Millimeter wave digital pulse modulation signal phase noise measuring device and method

Abstract

The invention discloses a millimeter wave digital pulse modulation signal phase noise measuring device comprising a power divider, two paths of digital signal processing devices, four pulse digital phase demodulation units and a digital cross-correlation processing unit. According to the millimeter wave digital pulse modulation signal phase noise measuring device, microwave and millimeter wave pulse modulation signals are received and then outputted through power division of the power divider. Fundamental wave mixing, intermediate frequency amplification and amplitude and phase adjustment areperformed on the microwave and millimeter wave pulse modulation signals through two paths of digital signal processing devices, and four paths of output signals are outputted to the four pulse digitalphase demodulation units, wherein every two pulse digital phase demodulation units form a detection channel, and cross-correlation processing is performed on the digital noise signals outputted by the two detection channels through the digital cross-correlation processing unit for suppressing the uncorrelated noise so as to optimize the bottom noise.

Description

technical field [0001] The invention relates to the field of millimeter waves, in particular to a device and method for measuring the phase noise of a millimeter wave digitized pulse modulation signal. Background technique [0002] The current phase noise measurement devices on the market mainly include imported HP3047A, HP3048A, E5500 series and PN9000, etc. The components of these devices mainly include phase detectors, phase-locked loops, low-noise amplifiers, analog repetition frequency (PRF) filters, Data acquisition and computers. For pulse modulation signals in the microwave and millimeter wave frequency range, these systems still use the traditional phase detector method. The phase detector method needs to establish a quadrature phase-locked loop during measurement and requires precise system calibration. However, in the phase noise calibration process for pulse-modulated signals, the disadvantages of this method are obvious. First of all, the pulse modulation sign...

AI Technical Summary

Problems solved by technology

For pulse modulation signals in the microwave and millimeter wave frequency range, these systems still use the traditional phase detector method. The phase detector method needs to establish a quadrature phase-locked loop during measurement and requires precise system calibration. However, in the phase noise calibration process for pulse modulated signals, the disadvantage of this method is obvious

First of all, the pulse modulation signal is obviously different from the continuous wave signal, and its carrier power decreases according to 20LOG (duty cycle). Measuring system cannot be locked

Secondly, the spectrum of the pulse modulated signal is expanded according to the envelope of the SINC function, and there is serious aliasing in the carrier noise sidebands. The effective analysis frequency range is PRF / 2 (PRF is the pulse repetition frequency), and the analog PRF filter is used to remove aliasing , an effective means to extract effective noise sidebands, but the bandwidth of the analog PRF filter is not adjustable, and the pulse repetition frequency is rich and varied, so the analog PRF filter cannot meet the calibration requirements of changing repetition frequency

In addition, the decrease of the carrier power directly results in the deterioration of the bottom noise of the phase noise measurement system. The deterioration of the bottom noise is carried out according to 20LOG (duty cycle), especially under narrow pulse modulation, the deterioration of the bottom noise is serious. Make the system unable to calibrate the phase noise index of the low noise microwave millimeter wave pulse modulation signal

[0003] At present, the problems of phase noise calibration of pulse modulation signals in the microwave and millimeter wave frequency range in China are: 1. Unable to lock during system calibration; 2. The bandwidth of the analog repetition frequency filter cannot be adjusted; 3. The bottom noise is seriously deteriorated; 4. Uncertainty in system calibration is large

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