Circularly polarized packaged phased-array antenna with large angle and low axial ratio

Abstract

The invention provides a large-angle low-axial-ratio circularly polarized packaged phased-array antenna, and belongs to the technical field of satellite-borne ground orbit satellite communication packaged phased-array antennas. The radiator of the antenna is all-metal, circularly polarized work of the antenna unit is realized based on a current rotation technology, and low axial ratio performance during large-angle scanning is realized under the condition of ensuring single-end feed by combining two technologies of rotation feed and parasitic loading of a uniform radiation field; meanwhile, ceramic packaging is introduced, a dielectric-free antenna sub-array module and a four-unit four-beam amplitude-phase chip are integrated into a whole to form a full-function sub-array module for packaging the phased-array antenna, the 16 full-function sub-array modules are arranged in a 4 * 4 mode, and the achieved circularly-polarized transmitting-receiving packaging phased-array antenna is used for a low-orbit satellite load scene. The packaging phased-array antenna framework has the characteristic of radiation resistance, is excellent in air tightness and heat dissipation performance, and can ensure the reliability of the packaging phased-array antenna.

Description

Technical Field

[0001] This invention belongs to the field of satellite communication packaged phased array antenna technology, and relates to circularly polarized transceiver packaged phased array antenna, specifically a large-angle, low-axis-ratio circularly polarized transceiver packaged phased array antenna for low-Earth orbit satellite communication. Background Art

[0002] In recent years, low Earth orbit (LEO) satellite communication technology has attracted widespread attention from academia and industry due to its high bandwidth and wide coverage cross-domain information transmission capabilities, which provide key technical support for the Internet of Things (IoT) and edge computing, demonstrating enormous commercial potential. As a core payload of LEO satellites, the onboard phased array antenna needs to operate in circular polarization mode and achieve large-angle, low axial ratio, high antenna efficiency, and multi-user access. Furthermore, the onboard phased array antenna must ensure stable and reliable operation in the space environment for extended periods.

[0003] The circular polarization of phased array antenna elements can be achieved through perturbation-excited degenerate modes, 90° couplers / power dividers, and direct synthesis of dual-line polarization. Using perturbation-excited degenerate modes to achieve circular polarization makes it difficult to guarantee a low axial ratio within the required operating frequency band and scanning range. Introducing 90° couplers / power dividers for circular polarization introduces additional feed losses, reducing antenna efficiency. Direct synthesis of dual-line polarization requires twice the number of transmit / receive channels compared to the previous two methods, which occupies on-chip transmit / receive channels originally used to implement the analog multi-beam phased array architecture, directly halving the number of users who can access the network simultaneously.

[0004] The packaging and integration architecture of phased array antennas includes conventional tile-type phased array antennas with pre-packaged chips combined with PCB, HDI, and other processes, as well as packaged phased array antennas where antenna elements are directly integrated with the chip. These conventional packaged chip and phased array antenna integration solutions cannot guarantee the radiation resistance, airtightness, and heat dissipation performance of the phased array antenna. In the harsh environment of space, reliability issues are prone to occur, shortening the payload's lifespan and ultimately leading to reduced satellite on-orbit time and increased scrap rate.

[0005] Constrained by the aforementioned challenges, the overall performance of spaceborne phased array antennas currently used for low-Earth orbit satellite communication is insufficient, and there is still room for improvement. Summary of the Invention

[0006] To address the problems existing in the background technology, the present invention aims to provide a large-angle, low-axial-ratio circularly polarized packaged phased array antenna. The antenna's radiator is all-metal, and it employs current-rotation technology to achieve circular polarization of the antenna elements. It combines two techniques—rotation feeding and parasitic loading to homogenize the radiation field—to achieve low axial-ratio performance during large-angle scanning while maintaining single-end feeding. Simultaneously, ceramic packaging is introduced to integrate the dielectric-free antenna subarray module with a four-element, four-beam amplitude and phase chip to form a fully functional subarray module for the packaged phased array antenna. Sixteen fully functional subarray modules are arranged in a 4×4 configuration, resulting in a circularly polarized transceiver packaged phased array antenna for use in low-Earth orbit (LEO) satellite payload scenarios. This packaged phased array antenna architecture exhibits radiation resistance, excellent hermeticity and heat dissipation performance, ensuring the reliability of the packaged phased array antenna. Ultimately, the realized circularly polarized transceiver packaged phased array antenna, used in LEO satellite payload scenarios, possesses advantages such as high radiation efficiency, large-angle, low axial-ratio, and high reliability.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] A large-angle, low-axis-ratio circularly polarized packaged phased array antenna includes several signal interfaces, a PCB motherboard, and 16 identical full-function subarray modules. The 16 identical full-function subarray modules are arranged in a 4×4 array on the upper surface of the PCB motherboard, and several signal interfaces are evenly arranged on the central axis of the lower surface of the PCB motherboard.

[0009] The full-function subarray module includes an antenna subarray module, a ceramic encapsulation housing, and a four-element four-beam amplitude and phase chip; the ceramic encapsulation housing is composed of a metal sealing ring, a lower ceramic substrate, and a bottom metal layer arranged sequentially from top to bottom; the four-element four-beam amplitude and phase chip is fixedly disposed inside the metal sealing ring and located at the center of the upper surface of the lower ceramic substrate; the antenna subarray module is fixedly disposed on the upper surface of the metal sealing ring;

[0010] The antenna subarray module includes four antenna elements. Each antenna element includes an octagonal metal patch, an L-shaped metal pillar, a metal wall, an upper ceramic substrate, a metal ground, and four triangular parasitic patches. A square ring metal wall is set around the upper surface of the upper ceramic substrate, with an L-shaped metal pillar inside. The octagonal metal patch is fixedly mounted on the upper surface of the L-shaped metal pillar, with the geometric center of the L-shaped metal pillar coinciding with the center of the octagonal metal patch. The upper surface of the metal wall is flush with the upper surface of the octagonal metal patch, ensuring a stable radiation pattern and providing shielding between antenna elements. A metal ground is set on the lower surface of the upper ceramic substrate, and the metal ground is fixedly connected to the upper surface of the metal sealing ring. The triangular parasitic patches are set on the sidewalls of the metal wall facing the L-shaped metal pillar. Each inclined side of the octagonal metal patch corresponds to a triangular parasitic patch, and the triangular parasitic patches are at the same height as the octagonal metal patch and do not contact each other. The triangular parasitic patches improve the axial ratio of the antenna subarray module during large-angle scanning.

[0011] The four antenna elements are arranged in a 2×2 array, and the feed phases of the four antenna elements are 0°, 90°, 180° and 270° in rotational order.

[0012] Furthermore, the number of signal interfaces is preferably four.

[0013] Furthermore, the length of each metal arm of the L-shaped metal column is 1 / 4 times the wavelength of the ceramic medium. When the feed current flows through the L-shaped metal structure, a 90° phase difference is formed on the two arms, thereby exciting two orthogonal linear polarization modes, achieving circular polarization operation under the premise of single-end feeding.

[0014] Furthermore, the triangular parasitic patch is preferably an isosceles right-angled triangular parasitic patch.

[0015] Furthermore, the antenna subarray module and the ceramic package housing are welded together to form a sealed cavity, achieving hermetic protection and heat dissipation performance for the four-unit four-beam amplitude and phase chip.

[0016] Furthermore, the spacing between the phased array elements of the circularly polarized transceiver package is half a wavelength in free space, satisfying the condition for grating-lobe-free scanning.

[0017] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0018] The circularly polarized transceiver packaged phased array antenna of this invention, after actual testing within the operating frequency band, demonstrates an antenna efficiency of no less than 80%, a scanning range of ±60°, an axial ratio of no more than 1dB when the beam is pointed at 0°, and an axial ratio of no more than 5dB when the beam is pointed at 60°. The packaged phased array antenna has an array size of 42mm × 42mm. Furthermore, due to the use of ceramic as the packaging material, it meets aerospace-grade standards and satisfies the requirements for long-term on-orbit operation of the payload. Attached Figure Description

[0019] Figure 1 A top view schematic diagram of the circularly polarized transceiver packaged phased array antenna of the present invention;

[0020] Figure 2 This is a cross-sectional schematic diagram of the circularly polarized transceiver packaged phased array antenna of the present invention;

[0021] Figure 3 This is a top view of the full-function subarray module of the circularly polarized transceiver packaged phased array antenna of the present invention;

[0022] Figure 4 This is a cross-sectional view of the full-function subarray module of the circularly polarized transceiver packaged phased array antenna of the present invention.

[0023] Figure 5 This is a top view of the antenna element of the circularly polarized transceiver packaged phased array antenna of the present invention;

[0024] Figure 6 This is a cross-sectional view of the antenna element of the circularly polarized transceiver packaged phased array antenna of the present invention;

[0025] Figure 7 This is a schematic diagram illustrating the effect of the triangular patch on the electric field distribution of the circularly polarized transceiver packaged phased array antenna of the present invention.

[0026] Figure 8 This is the scanning pattern of the lowest frequency point within the operating frequency band of the circularly polarized transceiver packaged phased array antenna of the present invention;

[0027] Figure 9 This is the scanning pattern of the center frequency point within the operating frequency band of the circularly polarized transceiver packaged phased array antenna of the present invention;

[0028] Figure 10 This is the scanning pattern of the highest frequency point within the operating frequency band of the circularly polarized transceiver packaged phased array antenna of this invention;

[0029] Figure 11 The scanning axis ratio within the operating frequency band of the circularly polarized transceiver packaged phased array antenna of this invention.

[0030] Reference numerals: 101-Full-function subarray module, 102-Signal interface, 201-PCB master plate, 301-Antenna element, 302-Triangular parasitic patch, 401-Four-element four-beam amplitude and phase chip, 402-Metal sealing ring, 403-Lower ceramic substrate, 404-Bottom metal layer, 501-Octagonal metal patch, 502-L-shaped metal pillar, 503-Metal wall, 601-Upper ceramic substrate, 602-Metal ground. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings.

[0032] Example 1

[0033] A top-view schematic diagram of a large-angle, low-axis-ratio circularly polarized transceiver phased array antenna for low-Earth orbit satellite communication is shown below. Figure 1 As shown, the cross-sectional schematic diagram is as follows: Figure 2 As shown, it includes 16 identical full-function sub-array modules 101, several signal interfaces 102, and a PCB motherboard 201; the 16 identical full-function sub-array modules 101 are arranged in a 4×4 array on the upper surface of the PCB motherboard 201, and several signal interfaces 102 are evenly arranged on the central axis of the lower surface of the PCB motherboard 201.

[0034] A top view of the full-function subarray module is shown below. Figure 3 As shown, the cross-sectional view is as follows Figure 4 As shown, the device includes an antenna subarray module, a ceramic encapsulation housing, and a four-element, four-beam amplitude and phase chip 401. The ceramic encapsulation housing is composed of a metal sealing ring 402, a lower ceramic substrate 403, and a bottom metal layer 404 arranged sequentially from top to bottom. The four-element, four-beam amplitude and phase chip 401 is fixedly disposed within the metal sealing ring 402 and located at the center of the upper surface of the lower ceramic substrate 403. The antenna subarray module is fixedly disposed on the upper surface of the metal sealing ring 402.

[0035] The antenna subarray module includes four antenna elements 301 and sixteen triangular parasitic patches 302. The four antenna elements are arranged in a 2×2 array configuration. A top view of each antenna element 301 is shown below. Figure 5 As shown, the cross-sectional view is as follows Figure 6As shown, the system includes an octagonal metal patch 501, an L-shaped metal pillar 502, a metal wall 503, an upper ceramic substrate 601, and a metal ground 602. An annular metal wall 503 is provided around the perimeter of the upper surface of the upper ceramic substrate 601, within which an L-shaped metal pillar 502 is disposed. Each metal arm of the L-shaped metal pillar is 1 / 4 the wavelength of the ceramic dielectric. The octagonal metal patch 501 is fixedly disposed on the upper surface of the L-shaped metal pillar 502, and the geometric center of the L-shaped metal pillar coincides with the center of the octagonal metal patch. The upper surface of the metal wall 503 is adjacent to the upper surface of the octagonal metal patch 501. The upper ceramic substrate 601 is flush with the ground plane to ensure a stable radiation pattern and to provide shielding between antenna elements. A metal ground plane 602 is provided on the lower surface of the upper ceramic substrate 601, and the metal ground plane 602 is fixedly connected to the upper surface of the metal sealing ring. A triangular parasitic patch 302 is provided on the side wall of the metal wall 503 facing the L-shaped metal column 502. The triangular parasitic patch 302 is an isosceles right-angled triangle patch, and its right angle is fixed at the right angle of the metal wall 503. Each inclined side of the octagonal metal patch is provided with a corresponding triangular parasitic patch. The triangular parasitic patch and the octagonal metal patch are at the same height and do not contact each other.

[0036] To achieve circularly polarized transceiver phased array antennas, the antenna elements also need to operate with circular polarization. This invention proposes a method for achieving circular polarization based on current rotation, specifically an L-shaped metal pillar structure. Each metal arm of the L-shaped metal pillar structure represents 1 / 4 of the wavelength in the ceramic dielectric. When the feed current flows through the L-shaped metal structure, a 90° phase difference is formed between the two structures, thereby exciting two orthogonal linear polarization modes. This achieves circular polarization under single-ended feeding conditions, ensuring a simple feeding structure.

[0037] Regarding the antenna subarray module, the feed phases of the four antenna elements are 0°, 90°, 180°, and 270° in rotational order, effectively improving the axial ratio of the antenna beam pointing at 0° within the operating frequency band. Simultaneously, it addresses the problem of deteriorating axial ratio during large-angle scanning of the antenna subarray: triangular parasitic patches are placed above the metal wall of each antenna element, forming an octagonal air cavity with the boundary of the metal wall. In other words, a total of 16 triangular parasitic patches are placed on the antenna subarray module, forming four octagonal air cavities. These parasitic patches adjust the aperture field distribution of the antenna elements, making it more uniform, thereby effectively improving the axial ratio of the antenna subarray module during large-angle scanning.

[0038] Figure 7 This is a schematic diagram showing the effect of the triangular patch on the electric field distribution of the circularly polarized transceiver packaged phased array antenna of the present invention. After loading the triangular parasitic patch, the electric field distribution is more uniform.

[0039] Figures 8 to 10The scanning patterns of the circularly polarized transceiver packaged phased array antenna of this invention are shown at the lowest frequency, center frequency, and highest frequency within the operating frequency band, including five scanning angles: -60°, -30°, 0°, -30°, and 60°. As can be seen from the figures, this circularly polarized transceiver packaged phased array antenna can cover a scanning range of ±60° within the operating frequency band. When the beam is pointed at ±60°, the antenna gain decreases by approximately -5dB compared to when the beam is pointed at 0°.

[0040] Figure 11 The curves showing the axial ratio of the circularly polarized transceiver phased array antenna of this invention as a function of frequency at five scanning angles: -60°, -30°, 0°, -30°, and 60° are presented. As can be seen from the figures, the axial ratio is no higher than 1 dB when the beam points to 0°, and no higher than 5 dB when the beam points to 60°.

[0041] The above description is merely a specific embodiment of the present invention. Any feature disclosed in this specification may be replaced by other equivalent or similar features unless otherwise specified. All disclosed features, or steps in all methods or processes, may be combined in any way except for mutually exclusive features and / or steps.

Claims

1. A large-angle, low-axial-ratio circularly polarized packaged phased array antenna, characterized in that, It includes several signal interfaces, a PCB motherboard, and 16 identical full-function sub-array modules. The 16 identical full-function sub-array modules are arranged in a 4×4 array on the upper surface of the PCB motherboard, and several signal interfaces are evenly arranged on the central axis of the lower surface of the PCB motherboard. The full-function subarray module includes an antenna subarray module, a ceramic encapsulation housing, and a four-element four-beam amplitude and phase chip; the ceramic encapsulation housing is composed of a metal sealing ring, a lower ceramic substrate, and a bottom metal layer arranged sequentially from top to bottom; the four-element four-beam amplitude and phase chip is fixedly disposed inside the metal sealing ring and located at the center of the upper surface of the lower ceramic substrate; the antenna subarray module is fixedly disposed on the upper surface of the metal sealing ring; The antenna subarray module includes four antenna elements. Each antenna element includes an octagonal metal patch, an L-shaped metal pillar, a metal wall, an upper ceramic substrate, a metal ground, and four triangular parasitic patches. A square ring metal wall is provided around the upper surface of the upper ceramic substrate, and an L-shaped metal pillar is provided inside the ring. The octagonal metal patch is fixedly provided on the upper surface of the L-shaped metal pillar, and the geometric center of the L-shaped metal pillar coincides with the center of the octagonal metal patch. The upper surface of the metal wall is flush with the upper surface of the octagonal metal patch. A metal ground is provided on the lower surface of the upper ceramic substrate, and the metal ground is fixedly connected to the upper surface of the metal sealing ring. The triangular parasitic patches are provided on the sidewall of the metal wall facing the L-shaped metal pillar. Each inclined side of the octagonal metal patch is provided with a corresponding triangular parasitic patch. The triangular parasitic patches are at the same height as the octagonal metal patch and do not contact each other. The four antenna elements are arranged in a 2×2 array, and the feed phases of the four antenna elements are 0°, 90°, 180° and 270° in rotational order.

2. The large-angle, low-axis-ratio circularly polarized packaged phased array antenna as described in claim 1, characterized in that, There are 4 signal interfaces.

3. The large-angle, low-axis-ratio circularly polarized packaged phased array antenna as described in claim 1, characterized in that, The length of each metal arm of the L-shaped metal column is 1 / 4 times the wavelength of the ceramic medium. When the feed current flows through the L-shaped metal structure, a 90° phase difference is formed on the two arms, thereby exciting two orthogonal linear polarization modes, achieving circular polarization operation under the premise of single-end feeding.

4. The large-angle, low-axis-ratio circularly polarized packaged phased array antenna as described in claim 1, characterized in that, The triangular parasitic patch is an isosceles right-angled triangular parasitic patch.

5. The large-angle, low-axis-ratio circularly polarized packaged phased array antenna as described in claim 1, characterized in that, The antenna subarray module and the ceramic package housing are welded together to form a sealed cavity, achieving hermetic protection and heat dissipation performance for the four-unit four-beam amplitude and phase chip.

6. The large-angle, low-axis-ratio circularly polarized packaged phased array antenna as described in claim 1, characterized in that, The spacing between the phased array elements of the circularly polarized transceiver package is half a wavelength in free space, which satisfies the condition of grating-lobe-free scanning.

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