This paper addresses a half distributed solid state array radar system, which uses 54 L Band power amplifier modules ( 2 0 kW output power)The total space combination power of this system can reach up to 100kw for 150 p s pulse widths at 8% average duty cycle with a 14 5% instantaneous bandwidth Switching power supply and liquid cooling have been employed to achieve good performance and stable reliability Such a system has already been utilized in a three dimensional high performance radar