A Simple and Efficient Switched-Mode Approach to Hardened Power Amplification

A radiation-hardened power amplifier using switchedmode techniques to effect linear amplification is described. The amplifier--consisting of a modulator, saturating switches, and a demodulator--is capable of delivering more than 50 watts peak output at an efficiency exceeding 60 percent, before and after exposure to 3.5 × 1014 n/cm2 (l-MeV equiv.) and 2.0 × 106 rads(Si). The amplifier is immune to catastrophic effects of a pulsed ionizing-radiation environment of short duration through peak dose rates exceeding 1 × 1011 rads(Si)/s. The magnitude of the output response at this level is less than 9 percent of the maximum output voltage, and recovery from transient ionization takes place within one cycle of the amplifier's 3-db cutoff frequency.