Calibrating method for big modulation bandwidth linear FM signal frequency response

Abstract

A calibrating method for big modulation bandwidth linear FM signal frequency response relates to the technical field of testing, comprising the steps of: 1) dividing a radio frequency signal in a complete frequency range generated by a calibrating device into a plurality of frequency sections F0 to F1, F1 to F2,..., FM-2 to FM-1 and FM-1 to FM, for calibrating section by section, 2) confirming N+1 calibrating points on a single calibrating frequency section, 3) dynamically acquiring a log amplifying sensitivity R, 4) translating and searching the smallest carrier power, and 5) automatically calibrating frequency points FM one by one. The method of the invention automatically calibrates and compensates basing on the linear FM signal frequency response of an interior detection circuit and an agility damping circuit in the calibrating device and the frequency response calibration can be automatically performed without an additional testing and calibrating device for user to perform real time calibration on site. The detection circuit and the agility damping circuit are both located in a modulating channel, so not only the frequency response of linear FM signal generating module is calibrated but also the whole passage is calibrated.

Description

technical field [0001] The invention relates to the technical field of testing, in particular to a method for calibrating the frequency response of a linear frequency modulation signal with a large modulation bandwidth. Background technique [0002] Linear frequency modulation (LFM or Chirp) is the earliest and most mature pulse compression technology, which was proposed as early as the late 1940s. One of the outstanding advantages of this signal is that it can match The filter is not sensitive to the Doppler frequency shift of the echo signal, which greatly simplifies the requirements for the subsequent signal processing system, so it is widely used in the fields of radar, signal simulation and test instruments. [0003] Chirp signals are widely used in the field of radar and testing technology. FM frequency response is an important indicator of the amplitude-frequency characteristics of chirp signals, which describes the amplitude fluctuations in the effective frequency ba...

AI Technical Summary

Problems solved by technology

It can be seen that the accuracy of external measuring instruments and standard comparison parts, and the error of the algorithm will have a great impact on the calibration effect. At the same time, the complicated calibration process is not conducive to the efficient production of chirp modules.

In addition, due to the need for measuring instruments and standard comparison parts, this method cannot implement real-time calibration at the user's site

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