Vehicle-mounted satellite phased-array antenna and beam forming method thereof

Abstract

The invention relates to the technical field of wireless communication, and provides a vehicle-mounted satellite phased-array antenna and a beam forming method thereof, and the phased-array antenna comprises a plurality of antenna units and T / R assemblies which are correspondingly connected. The feed network is used for distributing signals from the beam forming network to each T / R component; and the beam forming network is used for calculating and distributing a phase to each T / R component, and adopting an adaptive beam forming algorithm to control the direction of a beam by adjusting the phase, so that the beam points to a required satellite or other targets. The phased-array antenna can form a plurality of transmitting wave beams and receiving wave beams with different directions through wave beam conversion in a repetition period, has rapid scanning agility capability, can change an antenna pattern function or an antenna wave beam shape through adjusting signal amplitude and phase in each unit channel in the phased-array array, and improves the antenna performance. The reliability is improved by omitting a mechanical driving system, and even if some nodes are damaged, the use of the whole function is not affected.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and more specifically, to a vehicle-mounted satellite phased array antenna and its beamforming method. Background Technology

[0002] With the rapid development of wireless communication technology, phased array antennas have been widely used in modern communication systems due to their high flexibility, fast beam scanning capability, and precise beam control. However, traditional phased array antennas have some shortcomings in practical applications, especially in vehicle environments. First, traditional phased array antennas typically use mechanical drive systems to adjust the beam direction. This mechanical adjustment method has a slow response speed and is easily affected by environmental factors, leading to unstable beam pointing. Furthermore, in vehicle environments, the mobility and complex, ever-changing usage scenarios exacerbate this instability. Second, the beamforming algorithms of traditional phased array antennas often lack adaptive capabilities, making it difficult to cope with dynamically changing signal environments. In actual communication, the signal environment is constantly changing due to various factors, and traditional antennas struggle to adjust the beam in real time to adapt to these changes, thus affecting communication quality and system performance. In addition, traditional phased array antennas have relatively low reliability. Due to their complex mechanical structure and numerous moving parts, they are prone to system failure due to wear, malfunctions, and other problems. In vehicle environments, reliability issues can lead to severe communication interruptions, affecting vehicle navigation, monitoring, and other functions. Summary of the Invention

[0003] In view of this, this invention proposes a vehicle-mounted satellite phased array antenna and its beamforming method. It employs electronic control of the beam direction, eliminating the need for a mechanical drive system, thereby improving the system's response speed and stability. Using an adaptive beamforming algorithm, the antenna can adjust the beam in real time according to changes in the signal environment, enhancing the system's adaptability and reliability. Furthermore, this antenna system also features multi-beamforming and rapid scanning capabilities, enabling the formation of multiple beams pointing in different directions simultaneously, improving communication efficiency and anti-interference capabilities.

[0004] To achieve the above objectives, the present invention proposes a vehicle-mounted satellite phased array antenna, characterized in that it comprises: Several antenna elements, each of which is a small transmit / receive module, are responsible for transmitting or receiving radio waves. The direction of the beam is controlled by adjusting the phase of each antenna element, and the conversion between radio frequency signals and spatial electromagnetic waves is realized through the antenna elements. Several T / R components are used to convert electrical signals into radio waves for transmission or radio waves into electrical signals for reception, and each T / R component is connected to an antenna unit. The feed network is used to distribute signals from the beamforming network to the individual T / R components, ensuring that each antenna element receives a signal with the correct phase. A beamforming network is used to calculate and assign phase to each T / R component, and an adaptive beamforming algorithm is used to control the direction of the beam by adjusting the phase, so that the beam is pointed at the desired satellite or other target.

[0005] Furthermore, it also includes the power supply system, structure, and thermal control system; The power system is used to provide stable power to all components, ensuring that the system can operate normally under various working conditions; In the aforementioned structure and thermal control system, the structural system provides physical support to ensure the stability and durability of the antenna system; the thermal control system manages the temperature of the antenna system to prevent overheating.

[0006] Furthermore, the beamforming network includes a beamforming module and an anti-interference module; The beamforming module is used to change the antenna pattern function or antenna beam shape by adjusting the signal amplitude and phase in each cell channel of the phased array; the anti-interference module is used to concentrate the power of multiple radiating cells to form a high-power mode, or to improve anti-interference capability by adaptively controlling the energy and main lobe gain to transmit the required energy in different directions.

[0007] Furthermore, the signal transmission process of the vehicle-mounted satellite phased array antenna includes: The radio frequency signal enters the T / R component through a 1-to-2 power divider. After being split by a switch, the radio frequency signal is fed into a driver amplifier for amplification and output. After being split into 1-to-4 power dividers, it is fed into the T / R channel. The amplitude and phase are controlled by digital attenuators and digital delay chips. After being amplified by a three-stage amplifier, it is fed into the antenna array through the radio frequency SMP interface for transmission output.

[0008] Furthermore, the signal reception process of the vehicle-mounted satellite phased array antenna includes: After receiving the radio frequency signal, the antenna array inputs it into the T / R radio frequency channel. After being amplified by two stages of low noise amplifiers, the signal passes through a digital attenuator and a digital delay chip to control the amplitude and phase. It then enters a four-in-one power combiner. After being combined, it is amplified by a driving low noise amplifier and then enters a two-in-one power combiner. Finally, it is output to the frequency conversion channel through a switch.

[0009] The present invention further proposes the above-mentioned phased array antenna beamforming method, characterized in that it includes: The antenna array receives signals from different directions, and each antenna element converts the received radio waves into electrical signals through a T / R component; The received signal is first amplified, filtered and digitized, and the preprocessed signal is sent to a beamforming network for further processing. The initial weights, convergence criteria, and step size parameters are set. The least mean square algorithm is used to update the weights based on the received signal to minimize the output power of the desired signal or maximize the signal-to-noise ratio. The updated weights are then applied to the beamforming network to adjust the phase and amplitude of each antenna element. In a dynamically changing environment, an adaptive beamforming algorithm is used to adjust the weights in real time according to changes in the signal environment.

[0010] Furthermore, the least mean square algorithm updates the weights as shown in the following equation:

[0011] in, It is the target weight vector. It is the current weight vector. It is the step size factor. It is an error signal. It is the input signal vector.

[0012] Furthermore, the adaptive beamforming algorithm includes: using mean square error to measure the difference between the desired signal and the actual output signal; calculating the output signal based on the current weights in each iteration, calculating the error and the rate of change of error; and updating the weights by adjusting the step size factor according to the gradient direction.

[0013] Furthermore, the process of updating weights by adjusting the step size factor according to the gradient direction includes: The positive direction of the gradient is taken as the direction in which the error increases the fastest, and the negative direction of the gradient is taken as the direction in which the error decreases the fastest. Based on the gradient direction, the step size factor is decreased when the error decreases and increased when the error increases, and the step size factor is gradually decreased as the number of iterations increases.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: Multi-beamforming and fast scanning: Phased array antennas can form multiple transmit and receive beams pointing to different directions within one repetition cycle by switching beams. These beams can be independent of each other and have fast scanning and agility capabilities. Beamforming, by adjusting the signal amplitude and phase in each cell channel of a phased array, can change the antenna pattern function or the shape of the antenna beam. It has strong anti-interference capability. The phased array antenna can concentrate the power of multiple radiating elements to form a high-power mode. It can also transmit the required energy in different directions by adaptively controlling the energy and main lobe gain, thereby improving its anti-interference capability. High reliability: Because phased array radar eliminates the mechanical drive system of the entire antenna, its reliability is very high. Even if some nodes are damaged, it will not affect the use of the overall function. Even if 10% of the hundreds or thousands of array elements are damaged, the phased array radar can still be used. Attached Figure Description

[0015] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. In the drawings: Figure 1 This is a schematic diagram of the vehicle-mounted satellite phased array antenna structure in an embodiment of the present invention; Figure 2 This is a schematic diagram of beamforming for a vehicle-mounted satellite phased array antenna in an embodiment of the present invention. Detailed Implementation

[0016] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0017] This embodiment proposes a vehicle-mounted satellite phased array antenna that electronically controls the beam direction. The antenna system consists of multiple antenna elements, and the beam direction is controlled using phased array technology, such as... Figure 1 As shown, its specific structure includes: Antenna elements, each a small transmit / receive module, are responsible for transmitting or receiving radio waves. The beam direction can be controlled by adjusting the phase of each antenna element, and each antenna element is connected to a T / R assembly. The conversion between radio frequency signals and spatial electromagnetic waves is achieved through antenna elements, and their operating bandwidth and radiation efficiency are crucial to the design of the entire phased array system.

[0018] The T / R module, or Transmit / Receive module, is responsible for converting electrical signals into radio waves for transmission or radio waves into electrical signals for reception. This module is a key component of active phased array radar, determining the beamforming, direction finding accuracy, and system stability of the transmitted signal.

[0019] The feed network is responsible for distributing signals from the beamforming network to each T / R component, ensuring that each antenna element receives a signal with the correct phase, thereby achieving precise beam control.

[0020] The beamforming network is the control center of the entire system. It is responsible for calculating and allocating the correct phase to each T / R component, realizing the amplitude and phase distribution required by each element of the phased array antenna during beam scanning. By adjusting the phase, the beamforming network can control the direction of the beam to point it at the desired satellite or other target.

[0021] The power supply system provides stable power to all components, ensuring that the system can operate normally under various working conditions.

[0022] The structure and thermal control system are as follows: the structural system provides physical support to ensure the stability and durability of the antenna system; the thermal control system manages the temperature of the antenna system to prevent overheating and ensure that the system can work stably in various environments.

[0023] As a preferred embodiment, the working principle of the proposed vehicle-mounted satellite phased array antenna includes the following steps: The beamforming network performs beam scanning, calculating the phase of each antenna element as needed, and transmitting the calculated phase information to the T / R (Transmitter / Receive) module via a feed network. The T / R module adjusts the transmit or receive phase of the antenna elements based on the received phase information, thereby achieving electronic beam scanning. The received signal is converted into an electrical signal by the T / R module and then further amplified and filtered by the beamforming network. Throughout this process, a stable power supply system provides stable power to all components, ensuring normal operation under various working conditions. Structural and thermal control systems ensure stable operation of the antenna system in different environments.

[0024] like Figure 2 As shown, the ultra-wideband tightly coupled active phased array antenna system developed in this embodiment has an instantaneous operating bandwidth that can cover the entire frequency band of the active phased array antenna system. During transmission, the radio frequency signal enters the 8-channel T / R module through a 1-to-2 power divider. After being split by a switch, the signal is fed into a driver amplifier for amplification and output. Then, after being split into 1-to-4 power dividers, it is fed into the T / R channel. The amplitude and phase are controlled by digital attenuators and digital delay chips. After being amplified by a three-stage amplifier, it is fed into the antenna array through the radio frequency SMP interface for transmission output.

[0025] Similarly, during reception, after the antenna array receives the radio frequency signal, it is input into the T / R radio frequency channel. After being amplified by two stages of low noise amplifiers, the amplitude and phase are controlled by digital attenuators and digital delay chips. The signal then enters a four-in-one power combiner. After being combined, it is amplified by a driving low noise amplifier and then enters a two-in-one power combiner. After being combined, it is output to the frequency conversion channel through a switch.

[0026] Based on the above vehicle-mounted satellite phased array antenna structure, this embodiment further proposes a beamforming method for the antenna, employing an adaptive beamforming algorithm to achieve precise control of the antenna beam, specifically including the following steps: Step 1: Signal Acquisition First, the antenna array receives signals from different directions, and each antenna element converts the received radio waves into electrical signals through a T / R component.

[0027] Step 2: Signal Preprocessing The received signal is first amplified, filtered, and digitized. The preprocessed signal is then sent to a beamforming network for further processing.

[0028] Step 3: Adaptive Algorithm Initialization Before starting the adaptive beamforming algorithm, initialization settings are required, including setting initial weights, convergence criteria, and step size parameters. The initial weights can be uniformly distributed or set based on prior knowledge.

[0029] Step 4: Weight Update The Least Mean Square (LMS) algorithm is employed to continuously update weights based on the received signal, aiming to minimize the output power of the desired signal or maximize the signal-to-noise ratio. The LMS algorithm is a simple and computationally efficient adaptive algorithm suitable for real-time systems. Weights are updated by minimizing the mean square error of the output signal. The update formula for the LMS algorithm is shown below:

[0030] in, It is the current weight vector. It is the step size factor. It is an error signal. It is the input signal vector.

[0031] Step 5: Beamforming The updated weights are applied to the beamforming network to adjust the phase and amplitude of each antenna element. In this way, the beam of the antenna array is directed in the direction of the desired signal while suppressing interference signals.

[0032] Step 6: Algorithm Convergence The adaptive algorithm gradually converges during the iteration process, meaning the magnitude of weight updates gradually decreases until a preset convergence criterion is reached. After convergence, the algorithm maintains the current weight settings and restarts the iteration process based on changes in the environment.

[0033] Step 7: Real-time adjustment In a dynamically changing environment, the adaptive beamforming algorithm adjusts the weights in real time according to changes in the signal environment. This capability is one of the main advantages of the adaptive beamforming algorithm. During this process, the system continuously monitors the received signal strength, frequency, direction of arrival, and interference. Based on the above information, it calculates the signal-to-noise ratio and signal quality indicators, and evaluates the performance of the antenna system under the current beam direction in real time. When a performance degradation or environmental change is detected, the adaptive algorithm recalculates the weights based on the new signal characteristics, uses a step size factor to optimize the algorithm parameters, and continuously updates the weights to minimize errors or maximize the desired performance indicators.

[0034] Specifically, firstly, this embodiment uses mean squared error to measure the difference between the expected signal and the actual output signal. In each iteration, the output signal is calculated based on the current weights, and the value of the performance criterion, i.e., the error, is calculated. The gradient of the performance criterion with respect to the weights is also calculated, i.e., the rate of change of the performance criterion. The gradient points in the direction of the fastest increase in the performance criterion; therefore, the negative direction of the gradient is the direction of the fastest decrease in the performance criterion. Finally, the weights are updated based on the gradient and by adjusting the step size factor.

[0035] In a preferred embodiment, the step size factor is dynamically adjusted according to the convergence of the algorithm. When the error decreases as described above, the step size factor is reduced to improve stability, and when the error increases as described above, the step size factor is increased to accelerate the convergence speed. In addition, as the number of iterations increases, the step size factor is gradually reduced, so that a larger step size factor is used in the early stage of the iteration to quickly approach the optimal solution, and then the step size factor is reduced in the later stage of the iteration to finely adjust the weights, thereby achieving precise control of the beam direction.

[0036] The key technologies of the phased array antenna proposed in this embodiment mainly include RF and digital hybrid PCB, analog and digital hybrid beamforming, and domestic RF and baseband platforms. The key technical points involved are as follows: a) Analog and digital hybrid beamforming Antenna design software: Antenna structure design, parameter optimization and performance evaluation are carried out using electromagnetic simulation software such as HFSS, CST and FEKO.

[0037] Array antenna design: Design various types of array antennas, including linear arrays, planar arrays, conformal arrays, etc., and optimize their radiation characteristics.

[0038] Beamforming algorithm: An adaptive beamforming algorithm is used to achieve precise control of the antenna beam.

[0039] Classical phased array antennas typically use phase shifters as the control element for beam scanning. However, phase shifters are frequency-sensitive devices, and the same phase shift results in different time delays at different frequencies. The bandwidth of a phased array antenna is mainly limited by the offset of the antenna beam pointing (spatial dispersion of the synthesized beam) and the antenna aperture transition time (temporal dispersion of the signal waveform). The phased array control proposed in this embodiment overcomes the above-mentioned defects.

[0040] b) Radio frequency and digital hybrid antenna Microwave circuit design: Design microwave circuits such as antenna feed networks and power distribution networks, and select appropriate microwave devices.

[0041] Antenna fabrication technology: Master various antenna fabrication processes, including metal processing, dielectric processing, and printed circuit board fabrication.

[0042] Integration technology: This includes the integration of antennas with other electronic devices, and further includes the integration of antennas with radio frequency front-ends and the integration of antennas with digital signal processors.

[0043] In summary, this invention has several advantages: This embodiment employs phased array antenna technology and a high-density integrated design, enabling the construction of the shortest transmit and receive links for multi-channel antennas. It utilizes a multi-interface integrated beam control module with built-in multiple sets of beam direction adjustment data, facilitating rapid application in various environments. Equipped with a multi-functional interface cable, it flexibly integrates with external devices to build a synchronous control system, facilitating the development and testing of wireless links. In a vehicle environment, it provides more stable and reliable communication performance, meeting the demands of modern wireless communication systems for high-performance antennas.

[0044] Multi-beamforming and fast scanning: Phased array antennas can form multiple transmit and receive beams pointing to different directions within one repetition cycle by switching beams. These beams can be independent of each other and have fast scanning and agility capabilities. Beamforming, by adjusting the signal amplitude and phase in each cell channel of a phased array, can change the antenna pattern function or the shape of the antenna beam. It has strong anti-interference capability. The phased array antenna can concentrate the power of multiple radiating elements to form a high-power mode. It can also transmit the required energy in different directions by adaptively controlling the energy and main lobe gain, thereby improving its anti-interference capability. High reliability: Because phased array radar eliminates the mechanical drive system of the entire antenna, its reliability is very high. Even if some nodes are damaged, it will not affect the use of the overall function. Even if 10% of the hundreds or thousands of array elements are damaged, the phased array radar can still be used.

[0045] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0046] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the scope of the technology disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention. All should be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A vehicle-mounted satellite phased array antenna, characterized in that, include: Several antenna elements, each of which is a small transmit / receive module, are responsible for transmitting or receiving radio waves. The direction of the beam is controlled by adjusting the phase of each antenna element, and the conversion between radio frequency signals and spatial electromagnetic waves is realized through the antenna elements. Several T / R components are used to convert electrical signals into radio waves for transmission or radio waves into electrical signals for reception, and each T / R component is connected to an antenna unit. The feed network is used to distribute signals from the beamforming network to the individual T / R components, ensuring that each antenna element receives a signal with the correct phase. A beamforming network is used to calculate and assign phase to each T / R component, and an adaptive beamforming algorithm is used to control the direction of the beam by adjusting the phase, so that the beam is pointed at the desired satellite or other target.

2. The vehicle-mounted satellite phased array antenna according to claim 1, characterized in that, It also includes the power supply system, structure, and thermal control system; The power system is used to provide stable power to all components, ensuring that the system can operate normally under various working conditions; In the aforementioned structure and thermal control system, the structural system provides physical support to ensure the stability and durability of the antenna system; the thermal control system manages the temperature of the antenna system to prevent overheating.

3. The vehicle-mounted satellite phased array antenna according to claim 1, characterized in that, The beamforming network includes a beamforming module and an anti-interference module; The beamforming module is used to change the antenna pattern function or antenna beam shape by adjusting the signal amplitude and phase in each cell channel of the phased array; the anti-interference module is used to concentrate the power of multiple radiating cells to form a high-power mode, or to improve anti-interference capability by adaptively controlling the energy and main lobe gain to transmit the required energy in different directions.

4. The vehicle-mounted satellite phased array antenna according to claim 1, characterized in that, The signal transmission process of the vehicle-mounted satellite phased array antenna includes: The radio frequency signal enters the T / R component through a 1-to-2 power divider. After being split by a switch, the radio frequency signal is fed into a driver amplifier for amplification and output. After being split into 1-to-4 power dividers, it is fed into the T / R channel. The amplitude and phase are controlled by digital attenuators and digital delay chips. After being amplified by a three-stage amplifier, it is fed into the antenna array through the radio frequency SMP interface for transmission output.

5. The vehicle-mounted satellite phased array antenna according to claim 1, characterized in that, The signal reception process of the vehicle-mounted satellite phased array antenna includes: After receiving the radio frequency signal, the antenna array inputs it into the T / R radio frequency channel. After being amplified by two stages of low noise amplifiers, the signal passes through a digital attenuator and a digital delay chip to control the amplitude and phase. It then enters a four-in-one power combiner. After being combined, it is amplified by a driving low noise amplifier and then enters a two-in-one power combiner. Finally, it is output to the frequency conversion channel through a switch.

6. A beamforming method for a phased array antenna, characterized in that, include: The antenna array receives signals from different directions, and each antenna element converts the received radio waves into electrical signals through a T / R component; The received signal is first amplified, filtered and digitized, and the preprocessed signal is sent to a beamforming network for further processing. The initial weights, convergence criteria, and step size parameters are set. The least mean square algorithm is used to update the weights based on the received signal to minimize the output power of the desired signal or maximize the signal-to-noise ratio. The updated weights are then applied to the beamforming network to adjust the phase and amplitude of each antenna element. In a dynamically changing environment, an adaptive beamforming algorithm is used to adjust the weights in real time according to changes in the signal environment.

7. The beamforming method according to claim 6, characterized in that, The least mean square algorithm updates the weights as shown in the following formula: ， in, It is the target weight vector. It is the current weight vector. It is the step size factor. It is an error signal. It is the input signal vector.

8. The beamforming method according to claim 6, characterized in that, The adaptive beamforming algorithm includes: using mean square error to measure the difference between the desired signal and the actual output signal; in each iteration, calculating the output signal based on the current weights, calculating the error and the rate of change of error; and updating the weights by adjusting the step size factor according to the gradient direction.

9. The beamforming method according to claim 8, characterized in that, The process of updating weights by adjusting the step size factor according to the gradient direction includes: The positive direction of the gradient is taken as the direction in which the error increases the fastest, and the negative direction of the gradient is taken as the direction in which the error decreases the fastest. Based on the gradient direction, the step size factor is decreased when the error decreases and increased when the error increases, and the step size factor is gradually decreased as the number of iterations increases.

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