Transmitters for coherent radars

The specifications of transmitters for coherent radars are derived from the required performances. Specific implementations using tubes or solid state devices are then discussed with emphasis on problems related to amplitude/phase coherency. It is shown that solid state transmitters have a better reliability and are redundant. However, they are limited in frequency, maximum power, and efficiency; they are also more complex to implement. Therefore, tubes will continue to be used in most coherent radar transmitters, despite the problems in power supply and modulator design associated with their phase characteristics.