Optimum transit angles of millimeter-wave Si IMPATT diodes
Optimum transit angles for maximum output power in the millimeter-wave IMPATT diodes are calculated analytically by considering the carrier diffusion process through the space-charge region. It is found that the optimum transit angle decreases, as the space-charge layer width reduces. The theoretical results show satisfactory agreement with the previously published experimental results for Si p+-n-n+abrupt junction diodes.
The effect of series resistance on avalanche diode (IMPATT) oscillator efficiency
Theoretical results are derived for the transmission efficiency in an IMPATT diode oscillator. The transmission efficiency is a measure of the RF losses in the passive diode resistance and the circuit which couples the diode to the load.
Carrier Diffusion in Semiconductor Avalanches
The effect of carrier diffusion has been evaluated in a large‐signal analysis of semiconductor avalanches in the quasistatic approximation. It is shown that diffusion tends to smooth out the carrier distributions by upstream diffusion against the drift velocities, which causes a change in the carrier induced electric field. The dc solutions of the carrier and current distributions can be used in evaluating the effects of diffusion on the current response of the avalanche. The main effect is to increase the intrinsic response time with the ratio between the characteristic diffusion length D/v and the width of the avalanche region w as a critical parameter. In the effective avalanche width approximation a correction factor for the intrinsic response time due to diffusion is calculated. The results are also presented in curves with α/β and D/wv as parameters. The correction factor is found to increase linearly with D/vw for small values and saturate for large values. A criterion is given for the maximum mult...