Multi-band linear frequency modulation signal generation method capable of flexibly selecting frequency

Abstract

The invention discloses a multi-band linear frequency modulation signal generation method capable of flexibly selecting frequencies, and relates to the technical field of microwaves and the technical field of optical communication. The method is shown in a figure 1 in the specification, and comprises a laser device LD, a dual-polarization binary phase shift keying modulator DP-BPSK, an arbitrary waveform generator AWG, an erbium-doped fiber amplifier EDFA, a polarization controller PC, a polarizer POL and a photoelectric detector PD. Phase modulation is carried out on a local oscillator signal through the DD-MZM1 of the DP-BPSK upper arm, and carrier suppression double-sideband modulation is carried out on an IF-LFM signal through the DD-MZM2 of the DP-BPSK lower arm; the PC is adjusted, the phase difference between the two polarization states is controlled, and then a multiband linear frequency modulation signal can be obtained after POL and photoelectric detection. According to the invention, the electronic bottleneck of the electric field technology is overcome, and the characteristic of flexible frequency tuning is added; multi-band signals are generated at the same time, so that the system has potential application value in a multi-band radar and a distributed radar system.

Description

technical field [0001] The invention relates to the technical field of optical communication and microwave technology, and mainly relates to the generation of chirp signals by using photonics technology. Background technique [0002] The increasingly complex detection environment puts forward higher requirements for radar detection. When the radar system detects targets, the detection distance and distance resolution are indicators that need to be considered at the same time. In order to increase the detection distance, it is necessary to increase the average transmission power and the pulse of the detection signal. The width needs to be relatively large. In order to improve the distance resolution, the detection signal needs to have a large bandwidth, which is contradictory to the general signal, so the pulse compression signal came into being. Chirp signal is one of the microwave waveforms widely used for pulse compression in modern radar systems. It has received more and ...

AI Technical Summary

Problems solved by technology

In the first solution, although the system is flexible and scalable, the coupling between free space and optical fiber will increase the loss and complexity of the system, and the system usually faces the problems of large volume and large loss

In the second scheme, there is no need for spatial light processing, and the system will be more stable; using the flexible modulation mode and variable system structure of the electro-optic modulator, the chirp signal can be obtained simply and effectively, and the time-width bandwidth of the generated signal can be greatly improved. However, most of the solutions have a single function and can only generate chirp signals at a single frequency, which is difficult to apply to multi-band radar systems

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