New generation of S band T/R module

This paper describes a new S band T/R module which has been developed to equip the MASTER radar, an air defense radar. The particularity of this module is its very high power in a wide frequency band (more than 1.2 kW peak power in S band) with very long pulses (up to 200 μs) and high duty cycle (15%). The very good pulse to pulse stability figure is the result of a deep study which has been made taking into account the thermal phenomena and the power supply fluctuations. The main parameters for the reception path is a very low noise figure (2 dB typical including the duplexer and the limiter losses), the amplitude/phase control with a very high accuracy. The design of the module was made to ensure a very high reliability (it was designed to ensure a MTBF better than 33000 hours): the junction temperature of the component is very low in order to increase their MTBF. This very high MTBF is achieved by an appropriate cooling of each component with an efficient cooling plate