Research on transmission control technology of microwave signal with high density

Microwave signals transmitted through optical fibers have the advantages of large communication capacity, low transmission loss, high bandwidth, easy maintenance, and high security. The coherent light detection technology of microwave signals solves the problems of low direct detection sensitivity and limited power, and is therefore widely used in wireless communication systems, radar systems, satellite communication systems, and other fields. This article first provides a theoretical analysis of three modulation methods (AM, PM, FM) and coherent detection methods of homodyne and heterodyne. By observing spectral changes, coherent demodulation theories corresponding to three modulation methods were derived, and the results showed that amplitude modulation is the most suitable method for microwave signal transmission. The study analyzed the nonlinear characteristics generated by MZ modulators on LiNbO3 substrate during the modulation process, and pointed out that the greater the deviation between the modulation signal and the standard operating point, the worse the linear effect. The research results indicate that using microwave signal fiber optic transmission technology to replace traditional single microwave transmission and processing technology can effectively reduce energy consumption in long-distance signal transmission, improve the efficiency, security, and confidentiality of signal transmission.