Method and device for generating chirped microwave pulse signal based on non-linear effect of electro-optical external modulation

Abstract

The invention discloses a chirp microwave pulse signal generation method and device based on an electro-optic external modulation nonlinear effect. Under a large signal modulation mode, single-wave-length-light carrier waves are subjected to phase modulation with a large modulation depth in an electro-optic modulator; relative phase shift or malposition are introduced into phase modulation signals through a dimmable delaying module, after nonlinear frequency chirp zone selecting is achieved through a time domain switch, the signals are input to an photoelectric converter for beat frequency, and microwave pulse signals with adjustable pulse speed, pulse and center carrier frequency are obtained. The method and device have the photonics advantages of being high in frequency, large in instant bandwidth and the like, and have the advantages of being high in signal parameter accuracy, easy to tune, relatively simple in structure, wide in application prospect and the like.

Description

technical field [0001] The invention relates to microwave photonics, electro-optic modulation technology, especially photon technology type microwave signal generation technology. Background technique [0002] In modern radar systems, chirped microwave pulse signals with large time-width-bandwidth products are often used to improve the ranging accuracy and distance resolution of radar. At present, commonly used chirped microwave pulse signals are generally generated based on electronic devices or devices. However, with the development of technology, the chirped microwave pulse signal generated by traditional electronic methods has been unable to meet people's actual application needs due to the limitation of its bandwidth and frequency band. Therefore, it has become a research hotspot to seek a generation scheme of chirped microwave pulse signals that can achieve higher carrier frequency and wider bandwidth. [0003] Photogenerated microwave pulse technology based on micro...

AI Technical Summary

Problems solved by technology

First of all, the wavelength-time domain mapping processing accuracy is not high, which will directly lead to inaccurate parameters of the generated signal (for example, it is difficult to control the accuracy or deviation of the center carrier frequency of the generated signal to reach the order of 100 MHz); secondly, Independent, precise, and fast tuning of multi-dimensional parameters of pulse signals is also a major challenge (most operations such as changing the shape of the filter passband, the free spectrum area of ​​​​frequency domain shaping, and the size of the dispersion value are completed by physical actions, and the response speed is relatively lagging)

Thirdly, most of the above solutions use short-pulse light sources, optical frequency combs, etc. These light sources are expensive, bulky, and complex to tune, and are not easy to miniaturize and flexibly

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