A W-band digital active antenna array

Abstract

The application relates to a W-band digital active antenna array, which comprises a millimeter wave subarray plate, a bottom plate and a signal processing unit; the millimeter wave subarray plate comprises a multi-channel patch antenna array and an active circuit, the active circuit comprises a W-band TR chip and an up-down conversion chip; the bottom plate comprises a low-frequency connector, a secondary power supply and corresponding local oscillation and intermediate frequency interfaces; a radio frequency input signal is input through the interface of the bottom plate, is transferred to the millimeter wave subarray plate, is input into the conversion chip to realize up-down conversion, finally is input through the TR chip and the antenna array to realize W-band signal transceiving; the low-frequency interface of the bottom plate is connected with the signal processing unit, and control and power supply signals generated by the signal processing unit are connected to the millimeter wave subarray plate after passing through the bottom plate. The application designs a miniaturized W-band digital active array. Meanwhile, an extensible active subarray design concept is adopted, the combination of millimeter wave subarrays with different numbers is adopted, and the requirement of the number of array channels in different scenes is met.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of antenna and microwave technology, and particularly relates to a W-band digital active antenna array. BACKGROUND

[0002] W-band is one of the millimeter wave atmospheric windows, and has a wide application prospect in many fields due to its frequency between microwaves and light and advantages of both microwaves and infrared. In order to obtain higher power aperture product and more flexible beam characteristics, the active phased array system becomes the preferred antenna system in such electronic systems to meet the needs. According to the requirement of antenna beam scanning range, based on the scanning grating lobe design constraint of the array antenna, the aperture size occupied by a single antenna unit is usually limited to between half a wavelength and a wavelength of the working frequency. This makes it necessary to integrate each array antenna unit and the active transceiver channel connected thereto within a range of about half a wavelength, which poses a great challenge to the realization of the millimeter wave active array. Traditionally, the active millimeter wave array adopts a discrete device design, including filters, power dividers, mixers, ADCs, DACs and many other discrete components, and the system design is relatively complex, and the circuit scale is relatively large. The higher the frequency band is, the higher the integration requirement of the active circuit is. For E / W-band electromagnetic waves, due to the shorter wavelength (e.g., about 4-5 mm for E-band and less than 3 mm for W-band), it is difficult to realize active or digitization in such a small space. Therefore, the current research is based on a relatively large active array prototype, which still has a large gap from engineering application and commercialization. (For example: Zhang Hui, Key Technology Research of Millimeter Wave Array Imaging, Southeast University, 2016; Pang Yingying, W-band Patch Antenna and Its Array Research, University of Science and Technology of China, 2020).

[0003] The wavelength of W-band electromagnetic waves is short, and the size of the antenna array is small, and the area of the corresponding active transceiver channel is limited, making it difficult to realize active and more difficult to realize digitization. Therefore, it is necessary to design an antenna array that can meet the requirements of active and digitization. SUMMARY

[0004] To solve the existing technical problems, the present application provides a W-band digital active antenna array.

[0005] The specific content of the present application is as follows: a W-band digital active antenna array, comprising a millimeter wave subarray board, a bottom plate and a signal processing unit; the millimeter wave subarray board comprises a multi-channel patch antenna array and an active circuit, and the active circuit comprises a W-band TR chip and an up-down conversion chip; the bottom plate comprises a low-frequency connector, a secondary power supply and corresponding local oscillator and intermediate frequency interfaces.

[0006] The RF input signal is input through the interface of the base plate, transitioned to the millimeter-wave subarray, and then enters the frequency conversion chip to realize up and down frequency conversion. Finally, after passing through the TR chip and antenna array, the W-band signal is transmitted and received. The low-frequency interface of the base plate is connected to the signal processing unit. The control and power supply signals generated by the signal processing unit are connected to the millimeter-wave subarray after passing through the base plate.

[0007] Furthermore, a groove is made on the base plate, and a millimeter-wave subarray is embedded in the groove. The upper surface of the millimeter-wave subarray protrudes from the upper surface of the base plate. The signal processing unit is located in the digital board. The base plate and the digital board are interconnected by a flexible flat cable, which transmits digital control signals and power supply.

[0008] Furthermore, the millimeter-wave subarray includes a series-fed patch antenna array, with the antennas placed along the edges, and the width occupied by the subsequent active circuitry not exceeding the width of the antenna array.

[0009] Furthermore, the base plate is made of FR4 board, and the millimeter-wave subarray is made of LTCC material. The millimeter-wave subarray is embedded in the groove by conductive adhesive or large-area soldering.

[0010] Furthermore, the W-band chip integrates analog mixing, filtering, digital phase shifting, and attenuation functions, and supports pulse signal mode and frequency-modulated continuous wave signal.

[0011] Furthermore, the W-band TR chip supports master-slave working mode, and the millimeter-wave front-end can support single front-end synchronization and multi-front-end synchronization functions.

[0012] When a single front-end is working, the millimeter-wave transmitting chip is set as the master chip, and the other millimeter-wave chips are set as slave chips.

[0013] When multiple front-ends are in operation, the transmitting chip of one millimeter-wave front-end is set as the master chip, and all other millimeter-wave transceiver chips are set as slave chips. The system clock is generated by the master chip, sent to the signal processing unit for splitting, and then sent to each slave chip, the timing logic device inside the signal processing unit, and the local oscillator as the system clock. The system local oscillator is generated by the master chip, sent to an external local oscillator through an RF cable for amplification, filtering, and power division, and then transmitted to each millimeter-wave transceiver chip to achieve local oscillator synchronization.

[0014] Furthermore, when multiple front-ends are combined to form a larger-scale phased array system, the clock signal output by the signal processing unit can be used as a reference clock and sent to an external local oscillator to generate multiple coherent local oscillator signals, which are then sent to multiple millimeter-wave front-ends.

[0015] Furthermore, each millimeter-wave subarray has the same circuit configuration, and different numbers of subarrays can be flexibly combined to form arrays of different sizes. The clock, local oscillator, and data of the entire system are synchronized through synchronization circuits between the subarrays.

[0016] Furthermore, multiple signal processing units can be cascaded to complete the final signal processing in the host computer.

[0017] The W-band digital active antenna array of this invention is based on a highly integrated domestically produced W-band chip (including transceiver chip and frequency conversion chip), and a miniaturized W-band digital active array is designed. Simultaneously, it adopts a scalable active subarray design concept, and by combining varying numbers of millimeter-wave subarrays, it can meet the requirements for the number of array channels in different scenarios, i.e., it can realize MIMO or phased array operating modes, significantly improving the system's flexibility and versatility. Attached Figure Description

[0018] The specific embodiments of the present invention will be further explained below with reference to the accompanying drawings.

[0019] Figure 1 This is a schematic diagram of the configuration of the W-band active digital array of the present invention;

[0020] Figure 2 Schematic diagram of W-band millimeter-wave subarray;

[0021] Figure 3 This is a schematic diagram of a millimeter-wave TR chip.

[0022] Figure 4 This is a schematic diagram of a millimeter-wave frequency converter chip.

[0023] Figure 5 This is a schematic diagram of the installation of the base plate and the millimeter-wave subarray.

[0024] Figure 6 A schematic diagram of the expansion of multiple millimeter-wave subarrays;

[0025] Figure 7 This is a schematic diagram of multiple boards cascaded together. Detailed Implementation

[0026] Reference Figure 1 This invention provides a 16-channel W-band active digital array, comprising a millimeter-wave subarray, a base plate, and a signal processing unit. The millimeter-wave subarray is 1.6mm thick and made of LTCC (Low Temperature Ceramic) material to ensure flatness. The base plate is made of FR4 board with a 1.2mm deep groove. The millimeter-wave subarray is embedded in the groove and bonded with conductive adhesive or large-area solder. The upper surface of the millimeter-wave subarray protrudes from the upper surface of the base plate, with a height difference of approximately 0.2mm between the two plates. The signal processing unit is located on the digital board. The base plate and the digital board are interconnected via a flexible flat cable, which transmits digital control signals and power supply. One signal processing unit can support up to 10 millimeter-wave subarrays.

[0027] Reference Figure 2The millimeter-wave subarray comprises a series-fed patch antenna array and active millimeter-wave circuitry, consisting of 16 transmit / receive multiplexed antenna elements. To facilitate subarray scalability, the antennas are placed along the edges. The width occupied by the subsequent active channel circuitry does not exceed the width of the antenna array. The active circuitry mainly consists of two domestically produced 8-channel W-band TR chips and one W-band frequency converter chip.

[0028] Reference Figure 3 , Figure 4 The W-band chip integrates analog mixing, filtering, digital phase shifting, and attenuation functions (achieved by adding a phase shifting module to commercially available chips). It supports pulse signal mode and frequency-modulated continuous wave signals, with a maximum signal bandwidth of 4GHz. It is compatible with time-division multiplexing and single-transmit / single-receive operating modes. The W-band transceiver chip supports master-slave operating mode, enabling multi-chip cascading and providing scalability.

[0029] Reference Figure 5 The millimeter-wave subarray is embedded in a groove in the base plate and bonded using large-area solder or conductive adhesive. The radio frequency signals, control signals, and power supply signals on the millimeter-wave subarray are interconnected with the base plate via gold wire / gold strip bonding. To facilitate subarray scalability, the antennas are placed along the edges. The width occupied by subsequent active channel circuitry does not exceed the width of the antenna array.

[0030] The baseboard includes low-frequency and power supply connectors, power supply devices, and corresponding local oscillator and intermediate frequency (SMP) interfaces. The intermediate frequency and local oscillator signals are externally input, ranging from 5-6 GHz and 10.5-12 GHz respectively. The RF input signal enters through the SMP interface on the baseboard, passes through the microstrip lines on the baseboard, and is then transitioned to the millimeter-wave subarray via gold wire bonding. Finally, it enters the frequency conversion chip for up-conversion and down-conversion, and finally passes through the TR chip and antenna array to achieve W-band signal transmission and reception. The baseboard includes low-frequency and power supply interfaces, which are connected to the signal processing unit via flexible flat cables. The control and power supply signals generated by the signal processing unit pass through the baseboard and are connected to the millimeter-wave subarray via gold wire / gold strip bonding.

[0031] Reference Figure 6Multiple millimeter-wave subarrays can be combined to form larger-scale antenna arrays, offering scalability. Each millimeter-wave subarray has the same circuit configuration, and different numbers of subarrays can be flexibly combined to form arrays of varying sizes. Synchronization circuits between subarrays ensure clock, local oscillator, and data synchronization across the entire system. The millimeter-wave front-end provided by this invention supports single-front-end synchronization and multi-front-end synchronization. The millimeter-wave transceiver chip can be configured in master or slave modes. In single-front-end operation, the millimeter-wave transmitting chip is set as the master chip, and the remaining millimeter-wave chips are set as slave chips. In multi-front-end operation, the transmitting chip of one millimeter-wave front-end is set as the master chip, and all other millimeter-wave transceiver chips are set as slave chips. The system clock is generated by the master chip, sent to the signal processing unit for splitting, and then distributed to each slave chip, the timing logic devices within the signal processing unit, and the local oscillator source as the system clock. The system local oscillator is generated by the master chip, sent via RF cable to an external local oscillator source for amplification, filtering, and power division, and then transmitted to each millimeter-wave transceiver chip to achieve local oscillator synchronization. Meanwhile, when multiple front-ends are combined to form a larger-scale phased array system, the clock signal output by the signal processing unit can also be used as a reference clock and sent to an external local oscillator source to generate multiple coherent local oscillator signals, which are then sent to multiple millimeter-wave front-ends to achieve the purpose of local oscillator coherence in a larger-scale phased array system.

[0032] Reference Figure 7 The signal processing unit provided by this invention includes timing devices such as FPGA, ARM, SFP+ optoelectronic conversion module, DDR, and FLASH. Multiple boards can be connected to a PC via SFP+ optical ports or Gigabit Ethernet ports, enabling cascading of multiple large-scale arrays and further enhancing the scalability of the digital array. For different applications, W-band digital active arrays of varying sizes can be realized through combinations of digital subarrays of different scales. Simultaneously, the entire system can be flexibly configured in MIMO mode or phased array mode. Multiple signal processing platforms can also be cascaded, further improving the scalability of millimeter-wave arrays.

[0033] This invention relates to a W-band digital active antenna array. Based on a highly integrated domestically produced W-band chip (including transceiver and frequency conversion chips), a miniaturized W-band digital active array is designed, consisting of millimeter-wave subarrays, a base plate, and a signal processing unit. Based on the domestically produced W-band chip, the millimeter-wave subarray features miniaturization and high integration; its active transceiver circuit size is comparable to that of the antenna array. This W-band digital active array can achieve subarray-level digital transceiver, with a maximum signal bandwidth of 4GHz, supporting multiple operating modes such as pulse transceiver, single-receive, and single-transmit. Multiple millimeter-wave subarrays and the signal processing unit can be freely combined to form millimeter-wave arrays of different sizes. Simultaneously, through the master-slave chip configuration, system-wide data, clock, and local oscillator synchronization is achieved. Through the signal processing unit, this digital active array can be configured for MIMO and phased array operation modes, offering high flexibility and versatility, and has significant application value in many fields such as foreign object detection, security imaging, and automotive / helicopter collision avoidance.

[0034] Many specific details have been set forth in the foregoing description to provide a thorough understanding of the present invention. However, the above description is merely a preferred embodiment of the present invention, and the present invention can be implemented in many other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed above. Furthermore, any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, using the methods and techniques disclosed above, without departing from the scope of the present invention. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A W-band digital active antenna array, characterized in that: It includes a millimeter-wave subarray, a base plate, and a signal processing unit; the millimeter-wave subarray includes a multi-channel patch antenna array and active circuitry, including a W-band TR chip and up / down conversion chips; the base plate includes a low-frequency connector, a secondary power supply, and corresponding local oscillator and intermediate frequency interfaces; The intermediate frequency (IF) and local oscillator (LO) signals are input externally. The radio frequency (RF) input signal is input through the IF interface on the baseboard, passes through the microstrip line on the baseboard, and is then transitioned to the millimeter-wave subarray via gold wire bonding. It then enters the frequency conversion chip to achieve up and down conversion, and finally passes through the TR chip and antenna array to realize W-band signal transmission and reception. The low-frequency interface on the baseboard is connected to the signal processing unit. The control and power supply signals generated by the signal processing unit are connected to the millimeter-wave subarray after passing through the baseboard. A groove is made on the base plate, and a millimeter-wave subarray is embedded in the groove. The upper surface of the millimeter-wave subarray protrudes from the upper surface of the base plate. The signal processing unit is set in the digital board. The base plate and the digital board are interconnected by a flexible flat cable, which transmits digital control signals and power supply. The millimeter-wave subarray includes a series-fed patch antenna array, with all antennas placed along the edges, and the width occupied by the subsequent active circuitry does not exceed the width of the antenna array. W-band TR chips support master-slave working mode, and millimeter-wave front-ends can support single front-end synchronization and multi-front-end synchronization functions. When a single front-end is working, the millimeter-wave transmitting chip is set as the master chip, and the other millimeter-wave chips are set as slave chips. When multiple front-ends are in operation, one of the millimeter-wave front-end transmitting chips is set as the master chip, and all other millimeter-wave transceiver chips are set as slave chips. The system clock is generated by the master chip, sent to the signal processing unit for splitting, and then sent to each slave chip, the timing logic device inside the signal processing unit, and the local oscillator as the system clock. The system local oscillator is generated by the master chip, sent to an external local oscillator through an RF cable for amplification, filtering, and power division, and then transmitted to each millimeter-wave transceiver chip to achieve local oscillator synchronization. When multiple front-ends are combined to form a larger-scale phased array system, the clock signal output by the signal processing unit can be used as a reference clock and sent to an external local oscillator to generate multiple coherent local oscillator signals, which are then sent to multiple millimeter-wave front-ends.

2. The W-band digital active antenna array according to claim 1, characterized in that: The base plate is made of FR4 board, and the millimeter-wave subarray is made of LTCC material. The millimeter-wave subarray is embedded in the groove by conductive adhesive or large-area solder.

3. The W-band digital active antenna array according to claim 1, characterized in that: The W-band chip integrates analog mixing, filtering, digital phase shifting, and attenuation functions, and supports pulse signal mode and frequency-modulated continuous wave signal.

4. The W-band digital active antenna array according to claim 1, characterized in that: Each millimeter-wave subarray has the same circuit configuration. Different numbers of subarrays can be flexibly combined to form arrays of different sizes. The clock, local oscillator, and data of the entire system are synchronized through a synchronization circuit between the subarrays.

5. The W-band digital active antenna array according to claim 1, characterized in that: Multiple signal processing units can be cascaded to complete the final signal processing in the host computer.

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