Double-chirp frequency multiplication signal generating device based on dual parallel modulator and method thereof

Abstract

The present invention discloses a double-chirp frequency multiplication signal generating device based on a dual parallel electro-optic modulator, and a method thereof, and relates to the field of microwave photonics and radars. In the device, the dual parallel electro-optic modulator consists of a phase modulator, and two intensity modulators respectively integrated in the upper and lower arms ofthe phase modulator; a continuous optical laser, a polarization controller, a dual parallel electro-optic modulator, and a photodetector are sequentially connected through the optical fiber, and theoptical detector is connected with a bandpass filter through RF cables; electrical signals are input to the two electro-optic intensity modulators respectively; and a double-chirp output electric signal with a multiple frequency and bandwidth is obtained from the output end of the bandpass filter. According to the technical scheme of the present invention, a single-chirp signal with a carrier frequency of C, a single-chirp signal with a bandwidth B and a microwave signal with a carrier frequency of 4C are used to generate a double-chirp signal with a carrier frequency of 2C and a bandwidth of2B; and the device can be used to generate a double-chirp pulse radar signal with a large bandwidth, has the advantages of a simple structure and easy integration, and can be used to effectively improve the range resolution of the radar system.

Description

technical field [0001] The invention relates to the field of radar, in particular to a photonics method to realize the generation of double-chirped pulse radar signals with high carrier frequency and large bandwidth. Background technique [0002] As a signal with a time-bandwidth product greater than 1, the linear chirped waveform is widely used in radar systems because it can increase the range resolution through pulse compression. However, due to the existence of the knife-edge ambiguity function, when the measured target has a large velocity, the Doppler frequency shift generated by the moving target will cause the radar ranging error and form the range-Doppler coupling effect. The double-chirped waveform, including the upper-chirped waveform and the lower-chirped waveform with the same bandwidth in the same pulse time period, was proposed to be applied in the radar system, which can eliminate the distance-doppler generated by the single-chirped waveform when measuring hi...

AI Technical Summary

Problems solved by technology

[0006] The invention provides a method using photonics to generate double-chirped waveforms with doubled carrier frequency and bandwidth, which can effectively reduce the range-Doppler coupling effect of the system when applied to radar systems, and solve the double-chirped waveforms generated in existing solutions. The problem that the carrier frequency and bandwidth of the chirp signal are limited by the input signal and the problem that the upper and lower chirp amplitudes of the generated double chirp signal are inconsistent

Images