RF system group delay parameter measuring method

Abstract

The invention discloses an RF system group delay parameter measuring method which comprises the steps as follows: the moving contact of a single-pole double-throw switch is combined with a first fixed terminal; a first pulse signal is sent to a first analog-digital converter through a pulse signal generator, and a second pulse signal is sent to a modulator through the pulse signal generator; a first carrier signal is sent to the modulator through a first RF source; the second pulse signal is modulated into the first carrier signal through the modulator; a signal with a new time delay is demodulated through a square law detector; a first synchronous sampling clock signal is sent to a power divider through a second RF source, and the first synchronous sampling clock signal from the second RF source is divided into two paths through the power divider. The measuring method utilizes the square law detector to demodulate a modulated signal, so as to avoid the introducing errors and improve the measuring accuracy which is better than 1 ns. The applicable frequency range of the measuring method is 100 MHz-50 GHz.

Description

technical field [0001] The invention relates to the technical field of measuring radio frequency system group time delay parameters, in particular to a method for measuring radio frequency system group time delay parameters. Background technique [0002] Group delay is a physical quantity used to describe the phase-frequency characteristics of a signal transmission system, and is one of the important performance indicators of a transmission system. Due to the limitation of the physical characteristics of the radio frequency system itself, there is inevitably phase dispersion in the radio frequency system, and the phase dispersion causes changes in group delay parameters at different frequency points, thus affecting signals transmitted in the radio frequency system. Therefore, it is of great significance to accurately measure the group delay parameters of the radio frequency system at different frequency points to determine the performance index of the entire radio frequency ...

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Problems solved by technology

Among them, the sinusoidal modulation phase detection method obtains the time delay between the modulation information and the original information through phase detection, so the sinusoidal modulation phase detection method is susceptible to the influence of multipath reflection in the radio frequency system to be tested, and its measurement accuracy is low; pulse modulation peak value comparison The method determines the delay by peak detection first, and then compares the peak value of the modulated pulse. Therefore, there is a contradiction between the measurement accuracy of the pulse modulation peak comparison method and the measurement aperture, and it is difficult to accurately reflect the curve fluctuation of the group delay parameter of the RF system to be measured. ; The structure of the measuring device used by the BPSK receiver method is complex, cannot be calibrated, and it is difficult to improve the measurement accuracy through post-processing

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