RF amplifier using VRF151G and BLF 574 power RF mosfets

Two identical setups, each bearing one RF Mosfet type (VRF151 and BLF574) have been used. The equipment installed in the radiation zone consist of a RF Power amplifier, an RF load, cooling fans and a radiation compensation reference device. The reference device is the same as used for the RF Power amplifier. The irradiated setups, installed in the equipment room, provide adequate RF driving for constant amplitude operation (100W) and frequency sweep from 0.5 MHz to 5 MHz. Compensation for the TID effects on the threshold voltage displacement is derived from the reference device response and applied to the RF Power Amplifier device. The study aimed at evaluating the compensation effectiveness and the degradation of the amplifier characteristics in terms of maximum power, gain and phase variations. During the session, the configuration of CHARM was copper target no shielding hereafter defined as “CuOOOO”.