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概述 MMDS发射设备用于电视信号的地面无线传输,其组成与VHF/UHF电视发射机很相似,其基本区别和特点在于: 1、上变频之后工作于2.5至2.7GHz频殴。 2、多频道邻频工作,发射机输出需经频道合成器再送往天馈,MMDS发射机在结构上不包括V/A双工器;其带外无用发射需满足邻频工作的技术要求,优于-60dB,即需与CATV前端同样要求。
Overview The MMDS transmitter device is used for terrestrial wireless transmission of television signals. Its composition is very similar to that of VHF / UHF television transmitters. The basic differences and characteristics are as follows: 1. After upconversion, work at 2.5 to 2.7 GHz. 2, multi-channel adjacent-frequency work, the transmitter output to be fed to the antenna by the channel synthesizer, MMDS transmitter structure does not include V / A duplexer; out of band unwanted emissions to meet the technical requirements for adjacent frequency work , Better than -60dB, which requires the same requirements with CATV front-end.