阅读说明：本技术 基于天线-滤波器-天线的带通频率选择表面结构 (Band-pass frequency selection surface structure based on antenna-filter-antenna ) 是由 李银 杜志敏 王世伟 刘柏杨 陈国文 胡熊敏 于 2020-12-14 设计创作，主要内容包括：本发明提供基于天线-滤波器-天线的带通频率选择表面结构,包含频率选择单元,频率选择单元由依次层叠的第一辐射贴片、第一介质板、第一金属地板、第二介质板、谐振层、第三介质板、第二金属地板、第四介质板和第二辐射贴片构成；第一金属地板上设置的第一缝隙的投影均落在第一辐射贴片上；第二金属地板上设置的第二缝隙的投影均落在第二辐射贴片上；谐振层由相互正交的第一微带和第二微带构成,第一缝隙落在谐振层的投影与第二缝隙落在谐振层的投影分居第一微带两侧；第一缝隙的长度方向、第二缝隙的长度方向均与第一微带的长度方向一致。该结构共产生四个传输极点和两个传输零点,具有稳定的准椭圆滤波响应和高选择性,角度稳定性好,剖面低。(The invention provides a band-pass frequency selection surface structure based on an antenna, a filter and an antenna, which comprises a frequency selection unit, wherein the frequency selection unit is formed by sequentially laminating a first radiation patch, a first dielectric plate, a first metal floor, a second dielectric plate, a resonance layer, a third dielectric plate, a second metal floor, a fourth dielectric plate and a second radiation patch; the projections of first gaps arranged on the first metal floor fall on the first radiation patches; projections of second gaps arranged on the second metal floor fall on the second radiation patches; the resonance layer is composed of a first microstrip and a second microstrip which are mutually orthogonal, and the projection of the first gap falling on the resonance layer and the projection of the second gap falling on the resonance layer are separated at two sides of the first microstrip; the length direction of the first slot and the length direction of the second slot are consistent with the length direction of the first microstrip. The structure generates four transmission poles and two transmission zeros, and has stable quasi-elliptic filtering response, high selectivity, good angle stability and low section.)

1. The band-pass frequency selection surface structure based on the antenna, the filter and the antenna is characterized by comprising a frequency selection unit, wherein the frequency selection unit is composed of a first radiation patch, a first dielectric plate, a first metal floor, a second dielectric plate, a resonance layer, a third dielectric plate, a second metal floor, a fourth dielectric plate and a second radiation patch which are sequentially stacked;

the first metal floor is provided with first gaps, and projections of the first gaps fall on the first radiation patches; a second gap is formed in the second metal floor, and the projections of the second gap fall on the second radiation patch;

the resonance layer is composed of a first microstrip and a second microstrip which are mutually orthogonal, and the projection of the first gap falling on the resonance layer and the projection of the second gap falling on the resonance layer are separated at two sides of the first microstrip; the length direction of the first slot and the length direction of the second slot are consistent with the length direction of the first microstrip.

2. The antenna-filter-antenna based band-pass frequency selective surface structure of claim 1, wherein the length direction of the first slot and the second slot are both parallel to the length direction of the first microstrip.

3. The antenna-filter-antenna based band-pass frequency selective surface structure of claim 2, wherein the first and second radiating patches are rectangular patches, and a projection of the first radiating patch falling on the resonant layer and a projection of the second radiating patch falling on the resonant layer are separated on both sides of the first microstrip.

4. The antenna-filter-antenna based band-pass frequency selective surface structure of claim 3, wherein the first radiating patch and the second radiating patch are each for forming a TM₀₁Mode or TM₁₀And the projection of the center of the first gap is coincided with the center of the first radiation patch, and the projection of the center of the second gap is coincided with the center of the second radiation patch.

5. The antenna-filter-antenna based bandpass frequency selective surface structure of claim 4, wherein the projection of the first slot onto the resonant layer is equidistant from the first microstrip and the projection of the second slot onto the resonant layer is equidistant from 0.1 to 0.5 center operating frequency wavelengths.

6. The antenna-filter-antenna based band-pass frequency selective surface structure of claim 5, wherein said first slot and said second slot are equal in length and are each 0.1-0.4 central operating frequency wavelengths; the widths of the first gap and the second gap are 0.01-0.03 central working frequency wavelength; the first radiation patch and the second radiation patch are the same in size, and the side length is 0.2-0.5 central working frequency wavelength.

7. The antenna-filter-antenna based band-pass frequency selective surface structure of claim 6, wherein a projection of the first slot center onto the resonance layer and a projection of the second slot center onto the resonance layer are both located on the second microstrip; a first branch and a second branch are further arranged at two ends of the first microstrip, and the total length of the first microstrip, the first branch and the second branch is 0.2-0.5 central working frequency wavelength; the length of the second microstrip is 0.2-0.5 central working frequency wavelength.

8. The antenna-filter-antenna based bandpass frequency selective surface structure of claim 7 wherein the center of the first microstrip coincides with the center of the second microstrip.

9. The antenna-filter-antenna based bandpass frequency selective surface structure of claim 8, wherein the first stub and the second stub are mirror symmetric about the second microstrip.

10. The antenna-filter-antenna based band-pass frequency selective surface structure according to any one of claims 1 to 9, wherein said frequency selective elements are provided in M × N number, respectively tiled on the same plane and spaced from each other by 0.4 to 0.8 central operating frequency wavelengths; the thickness of the first dielectric plate is 1/60-1/20 central working frequency wavelengths, and the dielectric constant is 2.0-4.0; the thickness of the second dielectric plate is 1/60-1/20 central working frequency wavelengths, and the dielectric constant is 2.0-4.0; the thickness of the third dielectric plate is 1/60-1/20 central working frequency wavelengths, and the dielectric constant is 2.0-4.0; the thickness of the fourth dielectric plate is 1/60-1/20 central working frequency wavelengths, and the dielectric constant is 2.0-4.0; the first dielectric plate, the second dielectric plate, the third dielectric plate and the fourth dielectric plate are all rectangular, and the projections of the centers of the first dielectric plate, the second dielectric plate, the third dielectric plate and the fourth dielectric plate on the resonance layer are all coincided with the center of the second microstrip; wherein M, N is a natural number, M is greater than or equal to 5, and N is greater than or equal to 5.

Technical Field

The invention relates to the technical field of frequency surface selection, in particular to a band-pass frequency selection surface structure based on an antenna-filter-antenna.

Background

A Frequency Selective Surface (FSS) is a two-dimensional periodic Surface structure that reflects or transmits electromagnetic waves. The conventional frequency selective surface has two types, namely a frequency selective surface formed by a slot type and a patch periodic unit. The patch type is periodically provided with the same metal units on the surface of the medium. The other is a slit type, which is a structure in which slits are periodically etched in a metal plate. When the FSS is in a resonance state, incident electromagnetic waves are totally reflected or totally transmitted, so that the FSS can be used as a space filter and can be widely applied to the aspects of electromagnetic interference resistance, electromagnetic compatibility, electric radiation resistance, antenna decoupling and the like. At present, the method for improving the frequency selective surface selectivity generally adopts a multilayer structure or a 3D structure, so that the section of the whole structure is thick, and the 3D structure needs to be assembled in a complex way after being processed.

According to investigation and understanding, the prior art that has been disclosed is as follows:

1) the invention patent application with the Chinese patent application number of 201710415782.9 discloses a frequency selective surface structure of an ultra-wide passband, and aims to improve the angle stability of the frequency selective surface. The structure consists of five layers, comprising: the chip comprises a first radiation patch layer, a first middle dielectric plate, a second radiation patch layer, a second middle dielectric plate and a third radiation patch layer. Five layers are pressed together in sequence. The first metal layer and the third metal layer structure unit are rectangles with the same length and width, the center of the unit is a rectangular patch with the same length and width smaller than the unit size, and quarter cross-shaped small iron sheets are uniformly distributed around the patch and connected with four corners of the unit. After the plane period is extended, a square patch array with crisscross patches at intervals is presented; and the second radiation patch layer has the same size as the rectangle, the center is a cross metal wire, the middle points of the units are connected with the rectangular radiation patches, and after plane extension, the grid array with the square patches at the middle points between the intersection points is presented. The frequency selective surface has the characteristic of ultra-wide pass band, can be freely combined with structures such as skins, shells, protective covers and the like with most thicknesses, and has high use value. But has the following disadvantages: the frequency selective surface structure is less selective for frequencies outside the passband.

2) The invention patent application with the Chinese patent application number of 201810577469.X discloses a high-angle stable frequency selection surface and a design method thereof, wherein the frequency selection surface comprises M × N frequency selection surface units which are periodically arranged, each frequency selection surface unit comprises a dielectric plate and a metal ring pair which is formed by two oppositely arranged open metal rings and arranged on the upper surface and the lower surface of the dielectric plate, the opening directions of the two metal rings on the surfaces are opposite, the first rectangular gaps of the two radiation patches are opposite in direction and are rotationally symmetrical with respect to the normal line of the dielectric plate at 180 degrees, the positions of the metal ring pair and the radiation patch pair on the same surface are correspondingly positioned at the position where the projection of the metal ring pair on the upper surface is rotated by 90 degrees, and the open ends of the two pairs of metal rings are correspondingly linked up and down through metal through holes, so that the structure of the selection surface unit is formed. The method can be applied to a plurality of scenes with strict requirements on the angular stability of the frequency selection surface, such as a reflector antenna. But has the following disadvantages: the frequency selective surface structure is less selective for frequencies outside the passband.

3) The invention patent application with chinese patent application number 201910331692.0 discloses a band-pass 3D frequency selective surface, aiming at improving the angular stability of a wide band-pass 3D frequency surface, comprising m × n resonance units: every resonance unit includes five layers of dielectric slabs and four layers of metal levels, the metal level includes four ladder loop configuration of upper dielectric slab upper surface and lower floor's dielectric slab lower surface, the square loop configuration that middle level dielectric slab upper and lower surface constitutes around dielectric slab four sides edge to and the inside two sets of 2 x 2 square loop configuration of square loop, the center of first group square loop configuration is in four diagonal positions of dielectric slab, the annular center of second group is on the mid point of adjacent first group cyclic annular center line, each ladder loop configuration of upper dielectric slab upper surface and lower floor's dielectric slab lower surface passes through the wire and corresponds the connection. The structure improves the angle stability while realizing the steep-falling edge passband, so that the structure can be applied to the aspects of communication and radar under the condition of large incident angle. But has the following disadvantages: the angular stability of the frequency selective surface structure is general and the overall structure profile is thick.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: a band-pass frequency selection surface structure which is easy to process, low in section, good in angle stability and high in selectivity is designed, and the defects that the out-of-band selectivity is poor, the structural section is thick and the like in the prior art are overcome.

In order to solve the technical problems, the invention adopts the technical scheme that:

the band-pass frequency selection surface structure based on the antenna, the filter and the antenna comprises a frequency selection unit, wherein the frequency selection unit is composed of a first radiation patch, a first dielectric plate, a first metal floor, a second dielectric plate, a resonance layer, a third dielectric plate, a second metal floor, a fourth dielectric plate and a second radiation patch which are sequentially stacked; the first metal floor is provided with first gaps, and projections of the first gaps fall on the first radiation patches; a second gap is formed in the second metal floor, and the projections of the second gap fall on the second radiation patch; the resonance layer is composed of a first microstrip and a second microstrip which are mutually orthogonal, and the projection of the first gap falling on the resonance layer and the projection of the second gap falling on the resonance layer are separated at two sides of the first microstrip; the length direction of the first slot and the length direction of the second slot are consistent with the length direction of the first microstrip.

Further, the length directions of the first slot and the second slot are both parallel to the length direction of the first microstrip.

Further, the first radiation patch and the second radiation patch are both rectangular patches, and a projection of the first radiation patch on the resonance layer and a projection of the second radiation patch on the resonance layer are separated on two sides of the first microstrip.

Further, the first radiation patch and the second radiation patch are both used for forming a TM₀₁Mode or TM₁₀And the projection of the center of the first gap is coincided with the center of the first radiation patch, and the projection of the center of the second gap is coincided with the center of the second radiation patch.

Further, the distance from the projection of the first slot on the resonance layer to the first microstrip is equal to the distance from the projection of the second slot on the resonance layer to the first microstrip, and the distances are all 0.1-0.5 central operating frequency wavelengths.

Furthermore, the lengths of the first gap and the second gap are equal and are both 0.1-0.4 central working frequency wavelengths; the widths of the first gap and the second gap are 0.01-0.03 central working frequency wavelength; the first radiation patch and the second radiation patch are the same in size, and the side length is 0.2-0.5 central working frequency wavelength.

Further, a projection of the center of the first slit on the resonance layer and a projection of the center of the second slit on the resonance layer are both located on the second microstrip; a first branch and a second branch are further arranged at two ends of the first microstrip, and the total length of the first microstrip, the first branch and the second branch is 0.2-0.5 central working frequency wavelength; the length of the second microstrip is 0.2-0.5 central working frequency wavelength.

Further, the center of the first microstrip coincides with the center of the second microstrip.

Further, the first branch and the second branch are mirror-symmetric with respect to the second microstrip.

Furthermore, M × N frequency selection units are arranged on the frequency selection unit, and are respectively paved on the same plane, and the distance between every two adjacent frequency selection units is 0.4-0.8 central working frequency wavelengths; the thickness of the first dielectric plate is 1/60-1/20 central working frequency wavelengths, and the dielectric constant is 2.0-4.0; the thickness of the second dielectric plate is 1/60-1/20 central working frequency wavelengths, and the dielectric constant is 2.0-4.0; the thickness of the third dielectric plate is 1/60-1/20 central working frequency wavelengths, and the dielectric constant is 2.0-4.0; the thickness of the fourth dielectric plate is 1/60-1/20 central working frequency wavelengths, and the dielectric constant is 2.0-4.0; the first dielectric plate, the second dielectric plate, the third dielectric plate and the fourth dielectric plate are all rectangular, and the projections of the centers of the first dielectric plate, the second dielectric plate, the third dielectric plate and the fourth dielectric plate on the resonance layer are all coincided with the center of the second microstrip; wherein M, N is a natural number, M is greater than or equal to 5, and N is greater than or equal to 5.

The invention has the beneficial effects that: the first radiating patch and the first gap are combined to form a receiving antenna/transmitting antenna, the second radiating patch and the second gap are combined to form a transmitting antenna/receiving antenna, and the first metal floor board containing the first gap, the resonance layer and the second metal floor board containing the second gap are combined to form a high-order filter, so that a high-order frequency selection surface is realized. The first radiating patch and the second radiating patch generate two transmission poles through resonance; when the first microstrip and the second microstrip which are mutually orthogonal resonate, even mode resonance and odd mode resonance are generated, and then two transmission poles are formed. The first microstrip also generates a low-frequency stop band transmission zero point, and the signals in two directions higher than the resonant frequency are mutually offset to form a high-frequency stop band transmission zero point. In summary, the band-pass frequency selection surface structure based on the antenna-filter-antenna of the present application generates four transmission poles and two transmission zeros altogether, has good stable quasi-elliptic filtering response and high selectivity, and has good angular stability. Because the multi-layer laminated structure is formed by overlapping, the structure is simple, the section is low, and the processing is easy.

Drawings

The detailed structure of the invention is described in detail below with reference to the accompanying drawings

Fig. 1 is a schematic cross-sectional view of a second microstrip of an antenna-filter-antenna based bandpass frequency selective surface structure of the present invention;

FIG. 2 is a schematic diagram showing a partial layer structure of the band-pass frequency selective surface structure based on antenna-filter-antenna according to the present invention;

FIG. 3 is a schematic diagram of a partial layer structure of the band-pass frequency selective surface structure based on antenna-filter-antenna of the present invention;

fig. 4 is a schematic diagram of a partial layered structure of the band-pass frequency selective surface structure based on the antenna-filter-antenna of the present invention;

fig. 5 is a schematic diagram of a partial layered structure of the band-pass frequency selective surface structure based on the antenna-filter-antenna of the present invention;

fig. 6 is a schematic diagram of a partial layered structure of the band-pass frequency selective surface structure based on the antenna-filter-antenna of the present invention;

FIG. 7 is a graph of an electromagnetic simulation of the S parameter performance of an antenna-filter-antenna based bandpass frequency selective surface structure of the present invention;

FIG. 8 is a simulation curve of reflection coefficients at different incident wave angles for an antenna-filter-antenna based bandpass frequency selective surface structure of the present invention;

FIG. 9 is a simulation curve of transmission coefficients at different incident wave angles for an antenna-filter-antenna based bandpass frequency selective surface structure of the present invention;

the antenna comprises a first radiating patch 1, a first dielectric plate 2, a first metal floor 3, a first gap 31, a second dielectric plate 4, a resonance layer 5, a first microstrip 51, a second microstrip 52, a first branch 53, a second branch 54, a third dielectric plate 6, a second metal floor 7, a second gap 71, a fourth dielectric plate 8 and a second radiating patch 9.

Detailed Description

The embodiments of the present invention according to the technical contents, structural features, and objects and effects thereof will be described in detail with reference to the accompanying drawings, wherein:

example 1

Referring to fig. 1 to 6, a band-pass frequency selection surface structure based on an antenna-filter-antenna includes a frequency selection unit, where the frequency selection unit is formed by sequentially stacking a first radiation patch 1, a first dielectric plate 2, a first metal floor 3, a second dielectric plate 4, a resonance layer 5, a third dielectric plate 6, a second metal floor 7, a fourth dielectric plate 8, and a second radiation patch 9; the first metal floor 3 is provided with first slits 31, and projections of the first slits 31 all fall on the first radiation patch 1, that is, projections of the first slits 31 falling on a plane where the first radiation patch 1 is located all fall on the first radiation patch 1; second slits 71 are arranged on the second metal floor 7, and projections of the second slits 71 all fall on the second radiation patches 9, that is, projections of the second slits 71 falling on a plane where the second radiation patches 9 are located all fall on the second radiation patches 9; the resonance layer 5 is composed of a first microstrip 51 and a second microstrip 52 which are orthogonal to each other, and the projection of the first slot 31 on the resonance layer 5 and the projection of the second slot 71 on the resonance layer 5 are separated on two sides of the first microstrip 51; the longitudinal direction of the first slot 31 and the longitudinal direction of the second slot 71 both coincide with the longitudinal direction of the first microstrip 51.

The first radiation patch 1 and the first slot 31 are combined to form a receiving antenna/transmitting antenna, the second radiation patch 9 and the second slot 71 are combined to form a transmitting antenna/receiving antenna, and the first metal floor 3 including the first slot 31, the resonance layer 5 and the second metal floor 7 including the second slot 71 are combined to form a high-order filter, thereby realizing a high-order frequency selective surface. The first radiation patch 1 and the second radiation patch 9 generate two transmission poles through resonance; when the first microstrip 51 and the second microstrip 52 orthogonal to each other resonate, even mode resonance and odd mode resonance are generated, and then two transmission poles are formed. The first microstrip 51 also generates a low-frequency stop band transmission zero, and the signals in two directions higher than the resonant frequency cancel each other out to form a high-frequency stop band transmission zero, both of which can improve the transmission characteristics. In summary, the band-pass frequency selection surface structure based on the antenna-filter-antenna of the present application generates four transmission poles and two transmission zeros altogether, and has good stable quasi-elliptic filtering response and high selectivity, and good angular stability. The multi-layer structure is formed by overlapping a plurality of layers of layered structures, and has simple structure, low section and easy processing.

Example 2

In the above configuration, the longitudinal directions of the first slot 31 and the second slot 71 are both parallel to the longitudinal direction of the first microstrip 51. Under the irradiation of the plane wave with the polarization direction perpendicular to the first gap 31/the second gap 71, when the incident angle is increased from 0 ° to 40 °, the frequency response is still very stable, and the angular stability is good.

Example 3

On the basis of the structure, the first radiation patch 1 and the second radiation patch 9 are rectangular patches, the first radiation patch 1 is located on the projection of the resonant layer 5, the second radiation patch 9 is located on the projection of the resonant layer 5, the two sides of the first microstrip 51 are separated, and the stability, the selectivity and the angle stability of the quasi-elliptic filtering response of the band-pass frequency selection surface structure based on the antenna-filter-antenna are further improved.

Example 4

On the basis of the above structure, the first radiation patch 1 and the second radiation patch 9 are both used for forming TM₀₁Mode or TM₁₀The projection of the center of the first gap 31 on the plane where the first radiation patch 1 is located coincides with the center of the first radiation patch 1, and the projection of the center of the second gap 71 on the plane where the second radiation patch 9 is located coincides with the center of the second radiation patch 9, so that the stability, selectivity and angle stability of quasi-elliptic filtering response of the antenna-filter-antenna based band-pass frequency selection surface structure are further improved. The first radiation patch 1 and the second radiation patch 9 generate two transmission poles through resonance, and form TM in three-dimensional space₀₁₀Mode(s).

Example 5

On the basis of the above structure, the distance from the projection of the first slot 31 on the resonance layer 5 to the first microstrip 51 is equal to the distance from the projection of the second slot 71 on the resonance layer 5 to the first microstrip 51, and the distances are all 0.1-0.5 central operating frequency wavelengths. The stability, selectivity and angle stability of the quasi-elliptic filtering response of the band-pass frequency selection surface structure based on the antenna-filter-antenna are further improved.

Example 6

On the basis of the structure, the lengths of the first gap 31 and the second gap 71 are equal, and the lengths are 0.1-0.4 central working frequency wavelengths; the widths of the first gap 31 and the second gap 71 are 0.01-0.03 central operating frequency wavelength; the first radiation patch 1 and the second radiation patch 9 have the same size, and the side length is 0.2-0.5 wavelength of central working frequency wavelength. The stability, selectivity and angle stability of the quasi-elliptic filtering response of the band-pass frequency selection surface structure based on the antenna-filter-antenna are further improved.

Example 7

On the basis of the above structure, the projection of the center of the first slot 31 on the resonance layer 5 and the projection of the center of the second slot 71 on the resonance layer 5 are both located on the second microstrip 52; a first branch 53 and a second branch 54 are further arranged at two ends of the first microstrip 51, and the total length of the first microstrip 51, the first branch 53 and the second branch 54 is 0.2-0.5 central working frequency wavelength; the length of the second microstrip 52 is 0.2-0.5 central operating frequency wavelength. The stability, selectivity and angle stability of the quasi-elliptic filtering response of the band-pass frequency selection surface structure based on the antenna-filter-antenna are further improved.

Example 8

On the basis of the structure, the center of the first microstrip 51 is superposed with the center of the second microstrip 52, so that the stability, selectivity and angle stability of the quasi-elliptic filtering response of the band-pass frequency selection surface structure based on the antenna-filter-antenna are further improved.

Example 9

On the basis of the above structure, the first branch 53 and the second branch 54 are mirror-symmetric with respect to the second microstrip 52, so as to further improve the stability, selectivity and angle stability of the quasi-elliptic filtering response of the band-pass frequency selection surface structure based on the antenna-filter-antenna.

Example 10

On the basis of the structure, the frequency selection units are provided with M × N frequency selection units which are respectively paved on the same plane, and the distance between every two adjacent frequency selection units is 0.4-0.8 central working frequency wavelength; the thickness of the first dielectric plate 2 is 1/60-1/20 central working frequency wavelengths, and the dielectric constant is 2.0-4.0; the thickness of the second dielectric plate 4 is 1/60-1/20 central working frequency wavelengths, and the dielectric constant is 2.0-4.0; the thickness of the third dielectric plate 6 is 1/60-1/20 central working frequency wavelengths, and the dielectric constant is 2.0-4.0; the thickness of the fourth dielectric plate 8 is 1/60-1/20 central working frequency wavelengths, and the dielectric constant is 2.0-4.0; the first dielectric plate 2, the second dielectric plate 4, the third dielectric plate 6 and the fourth dielectric plate 8 are all rectangular, and the projections of the centers of the four on the resonance layer 5 are all coincided with the center of the second microstrip 52; wherein M, N is a natural number, M is greater than or equal to 5, and N is greater than or equal to 5. The stability, selectivity and angle stability of the quasi-elliptic filtering response of the band-pass frequency selection surface structure based on the antenna-filter-antenna are further improved.

To further discuss the beneficial effects of the present invention, the following test examples are further illustrated:

test examples

A band-pass frequency selection surface structure based on an antenna, a filter and an antenna comprises a frequency selection unit, wherein the frequency selection unit is composed of a first radiation patch 1, a first dielectric plate 2, a first metal floor 3, a second dielectric plate 4, a resonance layer 5, a third dielectric plate 6, a second metal floor 7, a fourth dielectric plate 8 and a second radiation patch 9 which are sequentially stacked.

A first gap 31 is arranged on the first metal floor 3, and the projections of the first gap 31 fall on the first radiation patch 1; a second gap 71 is arranged on the second metal floor 7, and the projections of the second gap 71 fall on the second radiation patch 9; the resonance layer 5 is composed of a first microstrip 31 and a second microstrip 71 which are orthogonal to each other, and the projection of the first slot 31 on the resonance layer 5 and the projection of the second slot 71 on the resonance layer 5 are positioned on two sides of the first microstrip 51; the first slot 31 and the second slot 71 have both longitudinal directions parallel to the longitudinal direction of the first microstrip 51.

The first radiation patch 1 and the second radiation patch 9 are both used for forming TM₀₁Mode or TM₁₀Square metal of mouldAnd the projection of the first radiation patch 1 on the resonance layer 5 and the projection of the second radiation patch 9 on the resonance layer 5 are separated on two sides of the first microstrip 51. The projection of the center of the first slit 31 coincides with the center of the first radiation patch 1 and the projection of the center of the second slit 71 coincides with the center of the second radiation patch 9.

The distance from the projection of the first slot 31 on the resonance layer 5 to the first microstrip 51 is equal to the distance from the projection of the second slot 71 on the resonance layer 5 to the first microstrip 51, and both are 4.2 mm.

The lengths of the first gap 31 and the second gap 71 are equal and are both 4.2 mm; the first radiation patch 1 and the second radiation patch 9 have the same size, and the side length is 9.5 mm.

Further, a projection of the center of the first slot 31 on the resonance layer 5 and a projection of the center of the second slot 71 on the resonance layer 5 are both located on the second microstrip 52; a first branch 53 and a second branch 54 are further arranged at two ends of the first microstrip 51, and the total length of the first microstrip 51, the first branch 53 and the second branch 54 is 14.6 mm; the length of the second microstrip 52 is 10.9 mm. The center of the first microstrip 51 coincides with the center of the second microstrip 52. The first branch 53 and the second branch 54 are mirror symmetric with respect to the second microstrip 52.

Further, the frequency selection units are provided with 20 × 20 units, and the frequency selection units are respectively paved on the same plane. Along the direction perpendicular to the second microstrip 52, the distance between two adjacent frequency selection units is 15 mm; along the length direction of the second microstrip 52, the distance between two adjacent frequency selection units is 20 mm. The first dielectric plate 2, the second dielectric plate 4, the third dielectric plate 6 and the fourth dielectric plate 8 are all Rogers 4003C, and the dielectric constants are all 3.38; the first dielectric plate 2, the second dielectric plate 4, the third dielectric plate 6 and the fourth dielectric plate 8 are all rectangular, and the projections of the centers of the four on the resonance layer 5 coincide with the center of the second microstrip 52. The thickness of the first dielectric plate 2 and the fourth dielectric plate 8 is 1.524mm, and the thickness of the second dielectric plate 4 and the third dielectric plate 6 is 0.813 mm.

For the above structure, the electromagnetic simulation software CST is used to obtain the simulation result, which is detailed in the S parameter performance electromagnetic simulation curve of fig. 7, the reflection system number electromagnetic simulation curve of fig. 8, and the transmission coefficient simulation curve of fig. 9.

As can be seen from fig. 7, the structure of the present invention has a quasi-elliptical frequency response, where | S11| in fig. 7 is the return loss of the input port, | S21| is the forward transmission coefficient of the input port, and as can also be seen from fig. 7, | S11| has a value lower than-10 dB; the 3dB passband center frequency of the frequency selective surface is 7.07GHz, and two transmission zeros are generated at 6.71GHz and 7.59GHz, so that the roll-off characteristics of the low-frequency stop band and the high-frequency stop band are improved, and the frequency selective performance is improved.

As can be seen from fig. 8 and 9, when the incident angle is increased from 0 ° to 40 °, the present invention still has very stable frequency response, good angular stability, and increased practical application value.

In summary, the band-pass frequency selection surface structure based on the antenna, the filter and the antenna provided by the invention generates four transmission poles and two transmission zeros in total, and has good stable quasi-elliptic filter response, high selectivity and good angle stability. Because the multi-layer laminated structure is formed by overlapping, the structure is simple, the section is low, and the processing is easy.

The first … … and the second … … are only used for name differentiation and do not represent how different the importance and position of the two are.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes performed by the present specification and drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.