Coherent microwave photonic link for short-wave or ultra-short-wave broadband transmission

Abstract

The embodiment of the invention provides a coherent microwave photonic link for short-wave or ultra-short-wave broadband transmission. Due to the existence of a phase-locked loop, the phases of a first narrow linewidth laser and a second narrow linewidth laser synchronously change and are always kept in the same frequency and the same phase, and power jitter of radio frequency signals caused by phase jitter in a long-distance optical fiber is avoided; and the line widths of the two narrow-linewidth lasers are relatively narrow, so that the frequency difference between the optical signals output by the two narrow-linewidth lasers can be controlled within the frequency locking range of the phase-locked loop, and phase unlocking during short-wave or ultra-short-wave signal transmission is avoided. The problem of radio frequency signal power jitter caused by severe power attenuation and optical fiber jitter in a coherent microwave photonic link for short-wave or ultra-short-wave broadbandtransmission is solved. Based on a digital demodulation technology of a receiving end, the digital noise of a broadband demodulation signal is reduced, and the nonlinear distortion of a broadband cross-octave signal is effectively suppressed, so that a coherent microwave photonic link with a broadband large dynamic range is realized.

Description

technical field [0001] The invention relates to the field of communication technology, in particular to a coherent microwave photonic link oriented to short-wave or ultra-short-wave broadband transmission. Background technique [0002] Microwave photonics is a subject that uses optical methods to realize microwave signal processing. As the core of optical processing, microwave photonic link can realize processing functions such as conversion between microwave and light wave and transmission. Microwave photonic links have extremely wide application value in many fields such as radar positioning, wireless communication, electronic countermeasures, satellite communication, and television broadcasting. [0003] In the microwave photonic link, the radio frequency signal is modulated to the optical carrier, and then demodulated after being propagated through the optical fiber to restore the original radio frequency signal. The coherent microwave photonic link for short-wave or u...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the embodiments of the present invention is to provide a coherent microwave photonic link for short-wave or ultra-short-wave broadband transmission, which is used to solve the problem that the power of the received signal in the microwave photonic link structure with a large dynamic range in the prior art is greatly affected by fiber jitter , the power attenuation is also relatively serious, so it is difficult to realize short-wave or ultra-short-wave long-distance transmission

Images