1,25 kW S band pulsed Transmit/Receive module for microwave tube amplifier replacement

This paper presents the design and development of a high power S band (2.9–3.3 GHz) Transmit/Receive (T/R) module prototype. The motivation behind this development is to increase reliability and maintainability of modern radar systems by replacing microwave tube amplifiers with solid state counterpart. 1.25kW peak output power with a pulse width of 40 usec at a duty of %10 is achieved by combining 8 pallet amplifiers with a low loss, equal phase rf power combiner. A phase compensation circuit is also adopted to eliminate phase imbalances in the combining architecture. GaN HEMT is chosen as the semiconductor device in each pallet amplifier. The designed and developed GaN pallet amplifier delivers 54 dBm peak power with 8 dB nonlinear power gain.