W-band active phased array

Abstract

The invention discloses a W-band active phased array, which relates to the application fields of airborne imaging radars, automobile anti-collision radars and the like, and comprises a waveguide array and a plurality of PCB (Printed Circuit Board) dielectric plates, the upper end face of the waveguide array is of a planar structure and serves as the radiation end of the phased array, and the lower end face of the waveguide array is of a non-planar three-dimensional layout and serves as the feed end of the phase PCB phased array. And the plurality of PCB dielectric plates are used as feed adapter plates and are arranged on the lower end surface of the waveguide array. By adopting a special-shaped array mode, the heat dissipation capability of the antenna is improved, and the performance of the antenna can be ensured while the power capacity of the antenna is increased in a limited space.

Description

Technical Field

[0001] The present invention belongs to the technical fields of airborne imaging radar, automobile anti-collision radar, etc., and particularly relates to a W-band active phased array. Background Art

[0002] With the development of wireless communication technology, the application of millimeter-wave antennas has attracted widespread attention, especially in the W-band (75-110 GHz). W-band antennas are the preferred choice for millimeter-wave antennas due to their short wavelength, high gain, wide bandwidth, narrow beam, and low sidelobe characteristics. Thanks to their high-resolution imaging and high-precision detection capabilities, they meet the application requirements of antenna miniaturization and high integration.

[0003] Active phased arrays (APEs), a special type of antenna consisting of multiple antenna elements, are a key antenna technology, particularly important in W-band applications. These arrays are often implemented as planar arrays, where all antenna elements are located on the same plane. This allows for two-dimensional scanning (in both azimuth and elevation), thereby controlling the beam's direction.

[0004] However, W-band antennas are smaller due to their shorter wavelengths. Smaller antennas must withstand higher power density at the same power level, leading to overheating of the antenna unit. Improper heat dissipation design can not only degrade antenna performance but also damage the antenna structure. Therefore, the power handling capacity of W-band antennas may be lower than that of antennas in other frequency bands, affecting their overall performance.

[0005] Therefore, how to improve the power capacity and heat dissipation efficiency of W-band active phased arrays within a limited space is an important technical challenge. Summary of the Invention

[0006] In view of this, the present invention provides a W-band active phased array, which adopts a special-shaped array method (i.e., a non-planar array method) to improve the antenna's heat dissipation capability, and can increase the antenna's power capacity within a limited space while ensuring antenna performance.

[0007] The present invention is achieved through the following technical solutions:

[0008] A W-band active phased array comprising: a waveguide array and a plurality of PCB dielectric boards;

[0009] The upper end surface of the waveguide array is a planar structure, serving as the radiating end of the phased array, and the lower end surface is a non-planar three-dimensional layout, serving as the feeding end of the phased PCB array;

[0010] Several PCB dielectric boards are used as feeding adapter boards and are arranged on the lower end surface of the waveguide array.

[0011] Furthermore, the waveguide array is composed of a plurality of waveguides arranged and combined at different heights; the upper end opening of each waveguide is a radiation port, and the lower end opening is a feed port; the radiation ports of the plurality of waveguides are flush, forming a radiation end of a phased array; the feed ports of the plurality of waveguides are arranged in a non-planar three-dimensional layout, forming a feed end of a phased array;

[0012] The PCB dielectric plates are arranged at the feed ports of the waveguide in a one-to-one correspondence.

[0013] Furthermore, it also includes: a plurality of microstrip lines;

[0014] The microstrip lines are arranged on the upper end surface of the PCB dielectric board in a one-to-one correspondence, and the microstrip lines extend to the radiation ports of the corresponding waveguides;

[0015] The microstrip line is connected to the strip line in the PCB dielectric plate through a coaxial metallized hole.

[0016] Furthermore, the waveguide array is composed of a plurality of waveguide line arrays;

[0017] The waveguide array is composed of one or more waveguides arranged horizontally; all waveguides in the same waveguide array have the same height, while the waveguides in adjacent waveguide arrays have different heights;

[0018] The PCB dielectric plates correspond one to one to the waveguide line arrays.

[0019] Furthermore, the lower end surface of the waveguide array is a stepped structure with a high middle and low ends;

[0020] The waveguide line array in the waveguide array is a 1×(2n+1) arrangement and combination, wherein n is a positive integer greater than 0.

[0021] Furthermore, the waveguide is a ridge waveguide.

[0022] Furthermore, the cavity of the waveguide is made of metal.

[0023] Furthermore, two adjacent PCB dielectric boards are stacked and arranged.

[0024] Furthermore, the PCB dielectric board is formed by bonding multiple layers of dielectrics; each of the PCB dielectric boards is formed by stacking and pressing two media in multiple layers.

[0025] Furthermore, the two dielectric materials of the PCB dielectric board are Rogers3003 and FR-28.

[0026] Beneficial effects:

[0027] (1) A W-band active phased array of the present invention has a non-planar three-dimensional layout at the lower end face of the phased array, and a plurality of PCB dielectric plates are used as feed adapter plates and are arranged on the lower end face of the waveguide array; the non-planar array is stacked to increase the heat dissipation area; at the same time, the original entire PCB dielectric plate is divided into several pieces, thereby increasing the heat dissipation area of the PCB dielectric plate and improving the heat dissipation effect of the active phased array.

[0028] (2) A W-band active phased array of the present invention comprises a waveguide array composed of a plurality of waveguides arranged and combined at different heights, wherein the radiation ports of the plurality of waveguides are flush, forming the radiation end of the phased array; the feed ports of the plurality of waveguides are arranged in a non-planar three-dimensional layout, forming the feed end of the phased array; PCB dielectric plates are arranged one-to-one at the feed ports of the waveguides, so that the PCB dielectric plates can be distributed at multiple different heights, making full use of space, enabling the integration of active devices of the active phased array, and further improving the power capacity of the active phased array.

[0029] (3) In a W-band active phased array of the present invention, the PCB dielectric board adopts stripline feeding, which can improve the anti-interference ability of the phased array and ensure the antenna performance; the microstrip line is connected to the stripline in the PCB dielectric board through a coaxial metallized hole, and the feeding method is changed from stripline feeding to microstrip radiation, which can reduce the occupied area of the active phased array and facilitate the integration of the antenna with other radio frequency components (such as power capacity amplifiers, etc.).

[0030] (4) In a W-band active phased array according to the present invention, the waveguide array is composed of a plurality of waveguide line arrays. All waveguides in the same waveguide line array have the same height. The PCB dielectric boards correspond one to one with the waveguide line array. The total number of PCB dielectric boards is reduced and the size is increased, which facilitates processing, making the structure simpler and easier to install. The waveguides in adjacent waveguide line arrays have different heights, thereby increasing the heat dissipation area and improving the heat dissipation effect.

[0031] (5) The W-band active phased array of the present invention has a ridge waveguide as the waveguide, which can further reduce the size of the active phased array. In addition, it can meet the needs of practical applications under limited space conditions, such as ±30° wide-angle scanning, low side lobes, and gain within the bandwidth, thereby reducing the cutoff frequency of the waveguide and ensuring antenna performance.

[0032] (6) In a W-band active phased array of the present invention, the waveguide cavity is made of metal. The metal material has good thermal conductivity, which can improve the heat dissipation effect and is conducive to increasing the power capacity.

[0033] (7) The W-band active phased array of the present invention is arranged in a stacked manner between two adjacent PCB dielectric plates, which can increase the surface area of the PCB dielectric plates, further improve the heat dissipation effect, and can be beneficial for further increasing the power capacity within a limited space. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the combined three-dimensional structure of the present invention;

[0035] Figure 2 Schematic diagram of the feeding end structure of the present invention;

[0036] Figure 3 It is the front view of the present invention;

[0037] Figure 4 is a side view of the present invention;

[0038] Figure 5 It is a schematic diagram of the exploded three-dimensional structure of the present invention;

[0039] Figure 6 A radiation port of a waveguide of the present invention;

[0040] Figure 7 Schematic diagram of the structure of a waveguide array of the present invention;

[0041] Figure 8 is a standing wave ratio and frequency curve of the active phased array in this embodiment 2;

[0042] Figure 9 is a normal gain versus frequency curve of the active phased array in Example 2;

[0043] Figure 10 The center frequency normal pattern and the elevation ±30° scanning pattern of the active phased array in Example 2;

[0044] Figure 11 The center frequency normal pattern and the azimuth ±30° scanning pattern of the active phased array in Example 2;

[0045] Among them, 1-waveguide array, 2-PCB dielectric board, 3-ridge waveguide port, 4-microstrip line, 5-waveguide, 6-waveguide line array. DETAILED DESCRIPTION

[0046] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0047] Example 1:

[0048] This embodiment provides a W-band active phased array, such as Figures 1 to 5 As shown, it includes: a waveguide array 1 and several PCB (printed circuit board) dielectric plates 2;

[0049] The waveguide array 1 is composed of a plurality of waveguides 5 arranged at different heights. Each waveguide 5 has a radiation port at its upper end and a feed port at its lower end. The radiation ports of the waveguides 5 are aligned in a planar structure, serving as the radiation ends of the waveguide array 1. The feed ports of the waveguides 5 are arranged in a non-planar, three-dimensional configuration, serving as the feed ends of the waveguide array 1. The combination of waveguides 5 at different heights increases the surface area of the feed end, improving thermal conductivity and thus enhancing heat dissipation.

[0050] In this embodiment, the cavity of each waveguide 5 is made of metal material. Metal material has good thermal conductivity, which further improves the heat dissipation capacity of the waveguide array. The height of each waveguide 5 can be adjusted according to the actual simulation results of the radiation efficiency of the phased array. In this embodiment, each waveguide 5 is preferably a ridge waveguide (the ridge waveguide opening of the waveguide is as shown in FIG. Figure 6 As shown), the size of the waveguide array 1 can be further reduced, which is beneficial to the miniaturization of the antenna. In order to achieve the conditions of suppressing grating lobes (affecting the directionality of the signal) when the array scans ±30°, the size of the antenna is limited. Specifically, the outer side length of the 96GHz waveguide antenna unit must be less than 2.08mm. The actual minimum wall thickness of the waveguide during machining is 0.15mm. Therefore, traditional waveguide antenna units are not suitable for large-angle scanning of the array. Compared with traditional rectangular waveguides, the structure of the ridge waveguide can extend the inner side length, change the current path, and reduce the cutoff frequency, thereby further improving the antenna performance. The scale of the waveguide array 1 is selected according to actual needs.

[0051] Several PCB dielectric plates 2 serve as feed adapters, positioned one-to-one at the feed ports of the waveguide 5 and bonded to the waveguide 5 via high-temperature solder paste. The internal wiring of each PCB dielectric plate 2 is a stripline. In this embodiment, two adjacent dielectric plates 2 are stacked to reduce their footprint, enabling the installation of larger PCB dielectric plates 2 and thereby increasing the power capacity of the active phased array 1. In this embodiment, the total thickness of a single PCB dielectric plate 2 is 1.1 mm.

[0052] As an example, the PCB dielectric board 2 is formed by bonding multiple layers of dielectrics. Each PCB dielectric board 2 is formed by laminating and pressing two dielectric layers together. Each dielectric layer is a high-frequency dielectric. In this embodiment, the two dielectric materials are preferably Rogers 3003 and FR-28, with relative dielectric constants of 3 and 2.8, respectively.

[0053] like Figure 6 As shown, a microstrip line 4 is provided on the upper end surface of each dielectric plate 2, and the microstrip line 4 extends to the radiation port of the corresponding waveguide 5. The microstrip line 4 is connected to the stripline inside the PCB dielectric plate 2 through a coaxial metallized hole.

[0054] The DC signal transmission process for each dielectric plate 2 is as follows: After stripline feeding, the current signal is transmitted through coaxial metallized vias to the microstrip line 4 on the PCB surface. Electromagnetic waves (TEM waves) are radiated into the waveguide 5, where they are converted into TE waves. The guided electromagnetic waves are then converted into plane waves in free space, achieving wireless signal transmission. This feeding method can further reduce the footprint of the active phased array 1, facilitating antenna miniaturization.

[0055] As an example, green oil (ie, liquid photoresist) is laid on each dielectric plate 2 at a position corresponding to the waveguide 5 , which is beneficial to the welding between the waveguide 5 and the dielectric plate 2 .

[0056] As an example, the waveguide array 1 is a square sub-array.

[0057] Example 2:

[0058] Based on the above embodiment 1, this embodiment provides a W-band active phased array, wherein the waveguide array 1 is composed of a plurality of waveguide line arrays 6 arranged laterally.

[0059] like Figure 7 As shown, each waveguide array 6 is composed of one or more waveguides 5 arranged horizontally; all waveguides 5 in the same waveguide array 6 have the same height. The waveguides 5 in adjacent waveguide arrays 6 have different heights, so that the lower end surface of the waveguide array 1 is stepped.

[0060] The lower end surface of the W-band active phased array formed by arranging the PCB dielectric board 2 at the lower part of the waveguide array 1 is also stepped as a whole.

[0061] In this embodiment, each PCB dielectric plate 2 corresponds to a waveguide wire array 6 on a one-to-one basis. This structural form can reduce the difficulty of processing the dielectric plate 2 .

[0062] In this embodiment, the lower end surface of the waveguide array is a stepped structure with a high middle and low ends. The waveguide line arrays in the waveguide array can be arranged in a 1×(2n+1) arrangement, where n is a positive integer greater than 0.

[0063] As an example, the waveguide array 1 is composed of 9 waveguide line arrays 6 arranged horizontally, among which the waveguide line array 6 located in the middle position has the highest height, and then the heights of the waveguide line arrays 6 on both sides decrease successively, and the waveguide line arrays 6 on both sides are symmetrically arranged relative to the waveguide line array 6 in the middle position.

[0064] The end face of each waveguide is square, and its side length is 1.9mm; the scale of the entire waveguide array 1 is 9×9, and the diameter is 17.1mm×17.1mm; Figure 4As shown, the lengths of each waveguide array are 1.5 mm, 2.5 mm, 3.5 mm, 4.5 mm, 5.5 mm, 4.5 mm, 3.5 mm, 2.5 mm and 1.5 mm respectively. The performance of the active phased array in this embodiment is as follows: Figures 8 to 11 As shown, the center frequency f0 = 94 GHz, the lower sideband f2 = 92 GHz, and the upper sideband f1 = 96 GHz can achieve two-dimensional (pitch and azimuth) ±30° scanning.

[0065] Figure 8 In the figure, the x-axis is frequency and the y-axis is standing wave ratio. It can be seen that the standing wave ratio in the frequency band from 92 GHz to 96 GHz is less than 2, which means that the active phased array has excellent impedance matching.

[0066] Figure 9 In the figure, the x-axis is frequency, the y-axis is normal phase gain, the dotted line is the theoretical gain value under the aperture, and the solid line is the simulated gain value under the aperture. It can be seen that the simulated gain value in the frequency band from 92 GHz to 96 GHz can reach 85% of the theoretical gain value.

[0067] Figure 10 In the figure, the x-axis is the radiation angle in the pitch dimension, and the y-axis is the gain value. The black curve is the gain value of the array in the pitch dimension of 30° scanning, the red curve is the normal gain value of the array, and the blue curve is the gain value of the pitch dimension of -30° scanning.

[0068] Figure 11 In the figure, the x-axis is the azimuth radiation angle and the y-axis is the gain value; the black curve is the array azimuth 30° scanning gain value, the red curve is the array normal gain value, and the blue curve is the azimuth -30° scanning gain value;

[0069] That is, the active phased array structure in this embodiment can achieve good impedance matching and radiation characteristics.

[0070] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A W-band active phased array, characterized in that: include: A waveguide array (1) and a plurality of PCB dielectric boards (2); The upper end surface of the waveguide array (1) is a planar structure, serving as the radiation end of the phased array (1), and the lower end surface is a non-planar three-dimensional layout, serving as the feeding end of the phased PCB array (2); A plurality of PCB dielectric plates (2) serve as feed adapter plates and are arranged on the lower end surface of the waveguide array (1).

2. The W-band active phased array according to claim 1, wherein: The waveguide array (1) is composed of a plurality of waveguides (5) arranged and combined at different heights; the upper end opening of each waveguide (5) is a radiation port, and the lower end opening is a feed port; the radiation ports of the plurality of waveguides (5) are flush, forming a radiation end of the phased array (1); the feed ports of the plurality of waveguides (5) are arranged in a non-planar three-dimensional layout, forming a feed end of the phased array (1); The PCB dielectric plates (2) are arranged in a one-to-one correspondence at the feed ports of the waveguide (5).

3. The W-band active phased array according to claim 2, wherein: Also includes: several microstrip lines (4); The microstrip lines (4) are arranged on the upper end surface of the PCB dielectric plate (2) in a one-to-one correspondence, and the microstrip lines (4) extend to the radiation port of the corresponding waveguide (5); The microstrip line (4) is connected to the strip line in the PCB dielectric plate (2) through a coaxial metallized hole.

4. The W-band active phased array according to claim 1, wherein: The waveguide array (1) is composed of a plurality of waveguide line arrays (6); The waveguide array (6) is composed of one or more waveguides (5) arranged horizontally; all waveguides (5) in the same waveguide array (6) have the same height, while the waveguides (5) in adjacent waveguide arrays (6) have different heights; The PCB dielectric plate (2) corresponds one-to-one to the waveguide line array (6).

5. The W-band active phased array according to claim 4, wherein: The lower end surface of the waveguide array (1) is a stepped structure with a high middle and low ends; The waveguide line arrays (6) in the waveguide array (1) are a 1×(2n+1) arrangement and combination, wherein n is a positive integer greater than 0.

6. The W-band active phased array according to any one of claims 1 to 5, characterized in that: The waveguide (5) is a ridge waveguide.

7. The W-band active phased array according to any one of claims 1 to 5, characterized in that: The cavity of the waveguide (5) is made of metal.

8. The W-band active phased array according to any one of claims 1 to 5, characterized in that: Two adjacent PCB dielectric plates (2) are arranged in a stacked manner.

9. The W-band active phased array according to any one of claims 1 to 5, characterized in that: The PCB dielectric plate (2) is formed by bonding multiple layers of dielectrics; each PCB dielectric plate (2) is formed by stacking and pressing two media in multiple layers.

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