Pulse radar automatic frequency tuning peak point searching method

Abstract

The invention provides an FPGA based automatic frequency tuning fast peak point searching method. The process is that: a radio frequency signal received by a radar antenna is mixed with a local oscillator LO to obtain an intermediate frequency signal after being preprocessed by a front end; the intermediate frequency signal is divided into channels via the coupler, wherein one channel signal enters a signal processing end, and the other channel signal passes through a matching filter, and then enters an FPGA to perform the tuning algorithm processing via an ADC acquisition circuit; the FPGA performs peak comparison according to the acquired tuning values, and simultaneously controls a DAC waveform generator to output a voltage signal in a scanning manner; and the voltage signal passes through a driving device to control a VSO to output a local oscillation frequency LO corresponding to the voltage. The invention has the advantages that the peak value search is performed by using the quartile technology, the speed is fast, and the scanning time is shortened to 2*(N+1) / 2N of the original scanning time; based on the FPGA platform, it is easier to implement the quarter and the binary division, and only the high bit is needed. Resources can be greatly saved, the efficiency is improved, and the number of scans is reduced; and the method is more suitable for high-speed pulse radar occasions.

Description

technical field [0001] The invention relates to an automatic frequency tuning peak point search method for pulse radar. Background technique [0002] Pulse radar is the mainstream of modern radar, and high-power radar generally adopts pulse system. Magnetron is a high-power microwave component widely used in pulsed radar, which has the characteristics of high efficiency, small size, light weight and low cost. Due to the limitation of the manufacturing process, the transmission signal is extremely unstable, the oscillation frequency of different batches varies greatly, and the working frequency of the same batch is also different after starting up and warming up, and the frequency drifts with the change of temperature or load. When the magnetron is in the detuned state, the oscillation frequency will deviate. At this time, the intermediate frequency signal will easily fall into the stop band of the filter, and the echo amplitude will be greatly weakened. Due to the low reli...

AI Technical Summary

Problems solved by technology

[0003] The existing technical schemes use the full scan method to tune the frequency, so that the number of scan points required to obtain the peak value is large, the scan period is long, and the efficiency is low. In pulse radar, if the tuning scan period is too long, some high-speed targets may be lost or target discontinuity

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