Noise in gallium arsenide avalanche Read diodes

The noise and signal properties of Read-type avalanche diodes under large-signal levels are examined. In contrast to most other previous theories, we include the saturation current in the equations rigorously from the beginning. We find that the noise performance is a strong function of the saturation current such that high saturation currents lead to lower noise performance. We compare the findings of our model with measurements on two very different Read-type avalanche diodes with a low-high-low profile. In agreement with theory, the lower noise diode has a higher saturation current. We also find experimentally that the noise measure of the diodes used as oscillators decreases with increasing power output. This feature is explained by the rising reverse saturation current with temperature which in some diodes more than compensates the normally increasing noise measure with power output.