High-Voltage High-Efficiency Ultrawideband Pulse Synthesizer

A novel ultrawideband pulse synthesizer based on distributed amplifier topology is presented. The basic concept is to combine different delayed Gaussian pulses with both positive and negative polarities to form an UWB pulse. Compared to other ultrawideband pulse-formation methods, this method can have both high-efficiency and high-voltage output. The prototype circuit based on 0.25-mu m pHEMT transistors is fabricated, and the fabricated pulse synthesizer consumes only 1-mA current under 5-V power supply with high energy efficiency of 10.1% at 10-MHz pulse repetition frequency (PRF). Measurement results show that with 1.5-V amplitude and 240-ps Gaussian input pulse, the output pulse of the designed UWB pulse synthesizer is centered at 4 GHz with 4.5-V peak to peak amplitude (into 50-ohms load) and 1.0-ns duration at 50% of the peak pulse envelope.