Opposite-fed waveguide array antenna with simple structure

Abstract

The utility model discloses a feed waveguide array antenna with a simple structure, which comprises a one-to-two power divider, a first feed line, a second feed line, a first one-to-n power divider, a second one-to-n power divider and n radiation slot groups, n is a natural number greater than 1, one output end of the one-to-two power divider is connected with one end of the first feed line, and the other output end of the one-to-two power divider is connected with the other end of the second feed line. The other output end of the one-to-two power divider is connected with one end of a second feeder, the other end of the first feeder is connected with the input end of a first one-to-n power divider, n output ends of the first one-to-n power divider are connected with one ends of n radiation slot groups respectively, the other end of the second feeder is connected with the input end of a second one-to-n power divider, and n is an integer greater than or equal to 2. And n output ends of the second one-to-n power divider are respectively connected with the other ends of the n radiation slot groups. The utility model has the advantages of simple structure, stable performance and low cost.

Description

Technical Field

[0001] This utility model relates to a waveguide array antenna, and more particularly to a simple-structured feed-in waveguide array antenna, belonging to the field of antenna technology. Background Technology

[0002] In the E-band (60-90 GHz) frequency range, especially in the 74-81 GHz range, the design of high-gain array antennas faces numerous challenges. First, due to the high frequency and short wavelength (approximately 3.75-4 mm), the antenna manufacturing precision requirements are extremely high; even minute dimensional errors can significantly impact performance. Second, achieving high gain typically necessitates multi-layer structures or complex feed networks, which not only increases design and manufacturing difficulty but may also lead to increased antenna size and weight, making it difficult to meet the compactness and lightweight requirements of automotive millimeter-wave radar.

[0003] The plastic metallization process is a low-cost manufacturing technique widely used in the fabrication of high-frequency waveguide antennas. This process involves injection molding a plastic substrate and then metallizing its surface, enabling the manufacture of high-precision and complex structures while significantly reducing production costs. Compared to traditional metal processing methods, plastic metallization is not only more cost-effective but also meets the high precision and low-loss requirements of the E-band.

[0004] Chinese Patent Publication No. CN118352801A discloses a slot array antenna, comprising, from top to bottom, a radiating aperture array layer, a radiating waveguide layer, and a feed network layer. The radiating aperture array layer and the radiating waveguide layer are combined to form a waveguide slot array. The feed network layer includes a base plate and multiple cascaded power dividers arranged on the base plate. Multiple periodically arranged metal pillars are also arranged on the base plate to form an electromagnetic bandgap structure. The multiple power dividers are configured to: divide the electromagnetic energy input to the first-stage equal power divider into two paths, which are then transmitted to the second-stage T-type unequal power divider and further divided into four paths; then input to the third-stage T-type unequal power divider and further divided into eight paths; finally, the electromagnetic energy is output in sixteen paths through the fourth-stage Y-type unequal power divider. The array antenna of this invention features high gain, low sidelobes, high aperture efficiency, and a compact structure.

[0005] This design employs a three-layer structure and a center-fed method to avoid the problem of antenna radiation pattern beam pointing angle deflection. However, the structure is complex and uses a complicated feeding network. Currently available millimeter-wave radar antennas have compact structures, and it is difficult to arrange complex feeding networks in the E-band.

[0006] Chinese Patent Publication No. CN113054444A discloses a novel W-band miniaturized high-gain waveguide antenna array, comprising: antenna elements, a feeding network, and a feeding port. The antenna elements are located at the top, the three-layer feeding network is located in the middle, and the feeding port is located at the bottom; the feeding network is interconnected with the antenna elements and the feeding port. This invention relates to a novel W-band miniaturized high-gain waveguide antenna array operating at 94 GHz, which has advantages such as miniaturization, high gain, and simple structure, and is expected to play an important role in the field of millimeter-wave waveguide antenna technology.

[0007] The design employs a multi-layer structure, and the complex centimeter network design makes it difficult to process and manufacture.

[0008] Chinese Patent Publication No. CN115189150B discloses a low-sidelobe waveguide slot array antenna and its design method. This invention reverses the radiating slot portion of the waveguide slot array antenna, dividing the slot elements into in-phase and out-of-phase elements. There is a 180° phase difference between the in-phase and out-of-phase elements. By optimizing the positions of the in-phase and out-of-phase elements, a two-dimensional low-sidelobe shaping of the waveguide slot array antenna is achieved simultaneously in a plane parallel to the electric field direction and a plane parallel to the magnetic field direction. This invention is characterized by its simple design and ease of implementation.

[0009] The invention uses a side-feed form, which has the problem of beam pointing angle deflection. Furthermore, the offset gap will cause the radiated energy to be asymmetrical in spatial distribution, with some energy concentrated in a specific direction, thus generating side lobes in non-main lobe directions (i.e., large angle directions).

[0010] Therefore, it can be seen that the existing technology has the following defects:

[0011] 1. It adopts a multi-layer structure, which is relatively complex and difficult to manufacture. Furthermore, small errors in the multi-layer structure in the E-band will be amplified.

[0012] 2. When using side-fed radar, the cumulative phase error caused by the asymmetry of the antenna structure often leads to a shift in the beam pointing angle. This shift reduces the detection accuracy and target positioning capability of the radar system, adversely affecting the performance of the vehicle-mounted millimeter-wave radar.

[0013] 3. By adopting the traditional offset slit form, the radiated energy is asymmetrically distributed in space, thus generating higher side lobes in the non-main lobe direction (i.e., the large angle direction). Utility Model Content

[0014] The technical problem to be solved by this utility model is to provide a simple feed waveguide array antenna with simple structure, stable performance and low cost.

[0015] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0016] A simple counter-fed waveguide array antenna includes a 1-to-2 power divider, a first feed line, a second feed line, a first 1-to-n power divider, a second 1-to-n power divider, and n groups of radiating slots, where n is a natural number greater than 1. One output terminal of the 1-to-2 power divider is connected to one end of the first feed line, and the other output terminal of the 1-to-2 power divider is connected to one end of the second feed line. The other end of the first feed line is connected to the input terminal of the first 1-to-n power divider. The n output terminals of the first 1-to-n power divider are each connected to one end of the n groups of radiating slots. The other end of the second feed line is connected to the input terminal of the second 1-to-n power divider, and the n output terminals of the second 1-to-n power divider are each connected to the other end of the n groups of radiating slots.

[0017] Furthermore, it includes a first antenna layer and a second antenna layer. The first antenna layer is located above the second antenna layer. The 1-to-2 power divider, the first feed line, the second feed line, the first 1-to-n power divider, and the second 1-to-n power divider are divided into two parts and respectively located below the first antenna layer and above the second antenna layer.

[0018] Furthermore, each of the aforementioned radiating slot groups includes a waveguide and a plurality of radiating slots, the plurality of radiating slots being linearly distributed along the length of the radiating slots on the upper side of the waveguide.

[0019] Furthermore, it also includes n+1 choke slots, which are arranged parallel to each other and are distributed at equal intervals along the width direction of the radiation slots on the first antenna layer. Each radiation slot group is located in the middle of the gap between two adjacent choke slots, and the n radiation slot groups are respectively arranged in the gaps of the n+1 choke slots.

[0020] Furthermore, a metal block is provided on one side of each of the radiation slits, and in two adjacent radiation slits, the metal block of one radiation slit is provided on the left side of the radiation slit, and the metal block of the other radiation slit is provided on the right side of the radiation slit.

[0021] Furthermore, among the plurality of radiating slits, the distance between the metal blocks and the radiating slits gradually increases from the median of the radiating slits toward both sides.

[0022] Furthermore, the first feed line and the second feed line are E-plane feed lines. The other end of the first feed line is connected to the input terminal of the first 1-to-n power divider through the first E-plane to H-plane waveguide, and the other end of the second feed line is connected to the input terminal of the second 1-to-n power divider through the second E-plane to H-plane waveguide.

[0023] Compared with the prior art, this utility model has the following advantages and effects:

[0024] 1. This utility model adopts a two-layer structure, which greatly simplifies the complexity of the antenna; the reduction in the number of layers not only reduces the processing difficulty and assembly cost, but also improves the product yield and consistency; in the E-band frequency band, due to the short wavelength, the small errors in the multi-layer structure will be amplified, while this utility model effectively avoids this problem by reducing the number of layers.

[0025] 2. This utility model adopts a counter-feed structure, which ensures the phase consistency between radiating elements through a symmetrical feeding network, thereby effectively suppressing the offset of the beam pointing angle and ensuring that the main beam direction of the antenna is always aligned with the expected target.

[0026] 3. This utility model can change the electric field distribution around the radiation port by loading a metal block under the radiation port, thereby enabling radiation. The design and manufacturing are relatively simple, and it avoids the asymmetric spatial distribution of radiation energy caused by the offset gap, thus generating a higher number of side lobes in the non-main lobe direction (i.e., the large angle direction). Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a simple feed-in waveguide array antenna according to this utility model.

[0028] Figure 2 This is a structural diagram of a simple feed-fed waveguide array antenna according to this utility model.

[0029] Figure 3 This is a schematic diagram of one side of the first antenna layer of this utility model.

[0030] Figure 4 This is a schematic diagram of the other side of the first antenna layer of this utility model.

[0031] Figure 5 This invention relates to the radiation patterns of the center frequency point E-plane and H-plane of a simple feed-in waveguide array antenna.

[0032] Figure 6 This is a schematic diagram of the operating bandwidth performance of a simple feed-in waveguide array antenna according to this utility model. Detailed Implementation

[0033] To elaborate on the technical solutions adopted by this utility model to achieve the intended technical objectives, the technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Furthermore, the technical means or technical features in the embodiments of this utility model can be replaced without creative effort. The utility model will be described in detail below with reference to the accompanying drawings and embodiments.

[0034] like Figure 1 As shown, this utility model discloses a simple counter-fed waveguide array antenna, comprising a 1-to-2 power divider 1, a first feed line 2, a second feed line 3, a first 1-to-4 power divider 4, a second 1-to-4 power divider 5, and four radiating slot groups. One output terminal of the 1-to-2 power divider 1 is connected to one end of the first feed line 2, and the other output terminal of the 1-to-2 power divider 1 is connected to one end of the second feed line 3. The other end of the first feed line 2 is connected to the input terminal of the first 1-to-4 power divider 4, and the four output terminals of the first 1-to-4 power divider 4 are respectively connected to one end of each of the four radiating slot groups. The other end of the second feed line 3 is connected to the input terminal of the second 1-to-4 power divider 5, and the four output terminals of the second 1-to-4 power divider 5 are respectively connected to the other ends of each of the four radiating slot groups. Using a counter-fed structure for feeding ensures the symmetry of the antenna's radiating structure, thereby preventing deflection of the antenna's radiation pattern.

[0035] The first feed line 2 and the second feed line 3 are E-plane feed lines. The other end of the first feed line 2 is connected to the input terminal of the first 1-to-4 power divider 4 through the first E-plane to H-plane waveguide 6. The other end of the second feed line 3 is connected to the input terminal of the second 1-to-4 power divider 5 through the second E-plane to H-plane waveguide 7.

[0036] like Figure 2 As shown, a simple feed waveguide array antenna of this utility model includes a first antenna layer 8 and a second antenna layer 9. The first antenna layer 8 is disposed on the upper side of the second antenna layer 9. The 1-to-2 power divider 1, the first feed line 2, the second feed line 3, the first 1-to-4 power divider 4, and the second 1-to-4 power divider 5 are divided into two parts and disposed on the lower side of the first antenna layer 8 and the upper side of the second antenna layer 9, respectively. Figure 1 and Figure 2 It is a drawing of a complementary structure. Figure 2 This is a schematic diagram of the actual product, and Figure 1 This is a schematic diagram of the antenna design, namely Figure 1 The feed line, power divider, and other structures are actually slotted into a plastic-metal plate. Because the thickness of the stepped impedance matching part of some structures, such as the first E-plane to H-plane waveguide 6 and the second E-plane to H-plane waveguide 7, is relatively small, the smaller parts are actually presented directly as openings on the first antenna layer 8.

[0037] like Figure 1 As shown, each radiating slot group includes a waveguide 10 and four radiating slots 11, which are arranged in a straight line along the length of the waveguide 10. This invention comprises four radiating slot groups, each with four radiating slots 11, forming a 4*4 waveguide array antenna.

[0038] The present invention provides a simple feed-through waveguide array antenna, which also includes five choke slots 12. The five choke slots 12 are arranged in parallel to each other and are evenly distributed on the first antenna layer 8 along the width direction of the radiation slots 11. Each radiation slot group is located in the middle of the gap between two adjacent choke slots 12, and four radiation slot groups are respectively arranged in the gap between the five choke slots 12.

[0039] like Figure 1 , Figure 3 and Figure 4 As shown, a metal block 13 is provided on one side of each radial slit 11. In two adjacent radial slits 11, the metal block 13 of one radial slit 11 is located on the left side of the radial slit 11, and the metal block 13 of the other radial slit 11 is located on the right side of the radial slit 11. In this way, in each group of four radial slits, the metal blocks 13 are staggered on both sides of the four radial slits 11. Moreover, in the four groups of four radial slits, the metal blocks 13 of the two left radial slit groups are symmetrically distributed with respect to the interval lines of the two left radial slit groups, the metal blocks of the two right radial slit groups are symmetrically distributed with respect to the interval lines of the two right radial slit groups, and the metal blocks 13 of the two middle radial slit groups are distributed in the same position.

[0040] Of the four radiating slots 11, the distance between the metal blocks 13 and the slots gradually increases from the median of the radiating slot 11 towards the two outermost slots. That is, the metal blocks 13 in the two middle radiating slots 11 are closer to these two slots, while the metal blocks 13 in the two outermost radiating slots 11 are farther away. The array antenna elements are typically placed at half-wavelength intervals, resulting in a 180° phase difference between adjacent elements. This 180° phase difference is compensated by alternately placing the metal blocks, thereby achieving in-phase radiation and forming a focused beam, such as... Figure 5 The diagram shows the radiation patterns of the center frequency point E-plane and H-plane of the waveguide array antenna of this invention.

[0041] like Figure 6 The diagram shown is a schematic of the operating bandwidth performance of a simple counter-fed waveguide array antenna according to this utility model. It has good performance within the 75-80GHz bandwidth and has a wide operating bandwidth.

[0042] This invention employs a two-layer structure, greatly simplifying the complexity of the antenna. Reducing the number of layers not only lowers processing difficulty and assembly costs but also improves product yield and consistency. In the E-band, due to the shorter wavelength, minute errors in a multi-layer structure are amplified; this invention effectively avoids this problem by reducing the number of layers. The invention uses a counter-feed structure, ensuring phase consistency between radiating elements through a symmetrical feed network, thereby effectively suppressing beam pointing angle shifts and ensuring the antenna's main beam direction is always aligned with the intended target. By loading a metal block under the radiating port, this invention can change the electric field distribution around the radiating port, thus enabling radiation. This design is relatively simple to manufacture and avoids the asymmetrical spatial distribution of radiated energy caused by offset gaps, thereby generating higher sidelobes in non-main lobe directions (i.e., large-angle directions).

[0043] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model's technical solution. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present utility model's technical solution, based on the technical essence of the present utility model and within the spirit and principles of the present utility model, shall still fall within the protection scope of the present utility model's technical solution.

Claims

1. A simple-structured counter-fed waveguide array antenna, characterized in that: It includes a 1-to-2 power divider, a first feeder, a second feeder, a first 1-to-n power divider, a second 1-to-n power divider, and n groups of radiating slots, where n is a natural number greater than 1. One output terminal of the 1-to-2 power divider is connected to one end of the first feeder, and the other output terminal of the 1-to-2 power divider is connected to one end of the second feeder. The other end of the first feeder is connected to the input terminal of the first 1-to-n power divider. The n output terminals of the first 1-to-n power divider are each connected to one end of the n groups of radiating slots. The other end of the second feeder is connected to the input terminal of the second 1-to-n power divider, and the n output terminals of the second 1-to-n power divider are each connected to the other end of the n groups of radiating slots.

2. The simple-structured counter-fed waveguide array antenna according to claim 1, characterized in that: It includes a first antenna layer and a second antenna layer. The first antenna layer is located above the second antenna layer. The 1-to-2 power divider, the first feed line, the second feed line, the first 1-to-n power divider, and the second 1-to-n power divider are divided into two parts and located below the first antenna layer and above the second antenna layer, respectively.

3. The simple-structured counter-fed waveguide array antenna according to claim 2, characterized in that: Each of the aforementioned radiating slot groups includes a waveguide and a number of radiating slots, which are distributed in a straight line along the length of the waveguide.

4. A simple-structured counter-fed waveguide array antenna according to claim 3, characterized in that: It also includes n+1 choke slots, which are arranged parallel to each other and are distributed at equal intervals along the width direction of the radiation slots on the first antenna layer. Each radiation slot group is located in the middle of the gap between two adjacent choke slots, and the n radiation slot groups are respectively arranged in the gaps of the n+1 choke slots.

5. A simple-structured counter-fed waveguide array antenna according to claim 4, characterized in that: A metal block is provided on one side of each of the aforementioned radial slits. In two adjacent radial slits, the metal block of one radial slit is located on the left side of the radial slit, and the metal block of the other radial slit is located on the right side of the radial slit.

6. A simple-structured counter-fed waveguide array antenna according to claim 5, characterized in that: Among the aforementioned radiating slits, the distance between the metal blocks and the radiating slits gradually increases from the median of the radiating slit towards both sides.

7. A simple-structured counter-fed waveguide array antenna according to claim 1, characterized in that: The first feed line and the second feed line are E-plane feed lines. The other end of the first feed line is connected to the input terminal of the first 1-to-n power divider through the first E-plane to H-plane waveguide. The other end of the second feed line is connected to the input terminal of the second 1-to-n power divider through the second E-plane to H-plane waveguide.

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