Broadband circularly polarized substrate integrated dielectric resonator filtering antenna

Abstract

The invention discloses a broadband circularly polarized substrate integrated dielectric resonator filter antenna, which is characterized in that structures such as an annular back cavity structure, an equivalent metal wall and a rectangular short patch act on a 3 * 3 rectangular dielectric sheet to form an annular back cavity substrate integrated dielectric resonator working in multiple modes; by inhibiting a cross polarization electric field and optimizing a main polarization electric field by the three, the gain fluctuation is effectively improved, the axial ratio bandwidth is broadened, the broadband circularly-polarized substrate integrated dielectric resonator filter antenna with stable gain is realized by combining the filtering effect of the E-type microstrip feed structure, and the substrate can be integrated and can give consideration to the profile and the size.

Description

Technical Field

[0001] The invention relates to a microwave communication device, in particular to a substrate integrated dielectric resonator filtering antenna. Background Art

[0002] Circularly polarized antennas have advantages in resisting multipath interference and avoiding polarization mismatch, and are widely used in satellite communications, intelligent transportation, radio frequency identification and other fields. With the increase in the rate and capacity of wireless systems, the bandwidth of circularly polarized antennas also needs to be improved to realize broadband circularly polarized antennas. At the same time, broadband dielectric resonator circularly polarized antennas realized with dielectrics have the characteristics of small size, low loss and high radiation efficiency. However, traditional circularly polarized dielectric resonator antennas are often complex in design, large in size, high in processing cost and difficult to integrate, resulting in a generally low operating frequency band. Therefore, substrate-integrated dielectric resonator antennas are needed to improve integrability. Furthermore, integrating the filtering function into the substrate-integrated dielectric resonator antenna to realize a broadband circularly polarized substrate-integrated dielectric resonator filter antenna can reduce the number of components and effectively reduce losses and costs. Therefore, the broadband circularly polarized substrate-integrated dielectric resonator filter antenna has great research significance and engineering value.

[0003] There are three main design methods for circularly polarized dielectric resonator filter antennas. The first method uses oblique annular slots to excite rectangular dielectric resonators to achieve circularly polarized radiation, and realizes the filtering function through a series microstrip filter, but there are problems such as narrow working bandwidth, large size, non-substrate integration and high profile. The second method uses cross-shaped slots to excite the orthogonal dielectric modes of cylindrical and rectangular column dielectric resonators to achieve circularly polarized radiation, or disturbs the orthogonal dielectric modes of elliptical dielectric resonances to achieve circularly polarized radiation, or uses metal strips to perturb the dielectric resonator to achieve circularly polarized radiation, and generates radiation zero points through comb branches, magnetic current ring loading or parallel resonators to achieve filtering functions, but there are still problems such as narrow working bandwidth and non-substrate integration. The third method uses an F-type microstrip feeder to excite the Y-shaped slot, and then couples and excites the stepped rectangular column dielectric resonator, uses the Y-shaped slot mode and the orthogonal dielectric mode of the dielectric resonance to achieve bandwidth widening of circularly polarized radiation, and uses the F-type microstrip feeder to generate filtering functions, but there are problems such as poor in-band gain stability, non-substrate integration and high profile. Therefore, it is necessary to propose a substrate-integrated circularly polarized dielectric resonator filter antenna with broadband working and stable gain, while taking both profile and size into consideration. Summary of the invention

[0004] Purpose of the invention: In view of the above-mentioned prior art, a broadband circularly polarized substrate integrated dielectric resonator filter antenna is proposed, which can simultaneously achieve wide working bandwidth, stable in-band gain and substrate integration, and can take into account both cross-section and size.

[0005] Technical solution: A broadband circularly polarized substrate integrated dielectric resonator filtering antenna, comprising: a first metal layer, an upper dielectric substrate, a second metal layer, an intermediate dielectric substrate, a metal stratum, a bottom dielectric substrate, and a bottom metal layer arranged in sequence from top to bottom; the first metal layer comprises a square ring-shaped metal sheet, and the inner sides of the square ring-shaped metal sheet are respectively provided with rectangular metal structures protruding inward, and the four protruding parts are distributed in rotational symmetry; a rectangular short patch and a rectangular long patch are distributed inside the square ring-shaped metal sheet; the upper dielectric substrate comprises a 3×3 rectangular dielectric sheet and a peripheral dielectric structure, and the peripheral dielectric structure is aligned with the square ring-shaped metal sheet up and down; there are dielectric-free areas between the 3×3 rectangular dielectric sheets and the peripheral dielectric structure, and the 3×3 rectangular dielectric sheets are connected to the peripheral dielectric structure into an integral dielectric structure through a plurality of internal dielectric connecting strips and a plurality of external dielectric connecting strips; the second metal layer comprises The first metal layer has a rectangular long patch 1 and a rectangular long patch 2 of the same size, and is aligned with the rectangular long patch 1 in the upper and lower directions; a step-shaped groove is etched on the metal stratum, and the step-shaped groove is composed of upper and lower transverse arms and vertical grooves connecting the upper and lower transverse arms; the step-shaped groove is directly opposite to five dielectric sheets in the 3×3 rectangular dielectric sheets; the bottom metal layer is an E-type metal structure; the metallized blind hole 1 is periodically arranged around the inner edge of the square ring-shaped metal sheet and connected to the metal stratum to form an annular back cavity structure; the metallized blind hole 2 connects the rectangular long patch 1 and the rectangular long patch 2 to form an equivalent metal wall; the first metal layer, the upper dielectric substrate, the second metal layer, the middle dielectric substrate, the metal stratum, the metallized blind hole 1 and the metallized blind hole 2 constitute an annular back cavity substrate integrated dielectric resonator as the radiator of the antenna; the bottom metal layer, the bottom dielectric substrate and the metal stratum constitute an E-type microstrip feeding structure.

[0006] Furthermore, in the upper dielectric substrate, the dielectric sheet located at the upper left corner of the 3×3 rectangular dielectric sheets is distributed below the rectangular short patch of the first metal layer and the right edges of the two overlap with each other; the dielectric sheet located in the center of the 3×3 rectangular dielectric sheets is distributed below the rectangular long patch of the first metal layer and the left edges of the two overlap with each other.

[0007] Furthermore, the E-shaped metal structure includes a metal strip, two T-shaped strips and a rectangular metal strip; wherein, the metal strip is arranged horizontally, and one end is located in the middle of one side of the antenna, and the rectangular metal strip connects the other end of the metal strip located in the center of the antenna; the two T-shaped strips are symmetrically arranged on both sides of the middle of the metal strip.

[0008] Furthermore, the transverse inner side length of the square ring-shaped metal sheet is 0.66λ 0 ~0.68λ 0 The longitudinal inner side length is between 0.62λ 0 ~0.64λ 0The width of the inwardly protruding rectangular metal structure in the longitudinal direction is 0.052λ 0 ~0.053λ 0 The length in the transverse direction is 0.382λ 0 ~0.42λ 0 between.

[0009] Furthermore, the width of the rectangular short patch in the lateral direction is 0.068λ 0 ~0.072λ 0 The length in the longitudinal direction is 0.087λ 0 ~0.089λ 0 The width of the rectangular long patch in the lateral direction is 0.056λ 0 ~0.058λ 0 The length in the longitudinal direction is between 0.14λ 0 ~0.16λ 0 between.

[0010] Furthermore, the length of the upper and lower transverse arms of the stepped groove is 0.22λ 0 ~0.24λ 0 The length of the longitudinal groove is between 0.32λ 0 ~0.34λ 0 between.

[0011] Beneficial effects: Existing circularly polarized dielectric resonator filter antennas have not achieved substrate integration, and there are problems such as too narrow working bandwidth or wide working bandwidth but poor gain stability within the band, and there are also problems such as high profile or large size. The present invention applies structures such as an annular back cavity structure, equivalent metal wall and rectangular short patch to 3×3 rectangular dielectric sheets to form a multi-mode annular back cavity substrate integrated dielectric resonator, and utilizes the suppression of the cross-polarization electric field and the optimization of the main polarization electric field by the three to effectively improve gain fluctuations and widen the axial ratio bandwidth. Combined with the filtering effect of the E-type microstrip feeding structure, a broadband circularly polarized substrate integrated dielectric resonator filter antenna with stable gain is realized, and the substrate can be integrated, which can take into account both profile and size.

[0012] Specifically, the 3×3 rectangular dielectric sheet is located in the center area of ​​the antenna, and is connected with five dielectric connecting strips inside, and is connected with the upper dielectric substrate through four external dielectric connecting strips to form an integral dielectric structure, which is easy to integrate, and works as a whole with the middle dielectric substrate and the metal ground with stepped grooves. Y-slot die and mode, providing the basis for broadband circular polarization work.

[0013] The metallized blind holes are periodically arranged around the inner edge of the top square ring metal sheet and connected to the metal layer to form a ring-shaped back cavity structure to suppress the y-direction slot mode and The right-hand circularly polarized electric field distribution generated during mode combination effectively solves the gain depression problem and broadens the axial ratio frequency range in the low-frequency region.

[0014] Metallized blind hole 2 is used to connect rectangular long patch 1 and rectangular long patch 2 to form an equivalent metal wall, which can suppress the right-hand circularly polarized electric field in the central patch area of ​​the 3×3 rectangular dielectric patch and optimize the left-hand circularly polarized electric field of the dielectric patch on its left side, so that the antenna gain remains smooth and stable, and the axial ratio in the high-frequency area is greatly improved.

[0015] The rectangular short patch can optimize the left-hand circularly polarized electric field in the patch area at the upper left corner of the 3×3 rectangular dielectric sheet, have a certain adjustment effect on the high-frequency axial ratio, and optimize the axial ratio bandwidth. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of a cross-sectional structure of an antenna;

[0017] Figure 2 is a schematic structural diagram of the first metal layer;

[0018] Figure 3 is a schematic diagram of the structure of the upper dielectric substrate;

[0019] Figure 4 is a schematic structural diagram of the second metal layer;

[0020] Figure 5 It is a schematic diagram of the structure of the metal stratum;

[0021] Figure 6 is a schematic diagram of the structure of the bottom metal layer;

[0022] Figure 7 For antenna |S 11 | and gain simulation results;

[0023] Figure 8 is the simulation result of the axial ratio of the antenna;

[0024] Fig. 9 is the simulation efficiency curve of the antenna;

[0025] Fig.10 is the simulated radiation pattern of the antenna at 9.4GHz;

[0026] Fig.11 is the simulated radiation pattern of the antenna at 10.4GHz;

[0027] Fig.12 This is the simulated radiation pattern of the antenna at 11.4 GHz. DETAILED DESCRIPTION

[0028] The present invention will be further explained below in conjunction with the accompanying drawings.

[0029] like Figure 1 As shown, a broadband circularly polarized substrate integrated dielectric resonator filter antenna includes a first metal layer 1, an upper dielectric substrate 2, a second metal layer 3, an intermediate dielectric substrate 4, a metal layer 5, a bottom dielectric substrate 6, and a bottom metal layer 7, which are arranged in sequence from top to bottom, and also include a plurality of metallized blind holes 8 and a plurality of metallized blind holes 9, wherein the dielectric constant of the upper dielectric substrate 2 is greater than the dielectric constants of the intermediate dielectric substrate 4 and the bottom dielectric substrate 6.

[0030] like Figure 2 As shown, the first metal layer 1 includes a square ring-shaped metal sheet 101, a rectangular short patch 102 and a rectangular long patch 103. The inner side edges of the square ring-shaped metal sheet 101 are respectively provided with rectangular metal structures protruding inward, and the four protruding parts are distributed in a rotationally symmetrical manner. The rectangular short patch 102 and the rectangular long patch 103 are distributed in the square ring-shaped metal sheet 101. Among them, the length of the inner side edge of the square ring-shaped metal sheet 101 in the horizontal direction (x axis) is 0.66λ. 0 ~0.68λ 0 The length of the inner side of the longitudinal direction (y axis) is 0.62λ 0 ~0.64λ 0 Between 0 is the free space wavelength corresponding to the center frequency; the width of the inwardly protruding rectangular metal structure in the y-axis direction is 0.052λ 0 ~0.053λ 0 The length in the x-axis direction is 0.382λ 0 ~0.42λ 0 The width of the rectangular short patch 102 in the x-axis direction is 0.068λ 0 ~0.072λ 0 The length in the y-axis direction is 0.087λ 0 ~0.089λ 0 The width of the rectangular long patch 103 in the x-axis direction is 0.056λ 0 ~0.058λ 0 The length in the y-axis direction is 0.14λ 0 ~0.16λ 0 between.

[0031] like Figure 3As shown, the upper dielectric substrate 2 includes a 3×3 rectangular dielectric sheet 201, a peripheral dielectric structure 202, five internal dielectric connecting strips 203 and four external dielectric connecting strips 204. Among them, the plane shape and size of the peripheral dielectric structure 202 are consistent with the square ring-shaped metal sheet 101 of the first metal layer 1, and are aligned up and down. There is a dielectric-free area, that is, air, between the 3×3 rectangular dielectric sheets 201 and between them and the peripheral dielectric structure 202. The internal dielectric connecting strip 203 and the four external dielectric connecting strips 204 are used to connect the 3×3 rectangular dielectric sheet 201 and the peripheral dielectric structure 202 into an integral dielectric structure, which is convenient for integration and keeps the antenna working normally. The dielectric sheet located in the upper left corner of the 3×3 rectangular dielectric sheet 201 is distributed under the rectangular short patch 102 of the first metal layer 1 and the right edges of the two overlap each other; the dielectric sheet located in the center of the 3×3 rectangular dielectric sheet 201 is distributed under the rectangular long patch 103 of the first metal layer 1 and the left edges of the two overlap each other.

[0032] like Figure 4 As shown, the second metal layer 3 includes a second rectangular long patch 301, which has the same size as the first rectangular long patch 103 of the first metal layer 1, and the two are aligned vertically.

[0033] like Figure 5 As shown, a stepped groove 501 is etched on the metal layer 5, and the length of the upper and lower lateral arms is 0.22λ 0 ~0.24λ 0 The length of the longitudinal groove is between 0.32λ 0 ~0.34λ 0 The stepped groove 501 faces the five dielectric sheets in the 3×3 rectangular dielectric sheet 201 .

[0034] like Figure 6 As shown, the bottom metal layer 7 is an E-shaped metal structure, including a metal strip 701, two T-shaped strips 702 and a rectangular metal strip 703. The metal strip 701 is arranged horizontally, and one end is located in the middle of one side of the antenna, and the rectangular metal strip 703 connects the other end of the metal strip 701 located in the center of the antenna; the two T-shaped strips 702 are symmetrically arranged on both sides of the middle of the metal strip 701.

[0035] like Figures 1 to 5 As shown, the metallized blind via 1 8 is periodically arranged around the inner edge of the square ring metal sheet 101 and connected to the metal layer 5, thereby forming a ring-shaped back cavity structure. The metallized blind via 2 9 is used to connect the rectangular long patch 1 103 and the rectangular long patch 2 301 to form an equivalent metal wall.

[0036] The first metal layer 1, the upper dielectric substrate 2, the second metal layer 3, the middle dielectric substrate 4, the metal layer 5, the metalized blind hole 1 8 and the metalized blind hole 2 9 constitute a ring-shaped back cavity substrate integrated dielectric resonator as the radiator of the antenna. The bottom metal layer 7, the bottom dielectric substrate 6 and the metal layer 5 constitute an E-type microstrip feeding structure.

[0037] For the proposed antenna, the signal is coupled to the stepped groove 501 of the metal layer 5 through the bottom E-type microstrip feeding structure, and further coupled to excite the annular back cavity substrate integrated dielectric resonator, forming a broadband circularly polarized radiation with stable gain and filtering effect under the action of the overall structure.

[0038] In this process, the 3×3 rectangular dielectric sheet 201 of the upper dielectric substrate 2, the middle dielectric substrate 4 and the metal layer 5 with the stepped groove 501 work as a whole. Y-slot die and mode, the four modes form a 90-degree phase difference between each other, forming left-hand circularly polarized radiation, but With y-direction slot die and y-direction slot die with When the modes are combined, a strong right-hand circularly polarized electric field distribution will be generated in some small areas, resulting in poor in-band axial ratio and gain, making it difficult to achieve broadband operation and gain stability. When the annular back cavity structure is introduced, the y-direction slot mode and The right-hand circularly polarized electric field distribution generated during mode combination effectively improves the gain depression problem and broadens the axial ratio frequency range in the low-frequency region. After the equivalent metal wall is added, the right-hand circularly polarized electric field in the central patch area of ​​the 3×3 rectangular dielectric sheet 201 can be effectively suppressed, and the left-hand circularly polarized electric field of the dielectric patch on its left side can be optimized, so that the antenna gain remains flat and stable, and the axial ratio in the high-frequency region is greatly improved. After the rectangular short patch 102 is added, the left-hand circularly polarized electric field in the patch area in the upper left corner of the 3×3 rectangular dielectric sheet 201 can be optimized, which has a certain adjustment effect on the high-frequency axial ratio and optimizes the axial ratio bandwidth. Therefore, the overall antenna can obtain a wider matching bandwidth and axial ratio bandwidth, and the gain is stable. The E-type microstrip feeding structure at the bottom can form a dual-frequency wave limiting effect, help the antenna achieve a filtering effect, and feed the dielectric resonator integrated in the annular back cavity substrate and the stepped slot 501. The overall structure can realize the integration of the substrate, and its radiation working mechanism can take into account the profile and size.

[0039] This embodiment uses a combination of RT6010 substrate and RO4003C substrate, and the overall antenna unit size is 0.63λ 0 ×0.67λ 0 ×0.11λ 0 . This embodiment |S 11 The simulated response of | and gain is as follows Figure 7As shown, the 10-dB matching frequency range of the antenna is 8.4 GHz to 12 GHz, that is, the relative bandwidth can reach 35.3%, the maximum gain within the band can reach 7.6 dBic, and the gain remains stable with a fluctuation range of less than 0.46 dB. At the same time, a radiation zero point appears at 6 GHz and 14 GHz respectively to realize the filtering function. Figure 8 The simulated axial ratio of the antenna in this embodiment has a 3 dB axial ratio frequency range of 9.1 GHz to 12.2 GHz, that is, the relative bandwidth can reach 29.4%, and the overlapping bandwidth with the 10-dB matching bandwidth can reach 27.38%. Fig. 9 is the efficiency response curve of the antenna, and its maximum efficiency can reach 96.7%. Fig.10 When the antenna of this embodiment is working, from the simulated radiation patterns at 9.4 GHz, 10.4 GHz, and 11.4 GHz, it can be seen that this embodiment is a left-hand circularly polarized antenna, and its half-power beamwidth in the phi=0° plane is 74.5°, 71.7°, and 59.5°, respectively, and its half-power beamwidth in the phi=90° plane is 68.7°, 66.3°, and 63.0°, respectively.

[0040] Compared with the existing designs, the circularly polarized dielectric resonator filter antenna proposed by the present invention has the advantages of being able to simultaneously achieve broadband operation, gain stability and substrate integration, and can take into account the profile or size.

[0041] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A broadband circularly polarized substrate integrated dielectric resonator filter antenna, characterized in that: include: A first metal layer (1), an upper dielectric substrate (2), a second metal layer (3), an intermediate dielectric substrate (4), a metal ground layer (5), a bottom dielectric substrate (6), and a bottom metal layer (7) are arranged in sequence from top to bottom; The first metal layer (1) comprises a square ring-shaped metal sheet (101), wherein the inner sides of the square ring-shaped metal sheet (101) are respectively provided with inwardly protruding rectangular metal structures, and the four protruding parts are distributed in a rotationally symmetrical manner; a rectangular short patch (102) and a rectangular long patch 1 (103) are distributed inside the square ring-shaped metal sheet (101); The upper dielectric substrate (2) comprises a 3×3 rectangular dielectric sheet (201) and a peripheral dielectric structure (202), and the peripheral dielectric structure (202) is aligned with the square ring-shaped metal sheet (101) in a vertical manner; there are dielectric-free regions between the 3×3 rectangular dielectric sheets (201) and between the 3×3 rectangular dielectric sheets (201) and the peripheral dielectric structure (202), and the 3×3 rectangular dielectric sheets (201) and the peripheral dielectric structure (202) are connected to form an integral dielectric structure via a plurality of internal dielectric connection strips (203) and a plurality of external dielectric connection strips (204); The second metal layer (3) comprises a rectangular long patch 2 (301) having the same size as the rectangular long patch 1 (103) of the first metal layer (1), and being aligned vertically with the rectangular long patch 1 (103); A stepped groove (501) is etched on the metal layer (5), and the stepped groove (501) is composed of upper and lower transverse arms and a vertical groove connecting the upper and lower transverse arms; the stepped groove (501) is directly opposite to five dielectric sheets in the 3×3 rectangular dielectric sheets (201); the bottom metal layer (7) is an E-type metal structure; Metallized blind holes 1 (8) are periodically arranged around the inner edge of the square ring-shaped metal sheet (101) and connected to the metal stratum (5) to form an annular back cavity structure; metallized blind holes 2 (9) connect the rectangular long patch 1 (103) and the rectangular long patch 2 (301) to form an equivalent metal wall; The first metal layer (1), the upper dielectric substrate (2), the second metal layer (3), the middle dielectric substrate (4), the metal layer (5), the first metalized blind hole (8) and the second metalized blind hole (9) constitute an annular back cavity substrate integrated dielectric resonator, which serves as a radiator of the antenna; the bottom metal layer (7) and the bottom dielectric substrate (6) and the metal layer (5) constitute an E-type microstrip feeding structure.

2. The broadband circularly polarized substrate integrated dielectric resonator filter antenna according to claim 1, characterized in that: In the upper dielectric substrate (2), the dielectric sheet located at the upper left corner of the 3×3 rectangular dielectric sheets (201) is distributed below the rectangular short patch (102) of the first metal layer (1), and the right edges of the two overlap with each other; and the dielectric sheet located in the center of the 3×3 rectangular dielectric sheets (201) is distributed below the rectangular long patch one (103) of the first metal layer (1), and the left edges of the two overlap with each other.

3. The broadband circularly polarized substrate integrated dielectric resonator filter antenna according to claim 1, characterized in that: The E-shaped metal structure comprises a metal strip (701), two T-shaped strips (702) and a rectangular metal strip (703); wherein the metal strip (701) is arranged horizontally, and one end is located in the middle of one side of the antenna, and the rectangular metal strip (703) is connected to the other end of the metal strip (701) located in the center of the antenna; and the two T-shaped strips (702) are symmetrically arranged on both sides of the middle of the metal strip (701).

4. The broadband circularly polarized substrate integrated dielectric resonator filter antenna according to any one of claims 1 to 3, characterized in that: The transverse inner side length of the square ring-shaped metal sheet (101) is between 0.66λ0 and 0.68λ0, and the longitudinal inner side length is between 0.62λ0 and 0.64λ0; the inwardly protruding rectangular metal structure has a width in the longitudinal direction of between 0.052λ0 and 0.053λ0, and a length in the transverse direction of between 0.382λ0 and 0.42λ0.

5. The broadband circularly polarized substrate integrated dielectric resonator filter antenna according to claim 4, characterized in that: The width of the rectangular short patch (102) in the transverse direction is between 0.068λ0 and 0.072λ0, and the length in the longitudinal direction is between 0.087λ0 and 0.089λ0; the width of the rectangular long patch 1 (103) in the transverse direction is between 0.056λ0 and 0.058λ0, and the length in the longitudinal direction is between 0.14λ0 and 0.16λ0.

6. The broadband circularly polarized substrate integrated dielectric resonator filter antenna according to claim 6, characterized in that: The lengths of the upper and lower transverse arms of the stepped groove (501) are between 0.22λ0 and 0.24λ0, and the length of the longitudinal vertical groove is between 0.32λ0 and 0.34λ0.

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