Method and device for measuring phase nonlinearity of digital phased array receiving channel

Abstract

The invention discloses a method and a device for measuring the phase nonlinearity of a digital phased array receiving channel, and belongs to the technical field of input signal testing. The method comprises the following steps: generating a baseband linear frequency modulation signal a, performing correction based on a correction signal a, and generating a broadband radio frequency linear frequency modulation signal b and a delay linear frequency modulation signal d; inputting the wide signal b into a digital phased array receiving channel to obtain multi-path baseband I / Q data c; performing cross-correlation operation on the multi-path baseband I / Q data c and the signal d to obtain correlation peak data e; carrying out peak value searching and interpolation operation on the correlation peak data e to obtain delay f at a peak value; generating a synchronous linear frequency modulation signal g based on the delay f and the integer accompanying delay; and calculating the phase nonlinearity h of the digital phased array receiving channel based on the signal g and the multi-path baseband I / Q data c. The method is small in algorithm software resource overhead and high in measurement speed, and auxiliary narrow pulse generation equipment and ultra-high-speed data acquisition equipment are not needed.

Description

technical field [0001] The invention relates to the technical field of signal testing, in particular to a method and device for measuring the phase nonlinearity of a receiving channel of a digital phased array. Background technique [0002] Phase nonlinearity is one of the important performance indicators of digital phased array receiving channel. An ideal transmission system has no phase nonlinear distortion. However, due to the influence of factors such as filters, mixers, amplifiers, and impedance matching networks in the receiving chain, the phase and frequency in the frequency band do not have a strict linear relationship. In broadband systems The performance is particularly obvious. The phase nonlinear index directly determines the degree of distortion of the signal passing through the transmission system, which not only affects the pulse pressure sidelobe performance of the radar system or the intersymbol interference performance of the communication system, but also...

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Problems solved by technology

But this method has the following limitations: First, it is impossible to directly measure the phase nonlinearity of an analog-digital hybrid system like a digital phased array receiving channel (from antenna to ADC baseband data); second, it is difficult to directly measure the phase nonlinearity of a frequency conversion system. Linearity; finally, the test efficiency is low, and the phase nonlinearity of large digital phased arrays with tens of thousands of channels cannot be measured simultaneously

This measurement method has strict requirements on the width of the test pulse, especially when the application of large bandwidth needs to generate extremely narrow pulses, which requires high hardware requirements

At the same time, the effective sampling window of this measurement method is a narrow pulse width. In order to obtain enough data analysis samples, the system sampling interval needs to be much smaller than the narrow pulse width. In broadband applications, ultra-high-speed data acquisition equipment is required, which increases the hardware cost burden.

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