Receiving digital phased array antenna calibration method

Abstract

The invention discloses a calibration method for receiving a digital phased-array antenna, which comprises the following steps of: generating one path of signal as a reference signal by adopting a sampling DBF unit FPGA (Field Programmable Gate Array) itself, opening antenna array element channel signals in a beam pointing normal direction in a far-field test environment, and performing synchronous frequency mixing on each array element channel signal and the reference signal, and finally, the relative phase difference Phase of each antenna array element channel is obtained. According to the method, the complexity of the radio frequency assembly is reduced, and the product cost is reduced; regional calibration can be carried out on a large-scale receiving digital phased-array antenna, and the distance requirement of far-field calibration is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of calibration of digital phased array antennas, and in particular to a calibration method for a receiving digital phased array antenna. Background Art

[0002] Traditional receiving digital phased array calibration methods include internal calibration and external calibration. Internal calibration requires the RF component to provide an internal calibration coupling port, which increases the cost and complexity of the RF component unit. External calibration requires a large far-field calibration site for large digital phased arrays, which greatly reduces the scope of darkroom selection. In order to solve the above problems, it is proposed to use the sampling DBF unit FPGA itself to generate a signal as a reference signal and perform calibration in a far-field test environment. If the array surface is large, the array surface can be divided into multiple sub-arrays for calibration. Summary of the invention

[0003] The object of the present invention is to provide a receiving digital phased array antenna calibration method to solve the technical problem of insufficient existing calibration sites.

[0004] To achieve the above purpose, the present invention adopts the following technical solutions: A receiving digital phased array antenna calibration method adopts a sampling DBF unit FPGA to generate a signal as a reference signal. In a far-field test environment, the beam pointing normal opens the antenna array element channel signal, and each array element channel signal is synchronously mixed with the reference signal to finally obtain the relative phase difference △Phase of each antenna array element channel.

[0005] The reference signal is generated by the DDS inside the sampling DBF unit FPGA, and the clock for generating the reference signal is the same as the clock of the RF component.

[0006] The antenna array element channel is opened to receive the calibration signal when the beam points to the normal direction and the center of the working array area is aligned with the calibration probe.

[0007] The relative phase difference value △Phase of each antenna array element channel is the integral of the residual frequency after the channel signal of each antenna array element is synchronously mixed with the reference signal.

[0008] Compared with the prior art, the present invention has the following advantages: a receiving digital phased array calibration method is invented, which reduces the complexity of radio frequency components and reduces product costs; large receiving digital phased array antennas can be calibrated in divided areas, reducing the distance requirement for far-field calibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a principle block diagram of the receiving digital phased array antenna calibration method of the present invention. DETAILED DESCRIPTION

[0010] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0011] like Figure 1 As shown in the figure, a receiving digital phased array antenna calibration method adopts a sampling DBF unit FPGA to generate a signal as a reference signal. In a far-field test environment, the beam pointing normal opens the antenna array element channel signal, and each array element channel signal is synchronously mixed with the reference signal to finally obtain the relative phase difference value △Phase of each antenna array element channel.

[0012] The reference signal 1 is generated by the DDS inside the sampling DBF unit FPGA, and the clock for generating the reference signal is the same as the clock of the RF component. When the beam is pointing in the normal direction and the center of the working array area is aligned with the calibration probe, the antenna array channel is opened to receive the calibration signal. The relative phase difference △Phase of each antenna array channel is the integral of the residual frequency after the synchronous mixing of each antenna array channel signal and the reference signal.

[0013] The digital receiving phased array antenna calibration of the present invention can realize molecular array calibration. From the perspective of function realization, calibration site selection, system complexity and cost analysis, this calibration method is the best method for digital receiving phased arrays. This method greatly reduces the required calibration distance and reduces system complexity.

[0014] The above is a preferred embodiment of the present invention. For ordinary technicians in this field, according to the teachings of the present invention, without departing from the principles and spirit of the present invention, changes, modifications, substitutions and variations made to the implementation methods are still within the scope of protection of the present invention.

Claims

1. A receiving digital phased array antenna calibration method, characterized in that: The sampling DBF unit FPGA itself generates a signal as a reference signal. In the far-field test environment, the beam pointing normal opens the antenna array element channel signal. Each array element channel signal is synchronously mixed with the reference signal, and finally the relative phase difference △Phase of each antenna array element channel is obtained.

2. A receiving digital phased array antenna calibration method according to claim 1, characterized in that: The reference signal is generated by the DDS inside the sampling DBF unit FPGA, and the clock for generating the reference signal is the same as the clock of the RF component.

3. The receiving digital phased array antenna calibration method according to claim 1, characterized in that: The antenna array element channel is opened to receive the calibration signal when the beam points to the normal direction and the center of the working array area is aligned with the calibration probe.

4. The receiving digital phased array antenna calibration method according to claim 1, characterized in that: The relative phase difference value △Phase of each antenna array element channel is the integral of the residual frequency after the channel signal of each antenna array element is synchronously mixed with the reference signal.

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