Annular array secondary radar electric scanning antenna and system based on array multiplexing

Abstract

The invention relates to the technical field of radar antennas, in particular to a ring array secondary radar electric scanning antenna and system based on array multiplexing. The antenna comprises a plurality of radiation groups, each radiation group is provided with two radiation units, the two radiation units are connected to a radio frequency link through the same radio frequency switch, and all the radiation units are evenly distributed in the circumferential direction. The device has the advantages of being portable and convenient to install.

Description

Technical Field

[0001] This application relates to the field of radar antenna technology, specifically to a ring array secondary radar electronically scanned antenna and system based on array multiplexing. Background Technology

[0002] Secondary radar transmits a 1030MHz interrogation signal to an airborne target via a ground interrogator. The airborne target, equipped with a transponder, receives the interrogation signal and sends back a 1090MHz response signal. The ground interrogator then receives the response signal to detect the target's azimuth, range, and altitude information.

[0003] Traditional secondary radar systems mainly consist of antennas, servos, transceiver processing, and display and control. During operation, the antenna achieves 360-degree azimuth coverage through mechanical rotation via the servo system. With the widespread application of secondary radar in emergency air situation monitoring and support for important areas and temporary meeting venues, higher demands are placed on the flexibility and portability of secondary radar deployment. The antenna is a crucial component of a secondary radar system; its portability, miniaturization, and lightweight design directly affect the overall portability and flexibility of the secondary radar system, and its performance influences the surveillance power and effectiveness of the system.

[0004] Traditional secondary radar systems are complex (mainly because they require servo drive structures), and are generally installed at fixed stations or on vehicles. The antennas are large and heavy, and the requirements for installation and layout are high. Portability needs to be improved, and in some installation situations where vehicles are inconvenient to reach, the installation costs are high. Summary of the Invention

[0005] This application provides a ring array secondary radar electronically scanned antenna and system based on array multiplexing. By arranging multiple radiating elements in the circumferential direction and using an RF switch array to achieve channel switching, it eliminates the need for a servo drive structure, reduces size and weight, and improves portability.

[0006] This application is achieved through the following technical solution:

[0007] In a first aspect, this application provides a ring array secondary radar electronically scanned antenna based on array multiplexing, including multiple radiating groups, each radiating group having two radiating elements, the two radiating elements being connected to the radio frequency link through the same radio frequency switch, wherein all radiating elements are evenly distributed along the circumferential direction.

[0008] This application provides a circular array secondary radar electronically scanned antenna based on array multiplexing. By grouping every two radiating elements evenly distributed around the circumference into a group and having them jointly controlled by a single RF switch to access the RF link, it achieves channel simplification and multiplexing at the hardware level. Through a small number of RF switches and RF channels, it dynamically constructs a virtual array capable of omnidirectional electronic scanning, eliminating traditional servo mechanical rotating parts. This achieves 360-degree azimuth coverage while controlling costs. While ensuring antenna performance, this application features a compact, lightweight, low-power, and rapidly deployable design, making it particularly suitable for emergency mobile surveillance scenarios with extreme portability requirements or installation locations inaccessible by vehicle.

[0009] In some optional embodiments, the number of radiation groups is configured to be six.

[0010] In some alternative embodiments, the arrangement diameter of the radiating elements is configured to be 600 mm.

[0011] In some alternative embodiments, the radio frequency switch is configured as one of a PIN diode monolithic microwave integrated circuit, a GaAs pseudocrystalline high electron mobility transistor switch, or a microelectromechanical system cantilever beam switch.

[0012] In some alternative embodiments, the radio frequency switch is configured as a single-pole double-throw topology, with microstrip lines connected in series between the common terminal of the radio frequency switch and the two radiating elements, respectively.

[0013] In some alternative embodiments, a plurality of the radio frequency switches are configured to cause the radiation group to switch in a clockwise or counterclockwise direction.

[0014] In some optional embodiments, an omnidirectional receiving antenna is also included, positioned above the center of the radiating element arrangement, the omnidirectional receiving antenna being used for sidelobe suppression and / or ADS-B signal reception.

[0015] In some alternative embodiments, the radio frequency link performs vector addition and vector subtraction on the same pair of radiating elements to form a sum channel Σ and a difference channel Δ.

[0016] In some alternative embodiments, the sum channel Σ is formed by a power combiner; the difference channel Δ is formed by a 180° mixing ring.

[0017] Secondly, this application provides a ring array secondary radar electronically scanned antenna system based on array multiplexing, including any of the ring array secondary radar electronically scanned antennas based on array multiplexing described in the first aspect.

[0018] Compared with the prior art, this application has the following advantages and beneficial effects:

[0019] This application provides a circular array secondary radar electronically scanned antenna and system based on array multiplexing. By grouping two radiating elements evenly distributed around the circumference into a group and having them jointly controlled by a single RF switch to access the RF link, channel simplification and multiplexing are achieved at the hardware level. Through a small number of RF switches and RF channels, an omnidirectional electronically scannable virtual array is dynamically constructed, eliminating traditional servo mechanical rotating parts. This achieves 360-degree azimuth coverage while controlling costs. While ensuring antenna performance, this application features a compact, lightweight, low-power, and rapid deployment flexibility, making it particularly suitable for emergency mobile surveillance scenarios with extreme portability requirements or installation locations inaccessible by vehicle. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the exemplary embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0021] Figure 1 A simplified connection diagram of a ring array secondary radar electronically scanned antenna system based on array multiplexing provided in this application embodiment;

[0022] Figure 2 The azimuth pattern of the ring array secondary radar electronically scanned antenna based on array multiplexing provided in the embodiments of this application;

[0023] Figure 3 The elevation plane pattern of a ring array secondary radar electronically scanned antenna based on array multiplexing provided in this application embodiment. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this application are only for explaining this application and are not intended to limit this application.

[0025] Firstly, such as Figure 1 As shown, this application embodiment provides a ring array secondary radar electronically scanned antenna based on array multiplexing, including multiple radiating groups, each radiating group having two radiating elements, the two radiating elements being connected to the radio frequency link through the same radio frequency switch, wherein all radiating elements are evenly distributed along the circumferential direction.

[0026] In this embodiment, during operation, by programmatically and rapidly controlling the on / off states of each radio frequency switch, it is possible to dynamically select which radiation units on the circumference are activated and connected to the radio frequency link for signal transmission or reception at any given time. By precisely controlling the excitation sequence and timing relationship of units within different radiation groups (e.g., rapidly switching and activating different units or unit combinations in a circumferential order), a beam with a specific direction can be synthesized in space. As the activation mode moves along the circumference, the beam's direction also rotates continuously within a 360° range, thereby achieving electronic scanning without mechanical movement.

[0027] In this embodiment, although the number of physically active units may be limited (due to the number of radio frequency links), the high-speed switching of the radio frequency switch is equivalent to forming a virtual antenna aperture that can move flexibly in a circle in time. Its effect is similar to a phased array with more units, but the hardware complexity and cost are greatly reduced.

[0028] This application provides a ring array secondary radar electronically scanned antenna based on array multiplexing. By grouping two radiating elements evenly distributed around the circumference into a group and controlling them together via a single RF switch to access the RF link, it simplifies and multiplexes channels at the hardware level. Through a small number of RF switches and RF channels, it dynamically constructs a virtual array capable of omnidirectional electronic scanning, eliminating traditional servo mechanical rotating parts. This achieves 360-degree azimuth coverage while controlling costs. While ensuring antenna performance, this application features a compact, lightweight, low-power, and rapidly deployable design, making it particularly suitable for emergency mobile surveillance scenarios with extreme portability requirements or installation locations inaccessible by vehicle.

[0029] In some optional embodiments, the number of radiation groups is configured to be 6; the arrangement diameter of the radiation units is configured to be 600 mm.

[0030] In this embodiment, the number of radiating groups is specifically configured as 6 (i.e., a total of 12 radiating elements), and the arrangement diameter of all radiating elements is set to 600mm. This enables the antenna to achieve an optimal balance between electronic scanning performance, physical size, and system cost. Specifically, the 6 radiating groups can ensure azimuth beamforming capability and scanning smoothness while strictly controlling the number of required RF switches to 6, simplifying the switch network and control system, and reducing complexity and cost. The 600mm arrangement diameter is relatively compact, which allows the overall antenna aperture to be sufficient to form beam gain and azimuth resolution that meet the detection requirements in the frequency band of about 1GHz, while ensuring that the entire antenna structure is lightweight and compact, making it easy for a single person to carry or to install quickly.

[0031] In some alternative embodiments, the radio frequency switch is configured as one of a PIN diode monolithic microwave integrated circuit, a GaAs pseudocrystalline high electron mobility transistor switch, or a microelectromechanical system cantilever beam switch.

[0032] In this embodiment, the PIN diode monolithic microwave integrated circuit, GaAs pseudocrystalline high electron mobility transistor switch, or microelectromechanical system cantilever beam switch possesses characteristics such as high switching speed, low insertion loss, small size, and high reliability. These switches can precisely and quickly control the connection and disconnection of the radiating element, enabling inertial-free electronic beam scanning. These RF switches are characterized by chip-based or highly integrated design, making them suitable for applications in this embodiment that prioritize lightweight and miniaturization. They are easily integrated with the antenna radiating element and feed network, further reducing the antenna profile and overall size. This configuration ensures that the beam scanning function remains electrically stable and reliable after the removal of mechanical servo mechanisms, while also facilitating manufacturing costs, power consumption, and mass production.

[0033] In some alternative embodiments, the radio frequency switch is configured as a single-pole double-throw topology, with microstrip lines connected in series between the common terminal of the radio frequency switch and the two radiating elements, respectively.

[0034] In this embodiment, the single-pole double-throw topology matches the architecture of each radiating group containing two radiating elements. Its common terminal is directly connected to a single RF link, while the two throw terminals precisely control the access and isolation of the corresponding radiating elements. This achieves efficient and reliable control of radiating element selection with a concise circuit. The series microstrip line plays the role of impedance matching, phase adjustment, and layout optimization. It can effectively compensate for the impedance difference between the switch and the radiating element, ensuring efficient transmission of RF signals. The beam shape can be adjusted by adjusting the length of the microstrip line. This design achieves precise electronic scanning while promoting the integrated integration of the RF front-end and the antenna radiator, which helps to further reduce antenna size, reduce interconnection loss, and improve overall reliability.

[0035] In some alternative embodiments, a plurality of the radio frequency switches are configured to cause the radiation group to switch in a clockwise or counterclockwise direction.

[0036] In this embodiment, by activating the various radiation groups on the circumference in a regular and sequential manner, the system can synthesize a beam that moves smoothly and continuously in the azimuth dimension, thereby achieving stable scanning coverage of the 360° airspace without blind spots. This not only ensures the orderliness and controllability of the scanning process and avoids beam skipping or blind spots, but also simplifies the complexity of the upper-level control algorithm and improves the system's response speed and reliability. By concentrating the transmission energy and time on a few radiation units that are currently pointing (i.e., i.e., time division multiplexing), the average power consumption of the system and the peak pressure of the radio frequency link are reduced while achieving omnidirectional monitoring.

[0037] In some optional embodiments, an omnidirectional receiving antenna is also included, positioned above the center of the radiating element arrangement, the omnidirectional receiving antenna being used for sidelobe suppression and / or ADS-B signal reception.

[0038] In this embodiment, the omnidirectional receiving antenna can serve as a stealth antenna. Through real-time cancellation processing of its omnidirectional beam and the main antenna pattern, it can effectively suppress interference signals entering from the side lobes of the main antenna, thereby improving the radar's anti-interference capability and angle measurement accuracy. On the other hand, it can serve as an independent ADS-B signal receiving channel, enabling it to simultaneously monitor the 1090ES signal automatically broadcast by the aircraft. This allows it to acquire additional information such as the target's identity and location without affecting the original secondary radar interrogation-response function, thus achieving information fusion between primary radar scanning and passive listening.

[0039] In some alternative embodiments, the radio frequency link performs vector addition and vector subtraction on the same pair of radiating elements to form a sum channel Σ and a difference channel Δ.

[0040] In this embodiment, the phase difference information of the signals received by two spatially separated radiating elements is utilized: the sum channel synthesizes the main beam for target detection, ranging, and communication; while the difference channel forms a unique radiation pattern with zero on the beam axis and opposite signs on both sides. By comparing the signal amplitude or phase of the Σ and Δ channels in real time, the system can directly and in real time calculate the precise angle of the target's deviation from the beam's pointing center, achieving high-precision angle measurement within one beam dwell time. Without adding any additional radiating elements or complex feed networks, the lightweight electronically scanned antenna is endowed with single-pulse precision angle measurement capability solely through signal processing of the back-end RF link, thus ensuring that the azimuth measurement accuracy reaches the level of traditional mechanically scanned radar while eliminating mechanical servo operation.

[0041] In some alternative embodiments, the sum channel Σ is formed by a power combiner; the difference channel Δ is formed by a 180° mixing ring.

[0042] In this embodiment, the power combiner can efficiently and with low loss superimpose two signals in phase to synthesize a main beam signal for target detection and communication; while the 180° mixing ring, as a broadband, high-isolation microwave device, can precisely perform 180-degree out-of-phase vector subtraction on the two input signals to stably generate a difference beam signal for precise direction finding; both are passive devices with excellent amplitude consistency and phase stability, which can ensure that an accurate and fixed amplitude and phase relationship is established between the sum and difference channels.

[0043] Secondly, embodiments of this application provide a ring array secondary radar electronically scanned antenna system based on array multiplexing, including any of the ring array secondary radar electronically scanned antennas based on array multiplexing described in the first aspect.

[0044] In summary, the circular array secondary radar electronically scanned antenna and system based on array multiplexing provided in this application addresses the fundamental problem of the bulkiness and complexity of traditional secondary radar mechanically scanned antennas by proposing a novel lightweight omnidirectional electronically scanned antenna architecture with group multiplexing and channel sharing. It groups every two circumferentially distributed radiating elements into a single group and shares access to a unique RF link through a single RF switch (such as an SPDT switch). This achieves omnidirectional electronic scanning capability equivalent to a multi-channel phased array with a minimum number of switches and channels, eliminating the need for servo mechanical structures. Furthermore, by optimizing the number and arrangement diameter of the radiating groups, selecting highly integrated RF switch chips, adopting step-sequence switching logic, integrating omnidirectional receiving antennas, and implementing sum-difference monopulse angle measurement within a single group through passive networks (such as power combiners and 180° hybrid loops), a series of collaborative designs have been achieved. While simplifying the hardware to an extreme extent and significantly reducing cost and power consumption, it not only achieves high portability and rapid deployment, but also integrates multiple functions such as high-precision angle measurement, sidelobe suppression, and ADS-B reception on a single lightweight platform, thus achieving a balance between system complexity, performance, and overall cost.

[0045] Based on the above embodiments, a ring array secondary radar electronically scanned antenna based on array multiplexing was fabricated and simulation experiments were conducted. The operating frequency was 0.99GHz~1.13GHz, the polarization was vertical polarization, and the voltage standing wave ratio was less than 2.0. Figure 2 and Figure 3 The simulation results show that at a frequency of 1.03 GHz, the main lobe gain reaches 11.8 dBi, which is about 1–2 dB higher than that of a traditional mechanically scanned antenna. During 360° scanning, the gain fluctuation is no greater than 0.7 dB, ensuring that the azimuth measurement error is no greater than 0.3°. The sidelobe level is no greater than -12 dB, and theoretically, after combining with a top omnidirectional antenna for sidelobe cancellation, it can be reduced to below -20 dB, thus reducing the probability of interception.

[0046] The specific embodiments described above illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Although the description of this application is presented in conjunction with some embodiments, this does not mean that the features of this application are limited to this embodiment. On the contrary, the purpose of describing the application in conjunction with embodiments is to cover other options or modifications that may be derived based on the claims of this application. To provide a thorough understanding of this application, many specific details are included in the above description. This application may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of this application, some specific details will be omitted in the description. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0047] It should be noted that in this specification, similar reference numerals and letters in the above figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this application, it should be noted that unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0048] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A ring array secondary radar electronically scanned antenna based on array multiplexing, characterized in that, It includes multiple radiation groups, each radiation group having two radiation elements. These two radiation elements are connected to the radio frequency link through the same radio frequency switch, and all radiation elements are evenly distributed along the circumferential direction.

2. The ring array secondary radar electronically scanned antenna based on array multiplexing according to claim 1, characterized in that, The number of radiation groups is configured to be 6.

3. The ring array secondary radar electronically scanned antenna based on array multiplexing according to claim 1, characterized in that, The diameter of the radiating units is configured to be 600 mm.

4. The ring array secondary radar electronically scanned antenna based on array multiplexing according to claim 1, characterized in that, The radio frequency switch is configured as one of a PIN diode monolithic microwave integrated circuit, a GaAs pseudocrystalline high electron mobility transistor switch, or a microelectromechanical system cantilever beam switch.

5. The ring array secondary radar electronically scanned antenna based on array multiplexing according to claim 4, characterized in that, The radio frequency switch is configured in a single-pole double-throw topology, and microstrip lines are connected in series between the common terminal of the radio frequency switch and the two radiating units, respectively.

6. The ring array secondary radar electronically scanned antenna based on array multiplexing according to claim 1, characterized in that, The plurality of radio frequency switches are configured to switch the radiation group in a clockwise or counterclockwise direction.

7. The ring array secondary radar electronically scanned antenna based on array multiplexing according to claim 1, characterized in that, It also includes an omnidirectional receiving antenna disposed above the center of the radiating element arrangement, the omnidirectional receiving antenna being used for sidelobe suppression and / or ADS-B signal reception.

8. The ring array secondary radar electronically scanned antenna based on array multiplexing according to claim 1, characterized in that, The radio frequency link forms a sum channel Σ and a difference channel Δ by performing vector addition and vector subtraction on the same pair of radiating elements.

9. The ring array secondary radar electronically scanned antenna based on array multiplexing according to claim 8, characterized in that, The sum channel Σ is formed by a power combiner; the difference channel Δ is formed by a 180° mixing ring.

10. A ring array secondary radar electronically scanned antenna system based on array multiplexing, characterized in that, Includes the ring array secondary radar electronically scanned antenna based on array multiplexing as described in any one of claims 1 to 9.

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