Active phased array antenna

Abstract

The present invention discloses an active phased array antenna in the field of communications. The active phased array antenna includes an antenna array surface and an internal active network. The antenna array surface includes multiple antenna units evenly distributed around a circumference. The internal active network includes a power splitter / combiner module, multiple transmitting and receiving components, a wave control unit, and a power supply unit. The power splitter / combiner module is connected to the multiple transmitting and receiving components, the transmitting and receiving components are connected to the multiple antenna units, and the wave control unit is connected to the transmitting and receiving components. The active phased array antenna effectively reduces costs and can achieve 360° fast electronic scanning on the azimuth plane; it eliminates the need for a servo turntable, reduces the weight of the entire system, and saves power consumption; it overcomes the shortcomings of the planar phased array combination, such as the deterioration of indicators when scanning at large angles, and has excellent performance, low cost, and a wide range of application scenarios.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to an active phased array antenna. Background Art

[0002] Active phased array antennas have been widely used in various applications due to their advantages, including microsecond-level beam scanning, agile beam shape change, spatial power combining capabilities, and ease of conformal installation. Planar active phased array antennas, due to their mature theory, relatively simple manufacturing process, and reliable performance, have become the primary form of active phased array antenna. When an active phased array antenna needs to perform a full 360° beam scan of the airspace, there are currently two main scanning modes: one is that the active phased array antenna is installed on a servo turntable that can rotate 360° in azimuth. Through the combination of electronic scanning and mechanical scanning, it can quickly perform electronic scanning within a certain angle (generally ±45°). When the scanning angle span is large (greater than 45°), the turntable is rotated to the corresponding angle before electronic scanning. The second is when there is no servo mechanism, three or more planar active phased array antennas are spliced together in triangles or polygons on the azimuth plane. Each active phased array antenna array face is responsible for scanning the airspace at a certain angle, and the combination achieves 360° scanning coverage of the airspace in azimuth.

[0003] When an active phased array antenna performs a full 360° beam scan of the airspace through a servo turntable using a combination of electronic and mechanical scanning, the servo turntable that carries large and heavy active phased array antennas generally has a scanning cycle of at least 5 seconds per revolution; the servo turntable that carries small and light active phased array antennas can achieve a scanning speed of 1 second per revolution. When scanning over a large angle span, the angular velocity of the turntable affects the antenna's beam pointing scanning speed, and the beam switching time reaches more than several hundred milliseconds, which is still relatively slow for system applications. At the same time, the use of a servo turntable increases the weight and power consumption of the antenna platform, makes the operation complex, and reduces the reliability of the platform, resulting in a series of disadvantages. When scanning in the form of a planar phased array combination, the antenna beam has a high scanning speed, and the speed of scanning a 360° circle in the azimuth plane of the airspace can reach within tens of microseconds. However, the performance of the planar phased array antenna decreases rapidly with the increase of the beam scanning angle. Generally, when the beam scans ±60°, the antenna gain decreases by 3dB to 5dB, the beam width increases by 2 to 3 times, the sidelobe level increases by 5dB to 10dB, and the lobe shape is severely distorted. These changes directly affect the performance of the antenna in some specific angle ranges when scanning 360° in the azimuth plane.

[0004] When the active phased-control antenna is required to perform 360-degree scanning coverage in azimuth while maintaining stable antenna beam performance and fast beam scanning speed, the above two methods cannot achieve this. Summary of the Invention

[0005] The object of the present invention is to provide an active phased array antenna.

[0006] In order to achieve the above-mentioned object of the invention, an active phased array antenna of the present invention adopts the following technical solution:

[0007] An active phased array antenna comprises an antenna array surface and an internal active network, wherein the antenna array surface includes multiple antenna units evenly distributed around a circumference, and the internal active network includes a power splitter / combiner module, multiple transmitting / receiving components, a beam control unit, and a power supply unit. The power splitter / combiner module is connected to the multiple transmitting / receiving components, which are connected to the multiple antenna units. The beam control unit is connected to the transmitting / receiving components and sends beam control instructions to the transmitting / receiving components.

[0008] The power splitter / combiner module is connected to the external host and divides the signal transmitted by the external host into multiple channels and sends them to each of the transmitting and receiving components for processing, or receives the signals of each of the transmitting and receiving components and integrates the multiple channels into one and transmits them to the external host;

[0009] The transmitting and receiving component sends the processed signal to the corresponding antenna unit according to the beam control instruction, or receives and processes the signal transmitted by the corresponding antenna unit and sends the processed signal to the power splitter / combiner module;

[0010] After the antenna unit sends a signal to the target area and receives a reply signal from the target area, it is sent to the corresponding transmitting and receiving component for processing;

[0011] The power supply unit provides power to the power splitter / combiner module, the transmitting / receiving component, the beam control unit, and the antenna unit. This antenna utilizes a single pulse sum / difference system and operates in the L-band. The beam control unit controls the transmitting / receiving component to select different antenna units for transmitting or receiving signals. The circular phased array antenna allows for rapid beam scanning over the target area. Furthermore, the performance indicators of the antenna beams in different orientations remain essentially consistent, overcoming the drawback of planar phase-scanning combined technology, which suffers from significant performance degradation when subjected to large-angle electronic scanning offsets.

[0012] Furthermore, the antenna array includes 16 antenna elements, arranged in a uniform circular pattern at 22.5° intervals. The internal active network includes a power splitter / combiner module and four transmitting / receiving components, each of which is connected to four equally spaced antenna elements via radio frequency cables. Due to the circular symmetry, the active phased-control antenna maintains stable power-on performance across all azimuth angles during 360° scanning.

[0013] Furthermore, the transmitting and receiving assembly includes a first phase shifter, a one-to-two switch, a power amplifier, a circulator, a low-noise amplifier, a one-to-two power splitter, and a second phase shifter, all connected in sequence. One output end of the one-to-two power splitter is also connected to the one-to-two switch. The circulator is also connected to a one-to-four switch, and the one-to-four switch is connected to the four antenna units. Because a one-to-four switch is added to the transmitting and receiving assembly, 360° airspace coverage in the azimuth plane can be achieved by switching four transmitting and receiving assemblies. Traditional active phased antenna design methods require 16 transmitting and receiving assemblies, significantly reducing equipment costs.

[0014] Furthermore, the one-to-four switch selects the corresponding antenna unit according to the beam control instruction of the beam control unit.

[0015] Furthermore, the beam control unit includes a network chip, an ARM, and an FPGA connected in sequence. The network chip is also connected to an external host and receives host instructions. The network chip transmits information to the ARM. The ARM receives the control information transmitted by the network chip and parses and processes the control information and sends it to the FPGA. The FPGA generates corresponding working parameters according to the instructions sent by the ARM and sends them to the transmitting and receiving component to control the transmitting and receiving component to form the beam required by the external host. The ARM is also connected to an EEPROM and calls the correction data in the EEPROM chip.

[0016] Compared with the existing technology, the beneficial effects of the present invention are: effectively reducing costs while realizing 360° rapid electronic scanning on the azimuth plane; eliminating the servo turntable, reducing the weight of the entire system and saving power consumption; overcoming the shortcomings of the planar phased array combination such as the deterioration of indicators when scanning at large angles, with excellent performance, low cost, and a wide range of application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention;

[0018] Figure 2 Provide a schematic block diagram of the transmitting and receiving components;

[0019] Figure 3 This is the principle block diagram of the wave control unit;

[0020] Figure 4 Schematic diagram of antenna beam scanning. DETAILED DESCRIPTION

[0021] The present invention will be further explained below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, modifications of various equivalent forms of the present invention made by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0022] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0023] In the description of the present invention, it should be noted that the terms "vertical" and "peripheral surface" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or the orientations or positional relationships in which the inventive product is typically placed when in use. These terms are intended solely to facilitate the description of the present invention and simplify the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third," etc., are used solely for distinction and should not be construed as indicating or implying relative importance.

[0024] In addition, the term "vertical" does not mean that the component must be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0025] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0026] In the description of the present invention, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and combine different embodiments or examples described in the present invention, as well as features of different embodiments or examples, without any contradiction.

[0027] Example: Figure 1-3As shown, an active phased array antenna includes an antenna array surface and an internal active network. The antenna array surface includes 16 antenna units evenly distributed on the circumference. The antenna units are evenly arranged on the circumference at intervals of 22.5 degrees. The internal active network includes a power splitter / combiner module, four transmitting and receiving components, a beam control unit and a power supply unit. The power splitter / combiner module is connected to the four transmitting and receiving components at the same time. Each transmitting and receiving component is connected to four antenna units equidistant from each other via radio frequency cables. The beam control unit is connected to the four transmitting and receiving components and controls the four transmitting and receiving components. The power supply part stabilizes and protects the external input power and provides power supply inside the device; the transmitting and receiving components include a phase shifter 1, a one-to-two switch, a power amplifier, a circulator, a low-noise amplifier, a one-to-two power splitter, and a phase shifter 2 connected in sequence. One of the output ends of the one-to-two power splitter is also connected to the one-to-two switch, the circulator is also connected to the one-to-four switch, the one-to-four switch is connected to four antenna units equidistant from each other, and the one-to-four switch selects the corresponding antenna unit according to the wave control instruction of the wave control unit.

[0028] Phase shifter 1 and phase shifter 2 both use 6-bit RF phase shifters, the switch uses an RF switch with a switching speed of less than 100ns, the power amplifier uses a power amplifier tube with a maximum output power of 4W, the one-to-four switch uses a medium-power fast switch, the low-noise amplifier uses a low-noise field-effect transistor, and the power divider uses an RF power divider.

[0029] The sum and difference ports of the four transmitter-receiver components are connected to a power splitter / combiner module. The module uses two 1-to-4 power splitter / combiner chips, responsible for the sum and difference channels respectively. The transmit sum signal is generated by the external host and sent to a 1-to-4 power splitter / combiner, where it is equally divided into four signals and sent to each transmitter-receiver component. The sum receive signal is sent from the four transmitter-receiver components to a 1-to-4 power splitter / combiner for power combination into one signal before being sent to the external host. The difference receive signal is sent from the four transmitter-receiver components to a 1-to-4 power splitter / combiner for power combination into one signal before being sent to the host.

[0030] The beam control unit is composed of ARM, FPGA, network chip, EEPROM, etc. The beam control unit includes a network chip, ARM and FPGA connected in sequence. The network chip is also connected to the external host and receives host instructions. The network chip transmits information to the ARM. The ARM receives the control information transmitted by the network chip and parses and processes the control information and sends it to the FPGA. The FPGA generates corresponding working parameters according to the instructions sent by the ARM and sends them to the transmitting and receiving components and controls the transmitting and receiving components to form the beam required by the external host. The ARM is also connected to the EEPROM and calls the correction data in the EEPROM chip.

[0031] The specific working process and principle of the present invention:

[0032] During transmission, after the transmission sum signal of the external host is input into the antenna, it first passes through the power splitter / combiner module to divide the transmission sum signal into sum signal 1, sum signal 2, sum signal 3, and sum signal 4, and sends them to the transmitting and receiving components 1, 2, 3, and 4 respectively. After each sum signal is input into the transmitting and receiving components, it first passes through phase shifter 1 for phase shifting processing, and then passes through a one-to-two switch for signal power amplification. Finally, it is sent to the one-to-four switch through a circulator, and is sent to the selected antenna unit for transmission through the RF cable according to the wave control instruction.

[0033] Among them, the transmitting and receiving component 1 can be connected to any one of the antenna units 1, 5, 9, and 13 through a one-to-four switch selection; the transmitting and receiving component 2 can be connected to any one of the antenna units 2, 6, 10, and 14 through a one-to-four switch selection; the transmitting and receiving component 3 can be connected to any one of the antenna units 3, 7, 11, and 15 through a one-to-four switch selection; the transmitting and receiving component 4 can be connected to any one of the antenna units 4, 8, 12, and 16 through a one-to-four switch selection. In this way, the four-way transmitting and receiving signals can be sent to antenna units 1 to 4; unit 2 to unit 5; unit 3 to unit 6; ... unit 13 to unit 16; ... unit 14 to unit 1; unit 15 to unit 2; unit 16 to unit 3 through switch selection; a total of 16 combinations. Figure 4 As shown, when the scan angle is 0°, the beam control unit controls the one-to-four switches within the four transmit / receive assemblies, selecting antenna units 15, 16, 1, and 2 for operation. When the scan angle is 90°, only antenna units 3, 4, 5, and 6 need to be activated. This allows for a 22.5° scan step in the azimuth plane simply by selecting which antenna unit is active. When the antenna beam needs to scan between -11.25° and +11.25°, this is achieved by simply adjusting the phase shift value of one of the four phase shifters within the transmit / receive assemblies. Similarly, the beam synthesized by each of the four antenna units only needs to scan within ±11.25° of the normal direction. Combined with the one-to-four switches within the transmit / receive assemblies, 360° scanning coverage is achieved in the azimuth plane.

[0034] During reception, the signal in free space is received by the four antenna elements selected during transmission and then enters the four-way transmit / receive assembly via RF cables. After passing through a one-to-four switch, the signal is amplified by a low-noise amplifier (LNA) and then split into two signals using a one-to-two power splitter. Phase shifters 1 and 2 each undergo phase shifting to generate the corresponding receive sum and difference signals. The outputs of the four transmit / receive assemblies, including receive sum signals (paths 1, 2, 3, and 4) and receive difference signals (paths 1, 2, 3, and 4), are then transmitted to the power splitter / combiner module for power combination. The resulting outputs are a receive sum signal and a receive difference signal, which are then transmitted to an external host for processing. Similar to transmission, during reception, the antenna beam scans electronically by deflecting the normal direction within ±11.25°. Combined with the one-to-four switch within the transmit / receive assembly, 360° scanning coverage is achieved in the antenna azimuth plane.

[0035] The beam control unit controls the phase shift value and output amplitude of the phase shifter inside the transmitting and receiving components according to the antenna beam pointing command sent by the host.

[0036] Working process of the beam control unit: The control instructions (beam pointing information) of the external host are sent to the network chip through the RJ45 interface. The network chip uses W5300 and is connected to the ARM chip from the 16-bit parallel bus. The ARM parses the control information and calls the correction data in the EEPROM chip for processing and then sends it to the FPGA chip. The FPGA generates the corresponding working parameters (phase shift, attenuation, switch status) according to the instructions sent by the ARM and sends them to the four transmitting and receiving components through the parallel port to control the transmitting and receiving components to form the beam required by the host.

[0037] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. An active phased array antenna, comprising an antenna array and an internal active network, characterized in that: The antenna array includes 16 antenna units evenly distributed around the circumference, and the antenna units are evenly arranged around the circumference at intervals of 22.5°. The internal active network includes a power splitter / combiner module, four transmitting and receiving components, a beam control unit, and a power supply unit. The power splitter / combiner module is connected to the four transmitting and receiving components, and each of the transmitting and receiving components is connected to four equally spaced antenna units via a one-to-four switch. The beam control unit is connected to the transmitting and receiving components and sends beam control instructions to the transmitting and receiving components. The one-to-four switch selects the corresponding antenna unit according to the beam control instructions of the beam control unit, thereby achieving 360° scanning coverage of the antenna azimuth plane. The power splitter / combiner module is connected to the external host and divides the signal transmitted by the external host into multiple channels and sends them to each of the transmitting and receiving components for processing, or receives the signals of each of the transmitting and receiving components and integrates the multiple channels into one and transmits them to the external host; The transmitting and receiving component sends the processed signal to the corresponding antenna unit according to the beam control instruction, or receives and processes the signal transmitted by the corresponding antenna unit and sends the processed signal to the power splitter / combiner module; After the antenna unit sends a signal to the target area and receives a reply signal from the target area, it is sent to the corresponding transmitting and receiving component for processing; The power supply unit supplies power to the power splitter / combiner module, the transmitting and receiving components, the beam control unit and the antenna unit.

2. The active phased array antenna according to claim 1, wherein: The transmitting and receiving component includes a phase shifter 1, a one-to-two switch, a power amplifier, a circulator, a low-noise amplifier, a one-to-two power splitter, and a phase shifter 2, which are connected in sequence. One of the output ends of the one-to-two power splitter is also connected to the one-to-two switch, the circulator is also connected to the one-to-four switch, and the one-to-four switch is connected to the four antenna units.

3. The active phased array antenna according to claim 1, wherein: The beam control unit includes a network chip, an ARM and an FPGA connected in sequence. The network chip is also connected to an external host and receives host instructions. The network chip transmits information to the ARM. The ARM receives the control information transmitted by the network chip and sends the control information to the FPGA after parsing and processing. The FPGA generates corresponding working parameters according to the instructions sent by the ARM and sends them to the transmitting and receiving component to control the transmitting and receiving component to form the beam required by the external host. The ARM is also connected to an EEPROM and calls the correction data in the EEPROM chip.

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