem, the p.soriyadevan realizes the recording of the holographic pattern by placing the metal strip at the minimum point of the interference field to simulate the boundary condition of the ideal electric wall, but the holographic structure only records the minimum value of the interference field, the recording of the holographic pattern is not accurate enough, and the error between the reduced object wave and the original wave is large. Darwin Blanco and Eva Rajo-Iglesias in 2012 excited TM in a planar parallel waveguide₀The electromagnetic wave of the mode controls the radiation unit on the parallel waveguide according to the phase distribution and the focus position on the parallel waveguide, thereby realizing the effect of near-field focusing

The holographic antenna technology is characterized in that a target beam is integrally recorded on a holographic structure through microwave materials and processes, and when the holographic structure is fed through a source antenna, the target beam can be restored through diffraction. The holographic antenna technology gives consideration to the performance, cost and volume of the antenna, and is an important development branch of the millimeter wave antenna.

Many methods for holographic structure design have been proposed, such as placing metal strips at the interference field minima, designing arrays of metal patches of different sizes, integrated from the impedance surface, and feeding with dipoles at the center of the array. In addition, the transverse feed longitudinal rectangular waveguide slot array, the coaxial feed single slot array in the radial waveguide, the reflection elimination slot pair spiral array, the dipole and the dielectric resonant antenna can realize the construction of the holographic structure.

In practical operation, the focusing array antenna can be applied to the energy transmission process. Compared with the traditional energy transmission antenna, the focusing array antenna can improve the energy transmission efficiency through focusing and reduce the energy loss in the transmission process. By improving the focusing array antenna, radiation focusing of a plurality of focuses is formed, the antenna can be applied to multi-beam communication, the energy utilization efficiency is improved, and the communication quality of users in different directions is improved under the condition that the communication distance is not changed. In the working process of the low-orbit satellite, electromagnetic waves are required to penetrate through the atmosphere for communication between the satellite and the ground, and the communication quality is seriously reduced due to the large communication distance; if the technology of the focusing antenna is adopted, the electromagnetic wave energy transmitted to the ground by the satellite antenna in parallel can be converged on a single point, the energy received by the ground base station is improved, the information distortion caused by the communication distance is reduced, and the energy used for the communication of the satellite can be saved. Compared with 2/3/4G communication, the attenuation of the signal on the transmission path is extremely obvious due to the greatly increased working frequency of the base station of 5G/6G communication, which causes the signal to be sharply reduced along with the increase of the distance; if the signal is transmitted by adopting a focusing method, the energy transmitted in parallel is focused on a plurality of points, 5G/6G communication service can be provided for a plurality of directions simultaneously, and the effective transmission distance of the signal of the high-frequency base station can be increased.

Disclosure of Invention

In order to overcome the disadvantages and shortcomings of the prior art, a primary object of the present invention is to provide a near-field focusing holographic array antenna. The antenna provided by the invention is based on the holographic principle, and can realize single-point energy focusing in a near field area.

The invention provides a method for regulating a near-field focusing holographic array antenna.

The invention adopts the following technical scheme:

a near-field focusing holographic array antenna comprises SIW waveguideThe upper surface and the lower surface of the SIW waveguide are respectively provided with an upper metal plate and a lower metal plate, the upper metal plate is provided with a slot radiation unit, the SIW waveguide is filled with waveguide dielectric materials, metal columns are inserted into the waveguide dielectric materials, extension waveguides are arranged on two sides of the SIW waveguide, the tail end of each extension waveguide is loaded with a metamaterial absorption boundary, each slot radiation unit comprises a slot array, each slot is provided with a radio frequency switch, the coaxial feed structure is arranged at the center of the SIW waveguide and transmits TE to the extension waveguides on two sides₁₀A mode electromagnetic wave.

Furthermore, the metamaterial absorption boundary comprises periodically arranged square patches, a dielectric layer and a metal layer, wherein the metal layer is arranged on the lower surface of the dielectric layer, and the square patches are arranged on the upper surface of the dielectric layer.

Further, the radio frequency switch is including the filtering minor matters, low-pass feed minor matters and the switch tube that connect gradually, the switch tube both sides set up the metal paster, and one side metal paster sets up between low-pass feed minor matters and switch tube, and is connected with the positive pole of switch tube, and opposite side metal paster is connected with the negative pole of switch tube, and the metal paster of both sides forms the short circuit when the switch tube switches on for the unable work in gap closes the gap radiation unit.

Furthermore, the metal patch connected with the negative electrode of the switch tube is connected with the upper layer metal plate through the short circuit metal column.

Furthermore, the metal patches on the two sides of the switch tube are symmetrically arranged, and the metal patches on the two sides form equivalent capacitance and inductance with the upper metal plate to generate parallel resonance, so that short circuit between the metal patches and the upper metal plate is realized.

Further, the SIW waveguide is a two-port constant amplitude power divider, and two output ports of the constant amplitude power divider are respectively connected with the extension waveguide.

Further, in the slot array, adjacent slots are spaced one tenth of a wavelength apart.

Furthermore, the coaxial feed structure comprises a coaxial line, the inner core of the coaxial line is connected with the waveguide dielectric material, the outer core of the coaxial line is connected with the lower layer metal plate, and signals are fed in by the SMA head.

Further, the switch tube is a pin tube or a varactor.

The invention adopts the following technical scheme

A method for regulating and controlling a near-field focusing holographic array antenna adopts an amplitude weighting-based method, and specifically comprises the following steps:

step 1: writing a unit excitation phase weighting formula corresponding to the preset focus in the free space according to the phase calculation formula and the rectangular coordinate of the preset focus:

A＝cos(∠ψ₀-∠(ψ_r)^*)

step 2: calculating the phase weighted distribution of each gap on the upper metal plate of the SIW waveguide to obtain a two-dimensional matrix, and judging the values in the matrix through a formula:

making the matrix element values only 0 and 1, wherein T is a preset threshold value;

and step 3: determining the state of the radio frequency switch at each corresponding position according to the 1/0 value in the matrix obtained in the step 2, applying corresponding direct current bias voltage to all the radio frequency switches through the FPGA control circuit and the direct current bias network to control the on-off of the radio frequency switches, wherein the direct current bias voltage applied when the element value is 1 is greater than the on-off threshold value of the radio frequency switches, the corresponding radio frequency switches are turned on, the direct current bias voltage applied when the element value is 0 is less than the on-off threshold value of the radio frequency switches, and the corresponding radio frequency switches are turned off;

and 4, step 4: and if the position of the preset focus is changed, repeating the steps 1 to 3.

The invention has the beneficial effects that:

(1) the invention provides a holographic focusing concept different from holographic beam forming, controls the position and the number of working gaps in a gap array through digital coding, can effectively form a focus at a single target point in a near-field radiation area, obviously converges radiation energy with the target focus, can be combined with energy transmission, and improves the transmission efficiency of short-distance energy.

(2) Compared with a large holographic array antenna, the invention adopts the SIW structure, has the advantages of small volume and simple structure, and is more beneficial to realizing a radio frequency system with high integration level.

(3) Slot antenna arrays are easier to manufacture and more densely arranged than patch or dipole antennas. The holographic focusing is carried out in a slot array antenna mode, the radiation aperture of the antenna can be enlarged, the radiation efficiency of the antenna is further improved, and the energy focusing effect is enhanced.

Drawings

FIG. 1 is a top view of a 10x200 array of a near field holographic focusing array antenna embodying the present invention;

FIG. 2 is an exploded view of a near field holographic focusing array antenna according to the present invention;

FIG. 3 is a perspective view of a metamaterial absorbent boundary in accordance with an embodiment of the present invention;

FIG. 4 is a schematic exploded view of a metamaterial absorption boundary periodic unit according to an embodiment of the present invention;

FIG. 5 is a perspective view of a loaded slot unit structure of the RF switch according to an embodiment of the present invention;

FIG. 6 is a perspective view of a loaded slot unit structure of the RF switch without the shorting metal post according to an embodiment of the present invention;

fig. 7 is a graph of simulation results for a 10x200 array example of the present invention focused at a focal point of x 0, y 0, and z 120 mm.

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the present invention is not limited to these examples.

Examples

As shown in fig. 1, 2 and 4, a near-field focusing holographic array antenna includes a SIW waveguide and a coaxial feed structure 7, where the coaxial feed structure is connected to the SIW waveguide and is used to control input powers of two extended waveguides at two sides to be as same as possible and calculate an electromagnetic wave phase distribution on the extended waveguides. In the coaxial feed structure, the inner core of the coaxial line is inserted into the SIW waveguide dielectric material 3, and the outer core is connected with the lower layer of the radial waveguideA metal plate 6, the signal is fed by the SMA head, TE is propagated to the extended waveguides at the center of the SIW waveguide and at the two sides₁₀A mode electromagnetic wave.

The SIW waveguide is of a rectangular structure, an upper metal plate 1 and a lower metal plate 6 are arranged on the upper surface and the lower surface of the SIW waveguide respectively, a slot radiation unit 2 is arranged on the upper metal plate and comprises a slot array formed by N x M slots, a radio frequency switch is arranged in each slot, a Rogers RO4003 dielectric material is filled in an inner cavity of the SIW waveguide, a plurality of metalized through holes are punched in the waveguide dielectric material 3, and metal columns 4 are inserted for forming a waveguide structure which is equivalent to a waveguide wall. Extended waveguides are arranged on both sides of the SIW waveguide, the ends of which are loaded with metamaterial absorption boundaries 5.

The SIW waveguide structure comprises a two-port constant-amplitude power divider, two outputs of the constant-amplitude power divider are respectively connected with the extension waveguide, and the constant-amplitude power divider is used for uniformly distributing power input into the SIW extension waveguide.

The power divider structure is enabled to evenly distribute the output power to the extension waveguides of the power dividing ports by adjusting the size of the power divider and the position and size of the metal posts inserted into the power divider SIW structure. Furthermore, the energy output by the power divider into the SIW extension waveguide is controlled to be equal, so that the slot units distributed on the SIW extension waveguide radiate the equal energy, and the radiation aperture of the whole antenna is improved.

And calculating the phase distribution of the slot radiation unit on the SIW waveguide feed structure, namely the phase distribution of the reference wave in the holographic near-field focusing model, through the port output phase of the constant-amplitude power division structure and the phase propagation of the SIW extension waveguide.

The slot in the slot radiating element has a length of about 0.22 wavelength and a width of about 0.045 wavelength.

The width of the extension waveguide is slightly less than 0.5 time of wavelength, the height of the extension waveguide is 0.137 time of wavelength, and the length of the extension waveguide is more than 10 times of wavelength.

The diameter of a metal column in the SIW waveguide is 0.027 times of wavelength, and the circle center distance of the metal column is 0.072 times of wavelength.

The power input to the SIW waveguide by the power divider is constant amplitude.

The depth of the coaxial feed structure extending into the power divider is 0.1 time of the wavelength.

As shown in fig. 3, the metamaterial absorption boundary includes: the metal layer is arranged on the lower surface of the dielectric layer, and the square patches are arranged on the upper surface of the dielectric layer periodically. The dielectric layer is rectangular, specifically is a high-loss dielectric FR4 material, and the metal layer is a high-conductivity metal thin layer. The metamaterial absorption boundary absorbs the energy of the unnecessary SIW waveguide electromagnetic waves which are not radiated after being transmitted from the central coaxial feed through the periodically arranged square patches, the high-conductivity metal thin layer and the high-loss medium FR4, the approximation of the traveling waves in the waveguide is realized under the combined action, the radiation performance disturbance and deterioration caused by the reflected waves are reduced, and the good wave absorption effect is realized in a wide range.

The gap array sets up at upper metal sheet, and a plurality of gaps evenly distributed is on the metal sheet, and the interval between the adjacent gap is one tenth wavelength, and the interval in this embodiment is 1mm, suitably reduces the interval of gap and can improve the density of gap when not influencing the control of gap, increases the radiation gap number of selecting, improves whole gain.

As shown in fig. 5, the radio frequency switch includes filtering minor matters, low-pass feed minor matters 12 and switch tube 11 that connect gradually, the switch tube is pin diode or varactor, the switch tube both sides set up the metal paster, and one side metal paster sets up between low-pass feed minor matters and switch tube, and is connected with the positive pole of switch tube, and opposite side metal paster is connected with the negative pole of switch tube, and the metal paster of both sides forms the short circuit when the switch tube switches on for the unable work in gap closes the gap radiation unit.

In this embodiment, the metal patches on both sides are called a left metal patch 13 connected to the anode of the diode, and the metal patches on both sides are called a right metal patch 14 connected to the cathode of the diode.

When the low-pass feed branch is not loaded with a direct-current power supply, the added pin diode and the metal patch have no influence on the gap radiation, and the gap radiation unit radiates normally. When a direct current power supply is loaded on the low-pass feed branch, a low-pass filtering effect is generated on the passing current, high-frequency components of 23GHz-30GHz in the passing current are filtered, and the influence on a radiation gap is reduced. The low-pass feed branch is used as a direct current bias circuit to provide direct current voltage for the PIN diode. A large equivalent capacitor is formed between the left metal patch and the upper metal plate of the SIW waveguide, and the left metal patch is equivalent to an inductor under the condition of high frequency, so that parallel resonance is generated between the left metal patch and the upper metal plate under the condition of high frequency, and the short circuit effect is generated.

Realize the short circuit between right side metal patch and the upper metal sheet and have two kinds of modes, firstly the right side metal patch is connected with the upper metal sheet through short circuit metal column 15, also is equivalent to the short circuit between the two. When the direct current power supply makes the pin pipe switch on, the metal paster short circuit of pin pipe left and right sides, therefore two metal paster make the radiation gap both sides short circuit of below, and the unable normal work of gap unit has played the effect of closing the gap unit.

As shown in fig. 6, another way is: the metal patches on the two sides are symmetrically arranged on the two sides of the switch tube, namely, the distance between the metal patches and the switch tube is equal, the metal patches on the left side and the right side generate parallel resonance through forming equivalent capacitance and inductance, and short circuit between the metal patches and the metal plate on the upper surface of the SIW waveguide is realized.

In this embodiment, the operating frequency band is 26.5-28GHz, and a size label diagram of the corresponding slot antenna unit and the corresponding radio frequency switch is shown in fig. 5, where the specific parameters are as follows:

l2.45 mm, W0.5 mm, L1 1.5mm, W1 2mm, L2 2mm, W2 0.1mm, L3 1.2mm, W3 1mm, S0.8 mm, D0.3 mm, H1.524 mm. In this embodiment, a Rogers4003 plate is used as the dielectric material for filling the SIW waveguide, and has a relative dielectric constant of 3.55, a length L0-208.9 mm, a height H-1.524 mm, and a width W0-60.6 mm. The center frequency is 27GHz, the corresponding gap unit spacing is 1/10 guided wave wavelengths, the gap is 1mm, and the number of array elements is 10x 200.

The method for regulating and controlling the antenna adopts a regulation and control method based on an amplitude weighting formula, and the formula and the steps are as follows:

step 1: writing a unit excitation phase weighting formula corresponding to the preset focus in the free space according to the phase calculation formula and the rectangular coordinate of the preset focus:

A＝cos(∠ψ₀-∠(ψ_r)^*)

step 2: calculating the phase weighted distribution of each slot unit on the metal plate on the upper surface of the SIW rectangular waveguide to obtain a two-dimensional matrix, and judging the values in the matrix through a formula:

and judging to ensure that the element values of the obtained matrix are only 0 and 1, wherein T is a preset threshold value, and focusing needs an accurate phase, so that the threshold value range is 0.9-1, and the working state of the radiation unit is regulated and controlled through the threshold value.

And step 3: and (3) determining the state of the radio frequency switch at each corresponding position according to the 1/0 value in the matrix obtained in the step (2), and applying corresponding direct current bias voltage to all the radio frequency switches through the FPGA control circuit and the direct current bias network so as to control the on-off of the radio frequency switches. When the element value is 1, the applied direct current bias voltage is greater than the conduction threshold value of the element value, the corresponding radio frequency switch is switched on, and when the element value is 0, the applied direct current bias voltage is less than the conduction threshold value of the element value, the corresponding radio frequency switch is switched off;

and 4, step 4: and if the position of the preset focus is changed, repeating the steps 1 to 3.

According to the antenna, according to the optical interference principle, the gap distribution on the SIW waveguide is equivalent to the interference fringe formed by the reference wave and the target radiation field on the waveguide plane when the reference wave is injected, and the obtained interference fringe is used for controlling a radio frequency switch above the gap.

According to the imaging principle of light, reference waves are used for exciting interference fringes, and if the phases of an obtained target radiation field and the reference waves are opposite, the radiation field formed by the interference fringes in the space can be converged at the focal point of the target radiation field through inversion on a time domain.

The invention utilizes the optical imaging and interference principle, combines the radiation gap phase distribution obtained by calculation through time reversal, and obtains the gap switch matrix required by forming single-point focusing through calculation by a phase formula and a weighting formula for the switch state of a gap unit. The holographic array focuses the radiation energy as much as possible at the focal point by near field focusing.

Fig. 7 shows a radiation energy distribution diagram of a near-field focusing holographic array antenna according to a 10 × 200 embodiment of the present invention. The preset focus of the near-field focusing holographic array is located at a position where x is 0, y is 0, and z is 120mm, an obvious focus is formed at the preset focus by energy distribution obtained through simulation, the focus exists in the form of a focal spot, and the 3dB width of the obtained focal spot is 0.7 times of the working wavelength and is about 3 mm. Except for a small part of space which is close to the radiating plane of the SIW waveguide slot array, the spatial energy distribution outside the focal spot is lower than the energy at the focal spot by more than 15 dB.

The field intensity of an interference field formed by interference of reference waves and target waves is calculated through a holographic principle, whether a PIN diode above each gap is conducted or not is determined through time reversal according to a rectangular coordinate of a preset focus relative to the center of the coaxial feeder line, and whether the corresponding gap unit works or not is controlled. Specifically, in the present invention, the reference wave is TE propagated along the SIW rectangular waveguide excited by the coaxial feed structure₁₀And (3) mode electromagnetic waves, calculating according to the SIW constant amplitude power divider and the SIW extension waveguide to obtain the phase distribution of the reference waves on the metal plate on the upper surface of the waveguide, and screening based on a phase weighting formula:

A＝cos(∠ψ₀-∠(ψ_r)^*)

wherein psi₀For the phase of the reference wave at the slot radiating element, psi_rThe radiation phase of the slot radiation unit at the preset focus is obtained. In practical operation, to simplify the number of switch states and to take account of aperture efficiency, the weighting values for the unit switch states are taken as:

the corresponding phase difference ranges from-6 to + 6.

The antenna of the invention enables the radiation energy to be gathered at the focus as much as possible through near-field focusing, has very obvious focusing effect, simplifies the overall structure of the antenna through the SIW feed waveguide structure, and has the advantages of small volume and easy integration.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.