CN210692750U

CN210692750U - Ka-band dual-polarized antenna unit structure based on resonant cavity radiation

Info

Publication number: CN210692750U
Application number: CN201922341713.5U
Authority: CN
Inventors: 刘锦霖; 何仲夏; 陈国胜; 梁稳
Original assignee: Shengweilun Shenzhen Communication Technology Co Ltd
Current assignee: Shengweilun Shenzhen Communication Technology Co Ltd
Priority date: 2019-12-23
Filing date: 2019-12-23
Publication date: 2020-06-05
Anticipated expiration: 2029-12-23

Abstract

The utility model provides a Ka wave band dual polarized antenna unit structure based on resonant cavity radiation, include: the dual-polarized antenna comprises a vertical polarization feed waveguide, a horizontal polarization feed waveguide, a coupling gap, a resonant cavity and a radiation gap, wherein the vertical feed waveguide and the horizontal feed waveguide enable electromagnetic waves to form constrained electromagnetic waves, the electromagnetic waves are coupled at the coupling gap and further coupled to the radiation gap through the coupling gap, and the resonant cavity, the vertical polarization feed waveguide and the horizontal polarization feed waveguide realize the dual-polarized antenna through orthogonal feed. The utility model discloses introduce the radiation of resonant cavity in dual polarization antenna structure, can reduce the structure complexity of antenna, improve the performance of antenna, resonant cavity's introduction has reduced one-level feed network simultaneously, has reduced the whole loss of feeder, has guaranteed the whole bandwidth of array simultaneously. The dual polarization is realized, and the dual polarization antenna has the advantages of small transmission loss, high return loss, wide working bandwidth, easiness in loading and unloading, good consistency and convenience in processing.

Description

Ka-band dual-polarized antenna unit structure based on resonant cavity radiation

Technical Field

The invention belongs to the field of antennas, and particularly relates to an improved structure of a dual-polarized antenna.

Background

In the field of communications, a Ka band is a part of a microwave band of an electromagnetic spectrum, a frequency range of the Ka band is 26.5 to 40GHz, and in millimeter wave band applications of the Ka band above 20GHz, because the gain of an antenna unit is limited, in order to obtain higher gain or meet the requirements of a specific directional diagram, a form of array of the antenna unit is often adopted. However, the number of the antenna units is increased, and the feed network of the antenna is also increased correspondingly, so that the antenna has a complex structure and performance is reduced.

Chinese patent application No. 2019104472409 discloses a Ka-band standing wave type series-fed microstrip linear array antenna, an area array antenna and a manufacturing method, wherein the microstrip linear array antenna comprises a dielectric substrate, a ground layer, a main feeder, a feeder and a series-fed microstrip linear array, the main feeder and the series-fed microstrip linear array are both connected with the upper surface of the dielectric substrate, and the ground layer is connected with the lower surface of the dielectric substrate; the series-fed microstrip linear array comprises a first impedance transformation matcher and a plurality of array elements. The microstrip planar array antenna comprises a dielectric substrate, a ground layer, a main feeder, a plurality of second impedance transformation matchers and a plurality of series-fed microstrip linear arrays. The main feeder line, the plurality of second impedance transformation matchers and the plurality of series feed microstrip linear arrays are all connected with the upper surface of the dielectric substrate, and the ground layer is connected with the lower surface of the dielectric substrate; one end of the series-fed microstrip linear array is open-circuited, and the other end of the series-fed microstrip linear array is connected with the main feeder line through a second impedance transformation matcher. And the incident wave and the reflected wave on the main feed line are superposed to realize standing wave transmission. The structure of the structure is complex, and certain special functions of the dual-polarized antenna cannot be realized.

Chinese patent application No. 2016102443605 discloses a Ka-band single circularly polarized antenna, wherein a circular polarizer comprises three layers, the upper two layers are microstrip patches printed on a dielectric substrate, and the third layer is a low-frequency circularly polarized back cavity; the circular polarizer is coupled and fed by the coupling cavity below the circular polarizer. The technical scheme is only to realize a single polarized antenna, but can not realize a dual polarized antenna.

Therefore, there is a need for a dual polarized antenna element structure, and in particular, a Ka-band dual polarized antenna element based on resonant cavity radiation.

Disclosure of Invention

In order to solve the problem of the dual-polarized antenna unit, the invention provides a Ka-band dual-polarized antenna unit based on resonant cavity radiation, which adopts the following technical scheme:

a structure of a Ka-band dual polarized antenna element based on resonant cavity radiation, comprising: the dual-polarized antenna comprises a vertical polarization feed waveguide, a horizontal polarization feed waveguide, a coupling gap, a resonant cavity and a radiation gap, wherein the vertical feed waveguide and the horizontal feed waveguide enable electromagnetic waves to form constrained electromagnetic waves, the electromagnetic waves are coupled at the coupling gap and further coupled to the radiation gap through the coupling gap, and the resonant cavity, the vertical polarization feed waveguide and the horizontal polarization feed waveguide realize the dual-polarized antenna through orthogonal feed.

Further, the resonant cavity can also be an air back cavity.

Furthermore, the radiation gap can be any one of a rectangle, an ellipse, a T shape, a cross shape and a dumbbell shape.

Furthermore, the coupling gap can be any one of a rectangle, an ellipse, a cross and a dumbbell.

Furthermore, the feed waveguide can be a mold cavity with closed periphery, and can also be periodically slotted.

Furthermore, the resonant cavity can be a cavity with closed periphery or can be periodically slotted.

The invention introduces the resonant cavity radiation in the dual-polarized antenna structure, can reduce the structural complexity of the antenna and improve the performance of the antenna, reduces the primary feed network by introducing the resonant cavity, reduces the integral loss of the feeder line, and ensures the integral bandwidth of the array. The dual polarization is realized, and the dual polarization antenna has the advantages of small transmission loss, high return loss, wider working bandwidth, easiness in loading and unloading, good consistency and convenience in processing.

Drawings

FIG. 1: the invention discloses an explosion diagram of a dual-polarized antenna unit structure.

FIG. 2: and distributing the magnetic field in the cavity of the dual-polarized antenna unit.

FIG. 3: and the electric field distribution diagram of the radiation slot of the dual-polarized antenna unit.

FIG. 4A: the antenna horizontal polarization pattern at the center frequency of 35 GHz.

FIG. 4B: the antenna vertical polarization pattern at a center frequency of 35 GHz.

FIG. 5: and (4) port return loss of the dual-polarized antenna unit after simulation optimization.

FIG. 6: a second embodiment of the dual polarized antenna element structure of the present invention is illustrated.

FIG. 7: fig. 1 is a cross-sectional view of a dual polarized antenna element structure.

Detailed Description

The reference numbers illustrate: 101: a vertical feed waveguide.

102: a coupling slot.

103: a horizontally polarized feed waveguide entrance.

104: a horizontally polarized feed waveguide cavity.

105: a first resonant cavity.

106: a first radiation slit.

107: a second radiation slot.

108: a second resonant cavity.

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, and while the invention will be described in connection with the preferred embodiments, it will be understood by those skilled in the art that these embodiments are not intended to limit the invention to these embodiments, but on the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details.

In a large-scale antenna array, the influence of coupling between different elements of the antenna on the antenna performance is very important, and the mutual coupling of adjacent elements can directly influence the matching bandwidth and radiation characteristics of the elements. Referring to fig. 1, an exploded view of a dual-polarized antenna unit structure of the present invention is shown, the dual-polarized antenna unit is a 2 × 2 antenna array structure, and includes, in order from top to bottom, a first radiation slot 106, a first resonant cavity 105, a horizontally polarized feed waveguide cavity 104, a horizontally polarized feed waveguide inlet 103, a coupling slot 102, and a vertically polarized feed waveguide 101.

The first resonant cavity 105 may also be an air cavity, and the conductor may be a metal structure, so as to achieve better antenna gain, and in particular, the shapes of the components shown in fig. 1 are only used for reference, and those skilled in the art may make various changes to the shape of the cavity without creative work, for example, the shape of the first radiation slot 106 may also be various shapes such as a circle, a diamond, etc., as long as the purpose of the invention is achieved, and the radiation slot may be any one of a rectangle, an ellipse, a T, a cross, and a dumbbell; the coupling gap can be any one of a rectangle, an ellipse, a cross and a dumbbell; the feed waveguide can be a mold cavity with closed periphery and can also be periodically slotted; the resonant cavity can be a cavity with closed periphery or can be periodically slotted.

The working process of the dual-polarized antenna is as follows: when horizontally polarized transmitted electromagnetic energy is fed into the end cavity, electromagnetic field perturbations are induced by the metal step and the transmitted energy is coupled into the first resonant cavity 105. The coupled energy excites electromagnetic waves distributed in the horizontal direction within the first resonant cavity 105, causing the radiating slots of the four "cross-shaped" radiating slots to excite horizontal electric fields, thereby forming horizontally polarized waves.

Referring to fig. 2 and 3, it can be seen that, after the Ka-band dual-polarized antenna unit based on resonant cavity radiation of the present invention is applied, the magnetic field distribution and the electric field distribution both achieve the design goal, the magnetic field distribution is uniform and compact, and the electric field distribution is within the range of the radiation gap, so as to obtain a good effect.

Referring to the antenna horizontal polarization directional diagram of fig. 4A with the center frequency of 35GHz and the antenna vertical polarization directional diagram of fig. 4B with the center frequency of 35GHz, in the 2 x 2 antenna array unit structure applying the present invention, the center frequency of the antenna array unit is set to 35GHz, electromagnetic energy transmitted by vertical polarization passes through the "in-line" coupling slot and is coupled to the first resonant cavity 105 through the circular cavity at the end of the horizontally polarized feed waveguide, the energy coupled to the first resonant cavity 105 can excite the electromagnetic wave of TM210 mode distributed along the horizontal direction in the resonant cavity, so that the longitudinal slits in the four "cross" radiation slots are radiated to excite the electric field in the vertical direction to form vertical polarized waves, it can be seen that the superposition of the main lobes of the E-plane directional diagram and the H-plane directional diagram of the dual-polarized antenna of the present invention is better, the gain of horizontal polarization is 14.4dBi, the gain of the vertical polarization is 14.2dBi, the cross polarization of the antenna unit is better than 25 dB in the beam width of 3dB, and the antenna unit is in a good state.

Please refer to fig. 5: after simulation optimization, the return loss diagrams of the ports of the dual-polarized antenna units show that the return loss of the antenna units after horizontal polarization and vertical polarization are in a controllable range, the matching conditions of the two input ends are consistent, the return loss of the feed ports of the antenna vertical polarization and the antenna horizontal polarization in the range of 27 GHz-40 GHz is better than-15 dB, and the design purpose is achieved.

Referring to fig. 6, a schematic diagram of a second embodiment of the dual-polarized antenna unit structure of the present invention is shown, in which the second radiation slots 107 are designed as 4 cross-shaped slots, and the second resonant cavities 108 are designed as resonant cavities with recessed portions at four corners, and experimental data of the antenna unit can also achieve the purpose of the present invention, so as to achieve the design goals of horizontal polarization and vertical polarization.

In the present invention, the positions of the four radiation slots are reasonably selected, such that the wide sides of the radiation slots are approximately parallel to and symmetrically distributed with the magnetic field tangent of the TM210 mode electromagnetic wave, and the four slots can cut the in-phase current, so as to excite the radiation field, further referring to fig. 7, which is a cross-sectional view of the dual-polarized antenna unit structure shown in fig. 1, wherein the length sa of the first radiation slot 106 is about 1 free space wavelength at the central frequency, the length ca of the first resonant cavity 105 is about 0.8 free space wavelength at the central frequency, and the length of the coupling slot 102 is about 0.5 waveguide wavelength.

Claims

1. A Ka-band dual polarized antenna unit structure based on resonant cavity radiation, comprising: the dual-polarized antenna comprises a vertical polarization feed waveguide, a horizontal polarization feed waveguide, a coupling gap, a resonant cavity and a radiation gap, wherein the vertical feed waveguide and the horizontal feed waveguide enable electromagnetic waves to form constrained electromagnetic waves, the electromagnetic waves are coupled at the coupling gap and further coupled to the radiation gap through the coupling gap, and the resonant cavity, the vertical polarization feed waveguide and the horizontal polarization feed waveguide realize the dual-polarized antenna through orthogonal feed.

2. The structure of a Ka-band dual polarized antenna element as claimed in claim 1, wherein said resonant cavity is further an air cavity.

3. The structure of the Ka-band dual-polarized antenna unit of claim 1, wherein the radiation slot is any one of a rectangle, an ellipse, a T-shape, a cross-shape and a dumbbell-shape.

4. The structure of the Ka-band dual polarized antenna unit according to claim 1, wherein the coupling slot may be any one of a rectangle, an ellipse, a cross, and a dumbbell.

5. The structure of a Ka-band dual polarized antenna element as claimed in claim 1, wherein the feed waveguide is a mold cavity with a closed periphery, and may be a slot periodically.

6. The structure of a Ka-band dual polarized antenna unit according to claim 1, wherein the resonant cavity is a cavity with a closed periphery or a cavity with a periodic slot.