CN221805852U - A gap waveguide structure, dual-frequency dual-polarization waveguide slot array antenna and radar - Google Patents

Abstract

The utility model discloses a gap waveguide structure, a dual-frequency dual-polarized waveguide gap array antenna and a radar, wherein the waveguide structure comprises a feed layer, a coupling layer and a radiation layer which are arranged in a stacked mode, the feed layer comprises a first feed network, a second feed network and a third feed network, a plurality of coupling cavities and gap waveguide metal columns are arranged in the second feed network, and vertical polarization coupling holes for distributing power of electromagnetic waves with horizontal polarization are formed in the coupling cavities. The utility model provides a gap waveguide structure, a dual-frequency dual-polarized waveguide gap array antenna and a radar, wherein the multi-layer gap waveguide feed structure reduces the feed network loss, improves the radiation efficiency of the antenna, and meets the high gain requirement of satellite communication.

Description

Gap waveguide structure, dual-frequency dual-polarized waveguide slot array antenna and radar

Technical Field

The present utility model relates to a waveguide structure, a waveguide slot array antenna and a radar, and more particularly, to a gap waveguide structure, a dual-frequency dual-polarized waveguide slot array antenna and a radar.

Background

At present, satellite communication is actively developed, and satellite application scenes such as high orbit, low orbit, navigation and the like are more and more abundant. The dual-frequency dual-polarization technology is an important direction of satellite communication antenna development, and can resist multipath fading and realize polarization diversity, thereby improving the quality and communication capability of received signals. The waveguide slot antenna array has been widely used in radar and communication due to the advantages of compact structure, high radiation efficiency, large power capacity, etc. The conventional transmission lines such as microstrip lines and strip lines have large loss, which brings trouble to the design of high-performance antennas, and the requirements of people cannot be met, so that improvement is needed.

Disclosure of utility model

The utility model aims to provide a gap waveguide structure, a dual-frequency dual-polarized waveguide gap array antenna and a radar, which utilize a multi-layer gap waveguide feed structure to reduce feed network loss, improve the radiation efficiency of the antenna, meet the high-gain requirement of satellite communication and solve the defects existing in the prior art.

The utility model provides the following scheme:

The gap waveguide structure comprises a feeding layer, a coupling layer and a radiation layer which are arranged in a stacked mode, wherein the feeding layer comprises a first layer of feeding network and a third layer of feeding network, a second layer of feeding network is arranged between the first layer of feeding network and the third layer of feeding network, a plurality of coupling cavities and gap waveguide metal columns are arranged in the second layer of feeding network, and vertical polarization coupling holes for distributing power to horizontally polarized electromagnetic waves are formed in the coupling cavities. It will be appreciated that a stacked arrangement is generally referred to as a composite layer structure, and that the connection between the composite layer structures may be achieved by means of prior art connections.

Horizontal polarization refers to the fact that when an antenna transmits or receives electromagnetic waves, the electric field component is parallel to the ground. For example, conventional outdoor antennas in broadcast television are horizontally polarized. Vertical polarization means that the electric field component is perpendicular to the ground when the antenna transmits or receives electromagnetic waves. For example, in wireless communications, ceramic patch antennas within wireless communications devices typically employ vertical polarization. By using array antenna systems of different polarization modes, different application requirements can be satisfied. For example, in satellite communications, in order to avoid the influence of the atmosphere on the radio signal caused by large interference, cross polarization technology (having both vertical polarization and horizontal polarization) is often used to achieve better transmission effect.

Further, the feeding layer, the coupling layer and the radiation layer are laminated in order from bottom to top, and in the feeding layer: the first layer feed network is a 1-division 64-power-division network formed by H-plane waveguide T-shaped junction power splitters, and comprises a first input port which is electromagnetically coupled with a vertical polarization coupling hole of the second layer feed network.

Furthermore, the third layer feed network is a 1-division 32-division network formed by H-plane waveguide T-shaped junction power dividers, and comprises a second input port through which electromagnetic waves enter the feed layer.

Furthermore, a plurality of rectangular grooves are uniformly formed in the coupling layer.

Further, the coupling layer is a rectangular coupling layer, and 64 rectangular grooves are formed in the rectangular coupling layer.

Furthermore, cross slit grooves are uniformly formed in the radiation layer.

Further, the cross-shaped slit groove is provided with a chamfer.

Further, the vertical length of the cross-shaped slit groove is greater than the horizontal length.

The waveguide slot array antenna comprises the gap waveguide structures, and the gap waveguide structures are fixedly connected through screws.

A radar in which the waveguide slot array antenna is provided.

The utility model provides a gap waveguide structure, a dual-frequency dual-polarized waveguide gap array antenna and a radar, wherein the multi-layer gap waveguide feed structure reduces the feed network loss, improves the radiation efficiency of the antenna, and meets the high gain requirement of satellite communication.

1) The gap waveguide technology can ensure normal propagation of electromagnetic waves, does not need any electric contact between a high-frequency microwave device and metal, has the characteristics of easiness in manufacturing, flexible and various gap distribution, low loss and the like, and is more beneficial to design of a high-gain array antenna.

2) The three-layer feed network is in-phase with the excitation unit radiation structure to generate a desired pattern.

3) And a rectangular gap structure is adopted above the feed layer, and the length and the width are adjusted to realize the impedance matching of orthogonal polarization.

4) The radiation structure adopts a cross waveguide slot, the design of the two polarization directions is not interfered with each other, the dual-frequency dual-polarization work can be realized by designing different lengths, and the design flexibility is high.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present utility model, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

Fig. 1 is a combined elevation view of a dual-frequency dual-polarized waveguide slot array antenna.

Fig. 2 is a combined perspective view of a dual-frequency dual-polarized waveguide slot array antenna.

Fig. 3 is a dispersed elevation view of a dual-frequency dual-polarized waveguide slot array antenna.

Fig. 4 is a dispersed perspective view of a dual-frequency dual-polarized waveguide slot array antenna.

Fig. 4a is an enlarged view of a portion of fig. 4.

Fig. 5 is an elevation view of a feed layer first layer feed network.

Fig. 6 is a perspective view of fig. 5.

Fig. 7 is a rear view of a feed layer first layer feed network.

Fig. 8 is a perspective view of fig. 7.

Fig. 9 is an elevation view of a feed layer second layer feed network.

Fig. 10 is a perspective view of a feed layer second layer feed network.

Fig. 11 is a rear view of a feed layer second layer feed network.

Fig. 12 is an elevation view of a feed layer third layer feed network.

Fig. 13 is a perspective view of a third layer feed network of the feed layer.

Fig. 14 is a rear view of a feed layer third layer feed network.

Fig. 15 is a front view of a rectangular coupling layer.

Fig. 16 is a perspective view of a rectangular coupling layer.

Fig. 17 is a front view of a radiation layer.

Fig. 18 is a perspective view of a radiation layer.

Fig. 19 is a return loss diagram of the present utility model.

Detailed Description

The following description of the embodiments of the present utility model will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the utility model are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

Reference numerals illustrate:

The feed network 11 of the first layer, the first feed port 12, the second feed port 13, the gap waveguide metal pillar 14, the power division network 15, the first input port 16, the second feed network 21, the vertical polarization coupling hole 22, the coupling cavity 23, the third feed network 31, the horizontal polarization coupling hole 32, the cross polarization coupling hole 33, the second input port 34, the coupling layer 41, the rectangular slot 42, the radiation layer 51,2 ×2 subunit 52, the cross slot 53, the screw hole 54.

As shown in fig. 1 to 4, the gap waveguide structure in this embodiment is a composite layer structure designed based on the gap skin technology, and the coupling layer includes a cross coupling hole and a rectangular slot, and the radiation layer is composed of a quarter back cavity and a cross slot 53, and the whole structure is fed from the bottom by using a standard waveguide port, and the feed layer, the coupling layer and the radiation layer are laminated in the order from bottom to top.

The utility model provides a gap waveguide structure, a dual-frequency dual-polarized waveguide gap array antenna and a corresponding radar, wherein the waveguide gap array antenna comprises the gap waveguide structure, the gap waveguide structures are fixedly connected through screws, and the waveguide gap array antenna is arranged in the radar. The slot array antenna is a dual-frequency dual-polarized waveguide slot array antenna, the array antenna comprises three layers of radiation structures formed by a gap waveguide feed network and cross slots, the array antenna based on the gap waveguide technology is an important application direction of the gap waveguide technology, the three layers of feed networks in the embodiment all adopt the gap waveguide technology, and the integration of the array antenna feed network and the antenna can be realized conveniently by adopting the gap waveguide technology.

In a possible embodiment, the dual-frequency dual-polarized waveguide slot array antenna based on the gap waveguide technology provided by the embodiment of the utility model realizes dual-polarized operation by designing a three-layer gap waveguide feed network and cross slot grooves, and realizes dual-frequency operation by designing different slot lengths. The design method is flexible and simple, and the mechanical assembly is simple.

As shown in fig. 5 to 8 and fig. 9 to 14, the feeding layer includes a first layer feeding network 11 and a third layer feeding network 31, a second layer feeding network 21 is disposed between the first layer feeding network and the third layer feeding network, a plurality of coupling cavities and gap waveguide metal columns are disposed in the second layer feeding network 21, and vertical polarization coupling holes for distributing power to electromagnetic waves with horizontal polarization are formed in the coupling cavities for realizing in-phase unit excitation.

Specifically, in the feed layer, the first layer feed network 11 is a 1-to-64 power division network formed by an H-plane waveguide T-type junction power divider, the power division network is used for distributing input signals to a plurality of output ports according to a specific proportion, a terminal of the first layer feed network is a short circuit waveguide, the first layer feed network includes a first input port, and the first input port is electromagnetically coupled with a vertical polarization coupling hole of the second layer feed network.

Feeding refers to the input of energy into a device or system, and coupling refers to the existence of an interactive, interrelated relationship between two or more elements. Illustratively, in this embodiment, the first layer feed network and the second layer feed network are coupled by an air medium that vertically polarizes the coupling holes.

Radiation refers to the propagation of energy from an object to the surrounding environment in a wireless manner. In feed-coupled radiation, when an electromagnetic signal passes through a line, a magnetic or electric field may be generated in the vicinity of the line, and these fields radiate wirelessly to the surrounding environment.

Specifically, the third layer of feeding network 31 is a 1-32 power division network composed of H-plane waveguide T-junction power dividers, the third layer of feeding network includes a gap waveguide metal column, a power division network and an output port, a semi-enclosed cavity is formed, and a cross coupling hole site is arranged above the semi-enclosed cavity for enabling the radiation layer 51 to obtain energy from the feeding layer.

The gap waveguide metal columns 14 are distributed around the power division network as metal walls, so that leakage of electromagnetic waves is suppressed, and loss of a feed network is reduced. However, when the rectangular waveguide H-plane T-junction power divider is adopted for horizontal polarization, the magnetic current of the output port is inverted, which causes wave beam distortion and gain loss of the antenna, in order to solve the technical problem, the utility model adopts a phase compensation measure to improve the directional diagram of the horizontal polarization array, and adds a layer of rectangular waveguide structure (namely the second layer of feed network 21), the waveguide coupling gap H-plane T-junction power divider is adopted to realize the in-phase characteristic between the output ports, the horizontal polarization feed waveguide positioned at the third layer feeds through the coupling cavity 23 of the lower layer, the fed electromagnetic wave can be transmitted to the two ends of the waveguide, the longitudinal gaps in the cross polarization coupling holes 33 close to the short circuit wall can intercept the magnetic current component of horizontal polarization, and the magnetic current fed by the two adjacent 2×2 subunits 52 are in-phase with equal amplitude at the moment, so that the horizontal polarization array can obtain energy superposition and wave beam, and realize the high gain of the antenna. The pattern of the 2 x 2 subunit 52 multiplied by the array factor is the pattern characteristic of the array antenna.

Description of principle: the pattern characteristics of an array antenna depend primarily on the design and layout of the array antenna. The array antenna generates special radiation characteristics by utilizing the interference principle and the superposition principle of electromagnetic waves. The individual radiators that make up the array antenna are referred to as elements. By varying the phase of the excitation current of each element antenna in the array, its radiation pattern can be scanned spatially.

The pattern characteristics of an array antenna generally include parameters such as beam width, side lobe level, front-to-back ratio, and scan range. The beam width refers to the main lobe width, namely the width of the radiation intensity of the antenna along with the change of the angle; the side lobe level refers to the ratio of the maximum value of the side lobe to the maximum value of the main lobe; the front-to-back ratio refers to the ratio of the maximum radiation direction to the radiation intensity in the opposite direction; the scan range refers to the angular range that the antenna beam can cover.

The pattern characteristics of the array antenna can be improved by optimizing the layout and the number of units of the array, selecting proper materials and sizes, adjusting excitation amplitude and phase and the like, so that the antenna can obtain narrower main lobe width, lower side lobe level, higher front-back ratio and wider scanning range, thereby improving the radiation efficiency and the directivity of the antenna, and better pattern characteristics can be obtained by optimizing the design, adjusting the layout and parameters and the like, thereby improving the radiation efficiency and the directivity of the antenna.

The second layer feeding network and the third layer feeding network are respectively provided with a vertical polarization coupling hole, and the third layer feeding network is provided with a corresponding horizontal polarization feeding coupling hole.

A second input port 34 is included in the third layer feed network 31, through which second input port 34 electromagnetic waves enter the feed layer. After the electromagnetic wave enters the feed layer, the electromagnetic wave enters the coupling cavity 23 downwards through the horizontal polarization coupling hole 32, is transmitted to two ends of the waveguide with strong coupling, and enters the radiation layer 51 upwards through the cross polarization coupling hole 33, so as to generate horizontal polarization radiation.

The third layer of feed network 31 is a 1-division 32-power-division network composed of H-plane waveguide T-junction power splitters, the terminal is a short-circuit waveguide, and a coupling feed slot is placed on a broadside mid-line about λg/4 from the waveguide short-circuit wall. Electromagnetic waves enter the feed layer through the second input port 34, enter the coupling cavity 23 downwards through the horizontal polarization coupling hole 32, are transmitted to the two ends of the waveguide with strong coupling, enter the radiation layer 51 upwards through the cross polarization coupling hole 33, and generate horizontal polarization radiation.

As shown in fig. 15 and 16, a plurality of rectangular grooves 42 are uniformly formed in the coupling layer 41, and the rectangular grooves 42 function to allow two polarized electromagnetic waves to enter the radiation layer 51 therethrough, and to adjust the length and width to achieve good impedance matching. Illustratively, in this embodiment, 64 rectangular grooves 42 are formed on the rectangular coupling layer, and two polarized electromagnetic waves enter the radiation layer 51 through the rectangular grooves 42, so that good impedance matching is achieved by adjusting the length and width of the rectangular grooves 42.

As shown in fig. 17 and 18, the radiation layer 51 is uniformly provided with cross slit grooves 53, and the radiation structure adopts the cross slit grooves 53 to realize two polarizations, wherein the designs of the two polarization directions are not interfered with each other, and slits with different lengths are designed to enable each polarization to work in different frequency bands. Wherein, the cross-shaped gap and the coupling hole are provided with chamfers so as to reduce the production process difficulty of the high-gain dual-frequency dual-polarized array antenna.

Illustratively, according to one embodiment of the present utility model, the cross-shaped slot 53 has a vertical length that is greater than a horizontal length such that the horizontally polarized operating band is less than the vertically polarized operating band.

The gap waveguide structure and the dual-frequency dual-polarized waveguide gap array antenna designed based on the gap waveguide structure are of a flat waveguide structure, five layers of metal plates are processed by adopting a milling technology, a certain number of screw holes 54 are formed in the periphery of the metal plates, an assembled product is fixed through screws, and the waveguide array antenna feeds through waveguide ports at the bottom, such as a first feed port 12 and a second feed port 13.

As shown in the return loss diagram of fig. 19, the vertical length of the cross slot is designed to be greater than the horizontal length, the horizontal polarization working frequency band is smaller than the vertical polarization working frequency band, and the array antenna realizes dual frequency band/dual polarization. The working frequency bands of the array antenna cover 12.25-12.75GHz and 14-14.5GHz respectively, and are the receiving and transmitting frequency bands of Ku-band satellite communication. The array antenna in the embodiment is applied to a satellite communication system, particularly Ku frequency bands (12.5 GHz and 14.25 GHz), can realize the integration of a receiving frequency band and a transmitting frequency band on a limited common caliber, and can maintain the radiation performance with high efficiency and high gain.

In summary, the utility model provides a dual-frequency dual-polarized waveguide slot array antenna based on a gap waveguide technology, and the multi-layer gap waveguide feed structure reduces the feed network loss, improves the radiation efficiency of the antenna, and meets the high gain requirement of satellite communication. In addition, the slot grooves with different lengths are designed to realize dual-frequency dual-polarized work, so that the communication capacity is increased, and the system cost is reduced.

It will be understood by those skilled in the art that all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this utility model belongs unless defined otherwise. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

It should be noted that certain terms are used throughout the description and claims to refer to particular elements. It will be appreciated by those of ordinary skill in the art that different manufacturers, manufacturers may refer to a component by different names. The description and claims do not differ by the way in which they distinguish between components, but rather differ by the way in which they function.

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

Furthermore, those skilled in the art will appreciate that while some embodiments described herein include some features but not others included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the utility model and form different embodiments. For example: any of the embodiments claimed in the claims may be used in any combination of the embodiments of the utility model.

In the description of the present specification, the descriptions of the terms "one embodiment," "example," "specific example," and the like, mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present utility model. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present utility model, and not for limiting the same; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the utility model.

Claims (10)

1. A gap waveguide structure comprising a feeding layer, a coupling layer and a radiation layer which are arranged in a stacked manner, wherein the feeding layer comprises a first layer feeding network and a third layer feeding network, characterized in that a second layer feeding network is arranged between the first layer feeding network and the third layer feeding network, the second-layer feeding network is internally provided with a plurality of coupling cavities and gap waveguide metal columns, and vertical polarization coupling holes for distributing power to horizontally polarized electromagnetic waves are formed in the coupling cavities.

2. The gap waveguide structure according to claim 1, wherein the feed layer, the coupling layer, and the radiation layer are stacked in the order from bottom to top, in which: the first layer feed network is a 1-division 64-power-division network formed by H-plane waveguide T-shaped junction power splitters, and comprises a first input port which is electromagnetically coupled with a vertical polarization coupling hole of the second layer feed network.

3. The gap waveguide structure according to claim 2, wherein the third layer feeding network is a 1-to-32 power division network composed of H-plane waveguide T-junction power splitters, and the third layer feeding network includes a second input port through which electromagnetic waves enter the feeding layer.

4. The gap waveguide structure of claim 1, wherein the coupling layer is uniformly provided with a plurality of rectangular grooves.

5. The gap waveguide structure of claim 4, wherein the coupling layer is a rectangular coupling layer, and the rectangular coupling layer has 64 rectangular grooves formed thereon.

6. The gap waveguide structure of claim 1, wherein cross-shaped gap grooves are uniformly formed in the radiation layer.

7. The gap waveguide structure of claim 6, wherein the cross-shaped slot is chamfered.

8. The gap waveguide structure of claim 6, wherein the cross-shaped slot has a vertical length that is greater than a horizontal length.

9. A waveguide slot array antenna, characterized in that the waveguide slot array antenna comprises the gap waveguide structure of any one of claims 1 to 8, and the gap waveguide structures are fixedly connected through screws.

10. A radar, characterized in that the waveguide slot array antenna as claimed in claim 9 is provided in the radar.