Improvement of TRAPATT performance with optically generated carriers

It is demonstrated that a number of the difficulties which have thus far limited the application of the TRAPATT oscillator may be overcome by optically generating carriers within the device´s active region. Illumination with a short light pulse at the beginning of the bias pulse extends the ranges of (i) bias, (ii) circuit tuning, and (iii) temperature over which the duration of leading edge jitter is short. Illumination during the application of the bias pulse significantly shifts the oscillation frequency. It is shown that this effect may be used to eliminate undesirable intra-pulse frequency drift with shaped light pulses. Also, frequency switching in time-frames approaching one RF period are accomplished, which opens up new applications for the TRAPATT oscillator.