Broadband high-gain polarization conversion F-P resonant cavity antenna

Abstract

The application discloses a broadband high-gain polarization conversion F-P resonant cavity antenna, which comprises a feed antenna and a polarization conversion metasurface arranged above the feed antenna; the polarization conversion metasurface comprises: a first layer of metal patch which is composed of 25 metal patches in the shape of cross-shaped windmill structure, and a metal through hole is arranged on the left side and the upper side of the unit respectively to realize conversion from linear polarization to circular polarization; a second layer of metal patch is laid on the upper surface of a second layer of dielectric substrate and etched with a circular gap; a third layer of metal patch is composed of 25 square metal patches and used for receiving electromagnetic waves of the feed antenna; the feed antenna comprises: a fourth layer of metal patch which is composed of four square patches, a rectangular patch is arranged in the middle of the fourth layer of metal patch, and a metal through hole is arranged on the rectangular patch; a fifth layer of metal patch is laid on the upper surface of a fourth layer of dielectric substrate and etched with a circular gap; and a sixth layer of metal patch adopts a microstrip line to transmit energy; and the application has the advantages of simple structure, wide frequency band, wide axial ratio bandwidth, high gain and small volume.

Description

Technical Field

[0001] This invention relates to the field of circularly polarized antenna engineering technology, specifically to a broadband high-gain polarization conversion FP resonant cavity antenna. Background Technology

[0002] Fabry-Pero (FP) resonator antennas, compared to traditional microstrip arrays, offer advantages such as high gain, simple feeding mechanisms, and low manufacturing costs, attracting widespread attention in the antenna industry. FP resonator antennas have potential applications in current and next-generation wireless communication systems, sensor systems, radar, and satellite communications.

[0003] To meet the demands of increasingly complex wireless communication systems due to rapid development, antennas with wide bandwidth, high gain, and circularly polarized radiation characteristics are essential. In practical applications, wideband, high-gain circularly polarized antennas effectively address the limitations of narrow bandwidth and low gain that restrict the performance of wireless communication systems. Furthermore, circularly polarized antennas offer better interference immunity compared to linearly polarized antennas, enabling them to better cope with increasingly complex electromagnetic and natural environments.

[0004] In conclusion, there is an urgent need to conduct research on broadband high-gain polarization conversion FP resonant cavity antennas in future wireless communication systems. Summary of the Invention

[0005] The purpose of this invention is to provide a broadband high-gain circularly polarized FP resonant cavity antenna with a simple structure that is easy to implement, and to meet the requirements of wide communication bandwidth, wide circular polarization bandwidth, and high directional gain.

[0006] The technical solution to achieve the purpose of this invention is as follows: a broadband high-gain polarization-conversion FP resonant cavity antenna, comprising a feed antenna and a polarization-conversion metasurface, wherein the polarization-conversion metasurface covers the feed antenna; the polarization-conversion metasurface comprises, from top to bottom, a first layer of metal patch, a first layer of dielectric substrate, a second layer of metal patch, a second layer of dielectric substrate, and a third layer of metal patch, wherein; the feed antenna comprises, from top to bottom, a fourth layer of metal patch, a third layer of dielectric substrate, a fifth layer of metal patch, a fourth layer of dielectric substrate, and a sixth layer of metal patch, wherein;

[0007] The first layer of metal patch consists of 5×5 identical metal sheets, and the main body of each metal sheet is a cross-shaped windmill structure. A metal through hole is etched on the left and upper sides of each cross-shaped windmill metal sheet, penetrating the first layer of dielectric substrate and the second layer of dielectric substrate, connecting the first layer of metal patch and the third layer of metal patch. The two metal through holes realize the conversion from linear polarization to circular polarization.

[0008] The second metal patch is laid flat on the surface of the second dielectric substrate, and 50 identical circular slits are etched.

[0009] The second dielectric substrate is penetrated by 50 metal vias, connecting the first metal patch and the third metal patch;

[0010] The third metal patch is laid flat on the lower surface of the second dielectric substrate and consists of 5×5 identical square metal pieces.

[0011] The fourth metal patch consists of four identical metal sheets and one rectangular metal sheet, including a first square metal sheet located at the upper left corner, a second square metal sheet located at the upper right corner, a third square metal sheet located at the lower left corner, a fourth square metal sheet located at the lower right corner, and a first rectangular metal sheet located in the middle; the first rectangular metal sheet has a fifty-first metal via etched on it, which penetrates the third and fourth dielectric substrates and connects the fourth metal patch and the sixth metal patch;

[0012] The fifth metal patch is laid flat on the entire upper surface of the fourth dielectric substrate, and a fifty-first circular slit is etched.

[0013] The fourth dielectric substrate is penetrated by the fifty-first metal via, connecting the fourth metal patch and the sixth metal patch;

[0014] The sixth layer of metal patch is the microstrip transmission line of the feed antenna.

[0015] Furthermore, the 25 metal sheets of the first layer of metal patch are, from left to right and from top to bottom, the first metal sheet, the second metal sheet, the third metal sheet, the fourth metal sheet, the fifth metal sheet, the sixth metal sheet, the seventh metal sheet, the eighth metal sheet, the ninth metal sheet, the tenth metal sheet, the eleventh metal sheet, the twelfth metal sheet, the thirteenth metal sheet, the fourteenth metal sheet, the fifteenth metal sheet, the sixteenth metal sheet, the seventeenth metal sheet, the eighteenth metal sheet, the nineteenth metal sheet, the twentieth metal sheet, the twenty-first metal sheet, the twenty-second metal sheet, the twenty-third metal sheet, the twenty-fourth metal sheet, and the twenty-fifth metal sheet;

[0016] The metal through holes corresponding to the first to the twenty-fifth metal sheets are, in order, the first to the fiftieth metal through holes.

[0017] Furthermore, the first metal sheet body is composed of a second rectangular metal sheet and a third rectangular metal sheet. A fourth rectangular metal sheet and a fifth rectangular metal sheet are added to the upper right and lower left positions of the second rectangular metal sheet, respectively. A sixth rectangular metal sheet and a seventh rectangular metal sheet are added to the upper left and lower right positions of the third rectangular metal sheet, respectively. A first metal through hole is etched on the sixth rectangular metal sheet and a second metal through hole is etched on the fourth rectangular metal sheet.

[0018] The second to twenty-fifth metal sheets have the same structure as the first metal sheet.

[0019] Furthermore, the 50 circular slits of the second layer of metal patch correspond to 50 metal through holes, which are the first to the fiftieth circular slits respectively;

[0020] The radii of the first to fiftieth circular slits are greater than the radii of the first to fiftieth metal through holes, and their centers are at the same position.

[0021] Furthermore, the 25 square metal pieces of the third layer of metal patch are, from left to right and from top to bottom, sequentially named: first square metal piece, second square metal piece, third square metal piece, fourth square metal piece, fifth square metal piece, sixth square metal piece, seventh square metal piece, eighth square metal piece, ninth square metal piece, tenth square metal piece, eleventh square metal piece, twelfth square metal piece, thirteenth square metal piece, fourteenth square metal piece, fifteenth square metal piece, sixteenth square metal piece, seventeenth square metal piece, eighteenth square metal piece, nineteenth square metal piece, twentieth square metal piece, twenty-first square metal piece, twenty-second square metal piece, twenty-third square metal piece, twenty-fourth square metal piece, and twenty-fifth square metal piece.

[0022] The main body of the first square metal sheet is the fifth square metal sheet, with the first metal through hole and the second metal through hole etched on the left and top sides respectively;

[0023] The second to twenty-fifth square metal sheets have the same structure as the first square metal sheet.

[0024] Furthermore, the first, second, third, and fourth square metal sheets of the fourth layer of metal patches are all metal sheets with a side length of 3.5mm, and the distance from the midpoint of the four square metal sheets to the origin is equal.

[0025] Furthermore, the radius of the fifty-first circular slit in the fifth layer of metal patch is larger than the radius of the fifty-first metal through-hole, and the centers of the two are at the same position.

[0026] Furthermore, the sixth layer of metal patch uses an eighth rectangular metal sheet as a microstrip line to transmit energy. The length of the eighth rectangular metal sheet is 13.8 mm.

[0027] Furthermore, the height H between the polarization-conversion metasurface and the feed antenna satisfies the following equation:

[0028]

[0029] in λ is the phase difference between the reflection phase of the upper polarization conversion metasurface and the reflection phase of the lower feed antenna, λ is the free space wavelength at the operating frequency, and N is any integer.

[0030] Furthermore, the thickness of the first dielectric substrate is 1.57 mm, the thickness of the second dielectric substrate is 1.57 mm, the thickness of the third dielectric substrate is 0.508 mm, and the thickness of the fourth dielectric substrate is 0.508 mm. All dielectric substrates are made of Rogers RT5880 material.

[0031] Compared with the prior art, the present invention has the following significant advantages: (1) The polarization conversion metasurface is etched with 50 metal vias to change the current direction and achieve circular polarization characteristics. The structure is simple, easy to integrate, and the axial ratio bandwidth is widened; (2) A wider impedance bandwidth is obtained by using metal vias and circular slot vias for feeding; (3) Microstrip lines are used to transmit energy, and the feeding antenna structure is simple. Attached Figure Description

[0032] Figure 1a This is a side view of the broadband high-gain polarization conversion FP resonant cavity antenna of the present invention.

[0033] Figure 1b This is a top view of the first layer of metal patch of the broadband high-gain polarization conversion FP resonant cavity antenna of the present invention.

[0034] Figure 1c This is a top view of the first dielectric layer substrate of the broadband high-gain polarization conversion FP resonant cavity antenna of the present invention.

[0035] Figure 1d This is a top view of the second layer metal patch of the broadband high-gain polarization conversion FP resonant cavity antenna of the present invention.

[0036] Figure 1e This is a top view of the second dielectric substrate of the broadband high-gain polarization conversion FP resonant cavity antenna of the present invention.

[0037] Figure 1f This is a top view of the third layer metal patch of the broadband high-gain polarization conversion FP resonant cavity antenna of the present invention.

[0038] Figure 1g This is a top view of the fourth layer metal patch of the broadband high-gain polarization conversion FP resonant cavity antenna of the present invention.

[0039] Figure 1hThis is a top view of the third dielectric substrate of the broadband high-gain polarization conversion FP resonant cavity antenna of the present invention.

[0040] Figure 1i This is a top view of the fifth metal patch of the broadband high-gain polarization conversion FP resonant cavity antenna of the present invention.

[0041] Figure 1j This is a top view of the fourth dielectric substrate of the broadband high-gain polarization conversion FP resonant cavity antenna of the present invention.

[0042] Figure 1k This is a top view of the sixth layer metal patch of the broadband high-gain polarization conversion FP resonant cavity antenna of the present invention.

[0043] Figure 2 This invention relates to the S-type high-gain polarization conversion FP resonant cavity antenna. 11 Line graph.

[0044] Figure 3 This is a gain curve diagram of the broadband high-gain polarization conversion FP resonant cavity antenna of the present invention.

[0045] Figure 4 This is the axial ratio curve of the broadband high-gain polarization conversion FP resonant cavity antenna of the present invention.

[0046] Figure 5 This is the radiation pattern of the broadband high-gain polarization conversion FP resonant cavity antenna of the present invention in the xoz plane at 24 GHz.

[0047] Figure 6 This is the radiation pattern of the broadband high-gain polarization conversion FP resonant cavity antenna of the present invention in the yoz plane at 24 GHz. Detailed Implementation

[0048] This invention relates to a broadband high-gain polarization conversion FP resonant cavity antenna, which features wide bandwidth, wide axial ratio bandwidth, and high gain characteristics. The Fabry-Perot resonant cavity working principle simplifies the antenna structure and makes it easier to manufacture. The use of metal vias and circular slot vias for feeding gives the antenna a wider impedance bandwidth. The first layer of metal patch uses 50 metal vias to achieve circular polarization by changing the current direction.

[0049] Combination Figures 1a to 1kThis invention discloses a broadband high-gain polarization-conversion FP resonant cavity antenna, comprising a feed antenna and a polarization-conversion metasurface. The polarization-conversion metasurface covers the feed antenna and is used to realize the conversion of the antenna from linear polarization to circular polarization, while improving the gain and bandwidth of the feed antenna. The polarization-conversion metasurface comprises, from top to bottom, a first layer of metal patch 1, a first layer of dielectric substrate 2, a second layer of metal patch 3, a second layer of dielectric substrate 4, and a third layer of metal patch 5. The feed antenna comprises, from top to bottom, a fourth layer of metal patch 6, a third layer of dielectric substrate 7, a fifth layer of metal patch 8, a fourth layer of dielectric substrate 9, and a sixth layer of metal patch 10.

[0050] The first layer of metal patch 1 consists of 5×5 identical metal sheets, and the main body of each metal sheet is a cross-shaped windmill structure. A metal through hole is etched on the left and upper sides of each cross-shaped windmill metal sheet, which penetrates the first layer of dielectric substrate 2 and the second layer of dielectric substrate 4, and connects the first layer of metal patch 1 and the third layer of metal patch 5. The two metal through holes realize the conversion from linear polarization to circular polarization.

[0051] The second metal patch 3 is laid flat on the upper surface of the second dielectric substrate 4, and 50 circular slits of the same shape are etched.

[0052] The second dielectric substrate 4 is penetrated by 50 metal vias, connecting the first metal patch 1 and the third metal patch 5;

[0053] The third layer metal patch 5 is laid flat on the lower surface of the second layer dielectric substrate 4 and consists of 5×5 identical square metal pieces, used to receive electromagnetic waves from the feed antenna.

[0054] The fourth metal patch 6 consists of four identical metal pieces and one rectangular metal piece, including a first square metal piece 61 located at the upper left corner, a second square metal piece 62 located at the upper right corner, a third square metal piece 63 located at the lower left corner, a fourth square metal piece 64 located at the lower right corner, and a first rectangular metal piece 65 located in the middle; the first rectangular metal piece 65 has a fifty-first metal through hole 66 etched on it, which penetrates the third dielectric substrate 7 and the fourth dielectric substrate 9, connecting the fourth metal patch 6 and the sixth metal patch 10;

[0055] The fifth metal patch 8 is laid flat on the entire upper surface of the fourth dielectric substrate 9, and a fifty-first circular slit 81 is etched therein;

[0056] The fourth dielectric substrate 9 is penetrated by the fifty-first metal through-hole 66, connecting the fourth metal patch 6 and the sixth metal patch 10.

[0057] The sixth layer metal patch 10 is the microstrip transmission line of the feed antenna.

[0058] As a specific example, the first layer of metal patch 1 consists of 5×5 identical metal sheets, including a first metal sheet 11, a second metal sheet 12, a third metal sheet 13, a fourth metal sheet 14, a fifth metal sheet 15, a sixth metal sheet 16, a seventh metal sheet 17, an eighth metal sheet 18, a ninth metal sheet 19, a tenth metal sheet 110, an eleventh metal sheet 111, a twelfth metal sheet 112, a thirteenth metal sheet 113, a fourteenth metal sheet 114, a fifteenth metal sheet 115, a sixteenth metal sheet 116, and a seventeenth metal sheet. 117, 18th metal sheet, 118th metal sheet, 119th metal sheet, 120th metal sheet, 121st metal sheet, 122nd metal sheet, 123rd metal sheet, 124th metal sheet, 125th metal sheet; the main body of each metal sheet is a cross-shaped windmill structure; each cross-shaped windmill metal sheet has a metal through hole etched on its left and top sides, and 50 metal through holes penetrate the first dielectric substrate 2 and the second dielectric substrate 4, connecting the first metal patch 1 and the third metal patch 5;

[0059] The first dielectric substrate 2 is covered by first to fiftieth metal vias 107, 108, 121, 122, 131, 132, 141, 142, 151, 152, 161, 162, 171, 172, 181, 182, 191, 192, 1101, 1102, 1111, 1112, 1121, 1122, and 1131. 1132, 1141, 1142, 1151, 1152, 1161, 1162, 1171, 1172, 1181, 1182, 1191, 1192, 1201, 1202, 1211, 1212, 1221, 1222, 1231, 1232, 1241, 1242, 1251, 1252 penetrate;

[0060] The second layer of metal patch 3 is laid flat on the upper surface of the second layer dielectric substrate 4, and 50 circular slots of the same shape are etched thereon, namely the first to the fiftieth circular slots 31, 32, 33, 34, 35, 36, 37, 38, 39, 310, 311, 312, 313, 314, 315, 316, 317, 318, 319, 320, 321, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334, 335, 336, 337, 338, 339, 340, 341, 342, 343, 344, 345, 346, 347, 348, 349, 350;

[0061] The second dielectric substrate 4 is covered by the first to fiftieth metal vias 107, 108, 121, 122, 131, 132, 141, 142, 151, 152, 161, 162, 171, 172, 181, 182, 191, 192, 1101, 1102, 1111, 1112, 1121, 1122, 1131, 1132, and 1141. 1142, 1151, 1152, 1161, 1162, 1171, 1172, 1181, 1182, 1191, 1192, 1201, 1202, 1211, 1212, 1221, 1222, 1231, 1232, 1241, 1242, 1251, 1252 penetrate through and connect the first layer metal patch 1 and the third layer metal patch 5;

[0062] The third layer metal patch 5 is laid flat on the lower surface of the second layer dielectric substrate 4 and is composed of 5×5 identical square metal sheets, including the first square metal sheet 51, the second square metal sheet 52, the third square metal sheet 53, the fourth square metal sheet 54, the fifth square metal sheet 55, the sixth square metal sheet 56, the seventh square metal sheet 57, the eighth square metal sheet 58, the ninth square metal sheet 59, the tenth square metal sheet 510, the eleventh square metal sheet 511, the twelfth square metal sheet 512, the thirteenth square metal sheet 513, the fourteenth square metal sheet 514, the fifteenth square metal sheet 515, the sixteenth square metal sheet 516, the seventeenth square metal sheet 517, the eighteenth square metal sheet 518, the nineteenth square metal sheet 519, the twentieth square metal sheet 520, the twenty-first square metal sheet 521, the twenty-second square metal sheet 522, the twenty-third square metal sheet 523, the twenty-fourth square metal sheet 524, and the twenty-fifth square metal sheet 525.

[0063] The fourth metal patch 6 consists of four identical metal pieces and a rectangular metal piece, including a first square metal piece 61 located in the upper left corner, a second square metal piece 62 located in the upper right corner, a third square metal piece 63 located in the lower left corner, and a fourth square metal piece 64 located in the lower right corner; a first rectangular metal piece 65 is placed in the middle of these four pieces, and a fifty-first metal through-hole 66 is etched on the first rectangular metal piece. The metal through-hole penetrates the third dielectric substrate 7 and the fourth dielectric substrate 9, connecting the fourth metal patch 6 and the sixth metal patch 10.

[0064] The third dielectric substrate 7 is penetrated by the fifty-first metal through-hole 66;

[0065] The fifth metal patch 8 is laid flat on the entire upper surface of the fourth dielectric substrate 9, and a fifty-first circular slit 81 is etched therein;

[0066] The fourth dielectric substrate 9 is penetrated by the fifty-first metal through-hole 66, connecting the fourth metal patch 6 and the sixth metal patch 10.

[0067] The sixth layer metal patch 10 is the microstrip transmission line of the feed antenna.

[0068] As a specific example, the first metal sheet 11, the second metal sheet 12, the third metal sheet 13, the fourth metal sheet 14, the fifth metal sheet 15, the sixth metal sheet 16, the seventh metal sheet 17, the eighth metal sheet 18, the ninth metal sheet 19, the tenth metal sheet 110, the eleventh metal sheet 111, the twelfth metal sheet 112, the thirteenth metal sheet 113, the fourteenth metal sheet 114, the fifteenth metal sheet 115, the sixteenth metal sheet 116, the seventeenth metal sheet 117, the eighteenth metal sheet 118, the nineteenth metal sheet 119, the twentieth metal sheet 120, the twenty-first metal sheet 121, the twenty-second metal sheet 122, the twenty-third metal sheet 123, the twenty-fourth metal sheet 124, and the twenty-fifth metal sheet 125 have the same structure but different positions;

[0069] The main body of the first metal sheet 11 is composed of a second rectangular metal sheet 105 and a third rectangular metal sheet 106. A fourth rectangular metal sheet 102 and a fifth rectangular metal sheet 104 are added to the upper right and lower left positions of the second rectangular metal sheet 105, respectively. A sixth rectangular metal sheet 101 and a seventh rectangular metal sheet 103 are added to the upper left and lower right positions of the third rectangular metal sheet 106, respectively. A first metal through hole 107 is etched on the sixth rectangular metal sheet 101, and a second metal through hole 108 is etched on the fourth rectangular metal sheet 102.

[0070] As a specific example, the radii of the first to fiftieth circular gaps 31, 32, 33, 34, 35, 36, 37, 38, 39, 310, 311, 312, 313, 314, 315, 316, 317, 318, 319, 320, 321, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334, 335, 336, 337, 338, 339, 340, 341, 342, 343, 344, 345, 346, 347, 348, 349, and 350 of the second layer metal patch 3 are larger than the radii of the first to fiftieth metal through holes 107 and 1. The radii of the numbers 08, 121, 122, 131, 132, 141, 142, 151, 152, 161, 162, 171, 172, 181, 182, 191, 192, 1101, 1102, 1111, 1112, 1121, 1122, 1131, 1132, 1141, 1142, 1151, 1152, 1161, 1162, 1171, 1172, 1181, 1182, 1191, 1192, 1201, 1202, 1211, 1212, 1221, 1222, 1231, 1232, 1241, 1242, 1251, and 1252 are the same, and their centers are in the same location.

[0071] As a specific example, the three-layer metal patch 5 is composed of 5×5 identical metal sheets. The main body of the first square metal sheet 51 is the fifth square metal sheet 511, and the first metal through hole 107 and the second metal through hole 108 are respectively etched on its left and top sides.

[0072] The second to twenty-fifth square metal pieces 52, 32, 53, 54, 55, 56, 57, 58, 59, 510, 511, 512, 513, 514, 515, 516, 517, 518, 519, 520, 52, 522, 523, 524, and 525 have the same structure as the first square metal piece 51, but are located in different positions.

[0073] As a specific example, the first square metal piece 61 in the upper left corner, the second square metal piece 62 in the upper right corner, the third square metal piece 63 in the lower left corner, and the fourth square metal piece 64 in the lower right corner of the fourth layer metal patch 6 are all metal pieces with a side length of 3.5mm, and the distance from the midpoint of the four square metal pieces to the origin is equal.

[0074] As a specific example, the radius of the fifty-first circular gap 81 of the fifth layer metal patch 8 is greater than the radius of the fifty-first metal through hole 66, and the centers of the two are at the same position.

[0075] As a specific example, the second rectangular metal sheet 1011 of the sixth layer metal patch 10 has a length of 13.8 mm and serves as a microstrip line for energy transmission.

[0076] As a specific example, the height H between the polarization-conversion metasurface and the feed antenna satisfies the following equation:

[0077]

[0078] in λ is the phase difference between the reflection phase of the upper polarization conversion metasurface and the reflection phase of the lower feed antenna, λ is the free space wavelength at the operating frequency, N is any integer, and the final height H is 7mm after optimization.

[0079] As a specific example, the thickness of the first dielectric substrate 2 is 1.57 mm, the thickness of the second dielectric substrate 4 is 1.57 mm, the thickness of the third dielectric substrate 7 is 0.508 mm, and the thickness of the fourth dielectric substrate 9 is 0.508 mm. All dielectric substrates are made of Rogers RT5880 material.

[0080] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0081] Example

[0082] Combination Figures 1a to 1k The present invention provides a broadband high-gain polarization conversion FP resonant cavity antenna, comprising, from top to bottom, a first layer of metal patch 1, a first layer of dielectric substrate 2, a second layer of metal patch 3, a second layer of dielectric substrate 4, a third layer of metal patch 5, a fourth layer of metal patch 6, a third layer of dielectric substrate 7, a fifth layer of metal patch 8, a fourth layer of dielectric substrate 9, and a sixth layer of metal patch 10.

[0083] The first layer of metal patches 1 consists of 5×5 identical metal sheets, including a first metal sheet 11, a second metal sheet 12, a third metal sheet 13, a fourth metal sheet 14, a fifth metal sheet 15, a sixth metal sheet 16, a seventh metal sheet 17, an eighth metal sheet 18, a ninth metal sheet 19, a tenth metal sheet 110, an eleventh metal sheet 111, a twelfth metal sheet 112, a thirteenth metal sheet 113, a fourteenth metal sheet 114, a fifteenth metal sheet 115, a sixteenth metal sheet 116, and a seventeenth metal sheet 117. The eighteenth metal sheet 118, the nineteenth metal sheet 119, the twentieth metal sheet 120, the twenty-first metal sheet 121, the twenty-second metal sheet 122, the twenty-third metal sheet 123, the twenty-fourth metal sheet 124, and the twenty-fifth metal sheet 125; the main body of each metal sheet is a cross-shaped windmill structure; each cross-shaped windmill metal sheet has a metal through hole etched on its left and upper sides, and 50 metal through holes penetrate the first dielectric substrate 2 and the second dielectric substrate 4, connecting the first metal patch 1 and the third metal patch 5;

[0084] The first dielectric substrate 2 is covered by first to fiftieth metal vias 107, 108, 121, 122, 131, 132, 141, 142, 151, 152, 161, 162, 171, 172, 181, 182, 191, 192, 1101, 1102, 1111, 1112, 1121, 1122, and 1131. 1132, 1141, 1142, 1151, 1152, 1161, 1162, 1171, 1172, 1181, 1182, 1191, 1192, 1201, 1202, 1211, 1212, 1221, 1222, 1231, 1232, 1241, 1242, 1251, 1252 penetrate;

[0085] The second layer of metal patch 3 is laid flat on the upper surface of the second layer dielectric substrate 4, and 50 circular slots of the same shape are etched thereon, namely the first to the fiftieth circular slots 31, 32, 33, 34, 35, 36, 37, 38, 39, 310, 311, 312, 313, 314, 315, 316, 317, 318, 319, 320, 321, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334, 335, 336, 337, 338, 339, 340, 341, 342, 343, 344, 345, 346, 347, 348, 349, 350;

[0086] The second dielectric substrate 4 is covered by the first to fiftieth metal vias 107, 108, 121, 122, 131, 132, 141, 142, 151, 152, 161, 162, 171, 172, 181, 182, 191, 192, 1101, 1102, 1111, 1112, 1121, 1122, 1131, 1132, and 1141. 1142, 1151, 1152, 1161, 1162, 1171, 1172, 1181, 1182, 1191, 1192, 1201, 1202, 1211, 1212, 1221, 1222, 1231, 1232, 1241, 1242, 1251, 1252 penetrate through and connect the first layer metal patch 1 and the third layer metal patch 5;

[0087] The third layer metal patch 5 is laid flat on the lower surface of the second layer dielectric substrate 4 and is composed of 5×5 identical square metal sheets, including the first square metal sheet 51, the second square metal sheet 52, the third square metal sheet 53, the fourth square metal sheet 54, the fifth square metal sheet 55, the sixth square metal sheet 56, the seventh square metal sheet 57, the eighth square metal sheet 58, the ninth square metal sheet 59, the tenth square metal sheet 510, the eleventh square metal sheet 511, the twelfth square metal sheet 512, the thirteenth square metal sheet 513, the fourteenth square metal sheet 514, the fifteenth square metal sheet 515, the sixteenth square metal sheet 516, the seventeenth square metal sheet 517, the eighteenth square metal sheet 518, the nineteenth square metal sheet 519, the twentieth square metal sheet 520, the twenty-first square metal sheet 521, the twenty-second square metal sheet 522, the twenty-third square metal sheet 523, the twenty-fourth square metal sheet 524, and the twenty-fifth square metal sheet 525.

[0088] The fourth metal patch 6 consists of four identical metal pieces and a rectangular metal piece, including a first square metal piece 61 located in the upper left corner, a second square metal piece 62 located in the upper right corner, a third square metal piece 63 located in the lower left corner, and a fourth square metal piece 64 located in the lower right corner; a first rectangular metal piece 65 is placed in the middle of these four pieces, and a fifty-first metal through-hole 66 is etched on the first rectangular metal piece. The metal through-hole penetrates the third dielectric substrate 7 and the fourth dielectric substrate 9, connecting the fourth metal patch 6 and the sixth metal patch 10.

[0089] The third dielectric substrate 7 is penetrated by the fifty-first metal through-hole 66;

[0090] The fifth metal patch 8 is laid flat on the entire upper surface of the fourth dielectric substrate 9, and a fifty-first circular slit 81 is etched therein;

[0091] The fourth dielectric substrate 9 is penetrated by the fifty-first metal through-hole 66, connecting the fourth metal patch 6 and the sixth metal patch 10.

[0092] The sixth layer metal patch 10 is the microstrip transmission line of the feed antenna.

[0093] The first metal sheet 11, the second metal sheet 12, the third metal sheet 13, the fourth metal sheet 14, the fifth metal sheet 15, the sixth metal sheet 16, the seventh metal sheet 17, the eighth metal sheet 18, the ninth metal sheet 19, the tenth metal sheet 110, the eleventh metal sheet 111, the twelfth metal sheet 112, the thirteenth metal sheet 113, the fourteenth metal sheet 114, the fifteenth metal sheet 115, the sixteenth metal sheet 116, the seventeenth metal sheet 117, the eighteenth metal sheet 118, the nineteenth metal sheet 119, the twentieth metal sheet 120, the twenty-first metal sheet 121, the twenty-second metal sheet 122, the twenty-third metal sheet 123, the twenty-fourth metal sheet 124, and the twenty-fifth metal sheet 125 have the same structure but different positions;

[0094] The main body of the first metal sheet 11 is composed of a second rectangular metal sheet 105 and a third rectangular metal sheet 106. A fourth rectangular metal sheet 102 and a fifth rectangular metal sheet 104 are added to the upper right and lower left positions of the second rectangular metal sheet 105, respectively. A sixth rectangular metal sheet 101 and a seventh rectangular metal sheet 103 are added to the upper left and lower right positions of the third rectangular metal sheet 106, respectively. A first metal through hole 107 is etched on the sixth rectangular metal sheet 101, and a second metal through hole 108 is etched on the fourth rectangular metal sheet 102.

[0095] The radii of the first to fiftieth circular gaps 31, 32, 33, 34, 35, 36, 37, 38, 39, 310, 311, 312, 313, 314, 315, 316, 317, 318, 319, 320, 321, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334, 335, 336, 337, 338, 339, 340, 341, 342, 343, 344, 345, 346, 347, 348, 349, and 350 of the second layer metal patch 3 are larger than the radii of the first to fiftieth metal through holes 107, 108, and 12. The radii of the numbers 1, 122, 131, 132, 141, 142, 151, 152, 161, 162, 171, 172, 181, 182, 191, 192, 1101, 1102, 1111, 1112, 1121, 1122, 1131, 1132, 1141, 1142, 1151, 1152, 1161, 1162, 1171, 1172, 1181, 1182, 1191, 1192, 1201, 1202, 1211, 1212, 1221, 1222, 1231, 1232, 1241, 1242, 1251, and 1252 are the same, and their centers are in the same location.

[0096] The third layer of metal patch 5 is composed of 5×5 identical metal pieces. The main body of the first square metal piece 51 is the fifth square metal piece 511, with the first metal through hole 107 and the second metal through hole 108 etched on its left and top sides, respectively.

[0097] The second to twenty-fifth square metal pieces 52, 32, 53, 54, 55, 56, 57, 58, 59, 510, 511, 512, 513, 514, 515, 516, 517, 518, 519, 520, 52, 522, 523, 524, and 525 have the same structure as the first square metal piece 51, but are located in different positions.

[0098] The first square metal piece 61 in the upper left corner, the second square metal piece 62 in the upper right corner, the third square metal piece 63 in the lower left corner, and the fourth square metal piece 64 in the lower right corner of the fourth layer of metal patch 6 are all metal pieces with a side length of 3.5mm, and the distance from the midpoint of the four square metal pieces to the origin is equal.

[0099] The radius of the fifty-first circular gap 81 of the fifth layer metal patch 8 is greater than the radius of the fifty-first metal through hole 66, and the centers of the two are at the same position.

[0100] The second rectangular metal sheet 1011 of the sixth layer metal patch 10 has a length of 13.8 mm and serves as a microstrip line for energy transmission.

[0101] The design process of this invention is as follows:

[0102] (a) The thickness of the first dielectric substrate 2 is 1.57 mm and the dielectric constant is 2.2; the thickness of the second dielectric substrate 4 is 1.57 mm and the dielectric constant is 2.2; the thickness of the third dielectric substrate 7 is 0.508 mm and the dielectric constant is 2.2; and the thickness of the fourth dielectric substrate 9 is 0.508 mm and the dielectric constant is 2.2.

[0103] (ii) The first metal patch 1 and the third metal patch 5 change the current direction by etching 50 metal through holes, so that the antenna can achieve circular polarization performance.

[0104] (iii) The fifth layer of metal patch 8 is made to give the antenna broadband characteristics by using metal through holes 66 and circular slots 81 through holes;

[0105] Combination Figures 1a to 1k The broadband high-gain polarization conversion FP resonant cavity antenna of this invention uses Roger RT5880 as the material for the first dielectric substrate 2, with a dielectric constant ε. r =2.2, thickness is 1.57mm, size is 30mm×30mm×1.57mm, the material of the second dielectric substrate 4 is Roger RT5880, dielectric constant ε r =2.2, thickness is 1.57mm, size is 30mm×30mm×1.57mm; the material of the third dielectric substrate 7 is Roger RT5880, dielectric constant ε r =2.2, thickness is 0.508mm, size is 30mm×30mm×0.508mm, the material of the fourth dielectric substrate 9 is Roger RT5880, dielectric constant ε r =2.2, thickness is 0.508mm, size is 30mm×30mm×0.508mm; 50 through holes penetrating the first dielectric substrate 2 and the second dielectric substrate 4 have a diameter of 0.4mm, and the spacing between each pair of through holes in each row is 6mm; 50 circular slots on the second metal patch 3 have a diameter of 0.6mm; through holes 66 penetrating the third dielectric substrate 7 and the fourth dielectric substrate 9 have a diameter of 0.4mm, and circular slots on the fifth metal patch 8 have a diameter of 0.6mm.

[0106] Figure 2 This invention relates to the S-type high-gain polarization conversion FP resonant cavity antenna. 11 The curve shows that the operating frequency band of the broadband high-gain circularly polarized antenna array is 22.83~25.85GHz, the absolute bandwidth is 3.02GHz, and the relative bandwidth is 12.6%. This antenna has a wide operating frequency band.

[0107] Figure 3 This is a curve showing the gain of the broadband high-gain polarization conversion FP resonant cavity antenna of the present invention as a function of frequency. The peak gain is 15.05 dBi, which is higher than that of a single circularly polarized antenna element.

[0108] Figure 4 This is the axial ratio curve of the broadband high-gain polarization conversion FP resonant cavity antenna of the present invention. The axial ratio bandwidth of the broadband high-gain circular polarization antenna array is 22.88~24.13GHz, the absolute axial ratio bandwidth is 1.25GHz, and the relative axial ratio bandwidth is 5.2%.

[0109] Figure 5 This invention relates to the radiation pattern of the broadband high-gain polarization conversion FP resonant cavity antenna at 24GHz on the xoz plane. The radiation pattern of the broadband high-gain polarization conversion FP resonant cavity antenna is stable, with cross-polarization less than -15dBic and back lobe radiation less than -16dBic.

[0110] Figure 6 This invention relates to the yoz plane radiation pattern of the broadband high-gain polarization conversion FP resonant cavity antenna at 24GHz. The pattern of the broadband high-gain polarization conversion FP resonant cavity antenna is stable, with cross-polarization less than -10dBic and back lobe radiation less than -16dBic.

[0111] In summary, the broadband high-gain polarization conversion FP resonant cavity antenna of the present invention has a wide bandwidth and axial ratio bandwidth, and has high gain within the operating frequency band, stable radiation pattern, low cross-polarization level, simple structure, and is easy to fabricate and implement.

Claims

1. A broadband high-gain polarization-conversion FP resonant cavity antenna, characterized in that, The system includes a feed antenna and a polarization conversion metasurface, with the polarization conversion metasurface covering the feed antenna. The polarization conversion metasurface includes a first layer of metal patch (1), a first layer of dielectric substrate (2), a second layer of metal patch (3), a second layer of dielectric substrate (4), and a third layer of metal patch (5) arranged sequentially from top to bottom. The feed antenna includes a fourth layer of metal patch (6), a third layer of dielectric substrate (7), a fifth layer of metal patch (8), a fourth layer of dielectric substrate (9), and a sixth layer of metal patch (10) arranged sequentially from top to bottom. The first layer of metal patch (1) consists of 5×5 identical metal sheets, and the main body of each metal sheet is a cross-shaped windmill structure; a metal through hole is etched on the left and upper sides of each cross-shaped windmill metal sheet, which penetrates the first layer of dielectric substrate (2) and the second layer of dielectric substrate (4) and connects the first layer of metal patch (1) and the third layer of metal patch (5). The two metal through holes realize the conversion from linear polarization to circular polarization. The second metal patch (3) is laid flat on the upper surface of the second dielectric substrate (4) and 50 circular slits of the same shape are etched. The second dielectric substrate (4) is penetrated by 50 metal through holes, connecting the first metal patch (1) and the third metal patch (5); The third layer metal patch (5) is laid flat on the lower surface of the second layer dielectric substrate (4) and consists of 5×5 identical square metal pieces, used to receive electromagnetic waves from the feed antenna; The fourth metal patch (6) consists of four identical metal pieces and a rectangular metal piece, including a first square metal piece (61) located in the upper left corner, a second square metal piece (62) located in the upper right corner, a third square metal piece (63) located in the lower left corner, a fourth square metal piece (64) located in the lower right corner, and a first rectangular metal piece (65) located in the middle; the first rectangular metal piece (65) has a fifty-first metal through hole (66) etched on it, which penetrates the third dielectric substrate (7) and the fourth dielectric substrate (9) and connects the fourth metal patch (6) and the sixth metal patch (10); The fifth metal patch (8) is laid flat on the entire upper surface of the fourth dielectric substrate (9) and the fifty-first circular slit (81) is etched. The fourth dielectric substrate (9) is penetrated by the fifty-first metal through-hole (66), connecting the fourth metal patch (6) and the sixth metal patch (10); The sixth layer metal patch (10) is the microstrip transmission line of the feed antenna.

2. The broadband high-gain polarization conversion FP resonant cavity antenna according to claim 1, characterized in that, The 25 metal pieces of the first layer of metal patch (1) are, from left to right and from top to bottom, the first metal piece (11), the second metal piece (12), the third metal piece (13), the fourth metal piece (14), the fifth metal piece (15), the sixth metal piece (16), the seventh metal piece (17), the eighth metal piece (18), the ninth metal piece (19), the tenth metal piece (110), the eleventh metal piece (111), the twelfth metal piece (112), the thirteenth metal piece (113), the fourteenth metal piece (114), the fifteenth metal piece (115), the sixteenth metal piece (116), the seventeenth metal piece (117), the eighteenth metal piece (118), the nineteenth metal piece (119), the twentieth metal piece (120), the twenty-first metal piece (121), the twenty-second metal piece (122), the twenty-third metal piece (123), the twenty-fourth metal piece (124), and the twenty-fifth metal piece (125). The metal through holes corresponding to the first metal sheet (11) to the twenty-fifth metal sheet (125) are, in order, the first to the fiftieth metal through holes (107, 108, 121, 122, 131, 132, 141, 142, 151, 152, 161, 162, 171, 172, 181, 182, 191, 192, 1101, 1102, 1111, 1112, 11 21, 1122, 1131, 1132, 1141, 1142, 1151, 1152, 1161, 1162, 1171, 1172, 1181, 1182, 1191, 1192, 1201, 1202, 1211, 1212, 1221, 1222, 1231, 1232, 1241, 1242, 1251, 1252).

3. The broadband high-gain polarization conversion FP resonant cavity antenna according to claim 2, characterized in that, The first metal sheet (11) is mainly composed of a second rectangular metal sheet (105) and a third rectangular metal sheet (106). A fourth rectangular metal sheet (102) and a fifth rectangular metal sheet (104) are added to the upper right and lower left positions of the second rectangular metal sheet (105), respectively. A sixth rectangular metal sheet (101) and a seventh rectangular metal sheet (103) are added to the upper left and lower right positions of the third rectangular metal sheet (106), respectively. A first metal through hole (107) is etched on the sixth rectangular metal sheet (101), and a second metal through hole (108) is etched on the fourth rectangular metal sheet (102). The second to twenty-fifth metal sheets (12, 13, 14, 15, 16, 17, 18, 19, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125) have the same structure as the first metal sheet (11).

4. The broadband high-gain polarization conversion FP resonant cavity antenna according to claim 3, characterized in that, The 50 circular slits of the second layer of metal patch (3) correspond to 50 metal through holes, namely the first to the fiftieth circular slits (31, 32, 33, 34, 35, 36, 37, 38, 39, 310, 311, 312, 313, 314, 315, 316, 317, 318, 319, 320, 321, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334, 335, 336, 337, 338, 339, 340, 341, 342, 343, 344, 345, 346, 347, 348, 349, 350); The radii of the first to fiftieth circular slits are greater than the radii of the first to fiftieth metal through holes, and their centers are at the same position.

5. The broadband high-gain polarization conversion FP resonant cavity antenna according to claim 3, characterized in that, The 25 square metal pieces of the third layer metal patch (5) are arranged from left to right and from top to bottom as follows: first square metal piece (51), second square metal piece (52), third square metal piece (53), fourth square metal piece (54), fifth square metal piece (55), sixth square metal piece (56), seventh square metal piece (57), eighth square metal piece (58), ninth square metal piece (59), tenth square metal piece (510), eleventh square metal piece (511), twelfth square metal piece (512), and... Thirteen square metal sheet (513), fourteenth square metal sheet (514), fifteenth square metal sheet (515), sixteenth square metal sheet (516), seventeenth square metal sheet (517), eighteenth square metal sheet (518), nineteenth square metal sheet (519), twentieth square metal sheet (520), twenty-first square metal sheet (521), twenty-second square metal sheet (522), twenty-third square metal sheet (523), twenty-fourth square metal sheet (524), twenty-fifth square metal sheet (525); The main body of the first square metal sheet (51) is the fifth square metal sheet (511), with the first metal through hole (107) and the second metal through hole (108) etched on the left and top sides respectively; The second to twenty-fifth square metal pieces (52, 53, 54, 55, 56, 57, 58, 59, 510, 511, 512, 513, 514, 515, 516, 517, 518, 519, 520, 521, 522, 523, 524, 525) have the same structure as the first square metal piece (51).

6. The broadband high-gain polarization conversion FP resonant cavity antenna according to claim 1, characterized in that, The first square metal sheet (61), the second square metal sheet (62), the third square metal sheet (63), and the fourth square metal sheet (64) of the fourth layer of metal patches (6) are all metal sheets with a side length of 3.5mm, and the distance from the midpoint of the four square metal sheets to the origin is equal.

7. The broadband high-gain polarization conversion FP resonant cavity antenna according to claim 1, characterized in that, The radius of the fifty-first circular slit (81) of the fifth layer metal patch (8) is greater than the radius of the fifty-first metal through hole (66), and the centers of the two are at the same position.

8. The broadband high-gain polarization conversion FP resonant cavity antenna according to claim 6, characterized in that, The sixth layer metal patch (10) uses the eighth rectangular metal sheet (1011) as a microstrip line to transmit energy. The length of the eighth rectangular metal sheet (1011) is 13.8 mm.

9. The broadband high-gain polarization conversion FP resonant cavity antenna according to claim 1, characterized in that, The height H between the polarization conversion metasurface and the feed antenna satisfies the following equation: in λ is the phase difference between the reflection phase of the upper polarization conversion metasurface and the reflection phase of the lower feed antenna, λ is the free space wavelength at the operating frequency, and N is any integer.

10. The broadband high-gain polarization conversion FP resonant cavity antenna according to any one of claims 1 to 9, characterized in that, The first dielectric substrate (2) has a thickness of 1.57 mm, the second dielectric substrate (4) has a thickness of 1.57 mm, the third dielectric substrate (7) has a thickness of 0.508 mm, and the fourth dielectric substrate (9) has a thickness of 0.508 mm. All dielectric substrates are made of Rogers RT5880.

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