Ground based radar modulator solid-state upgrade

A ground based radar modulator driving a twystron microwave amplifier has been designed, built and tested. It is a solid-state upgrade replacing a thyratron-based line-type modulator, including a shunt regulated resonant charge power supply and a pressurized SF6 insulated pulse transformer tank. The upgraded modulator is a high-current thyristor based line-type modulator with a command charge switching power supply and an oil-filled pulse transformer and socket assembly tank. The modulator produces a 117 kV, 80 A, 7.1 μs flat top pulse with 25 kW average beam power and is driven by a 400 Hz 208 V generator. The modulator is compact and the design is modular and interlocked for ease of maintenance and improved safety. This paper will provide details of modulator performance including operating data, output waveforms and environmental test results.