The small-signal inductive effect in a long P-I-N diode

The small-signal impedance of the forward-biased p-i-n diode has been calculated. It is found that, for a certain range of bias voltages, the impedance of the intrinsic region can be approximated by a parallel combination of resistance and inductance. If the intrinsic region is sufficiently long the junction impedance becomes negligible in comparision to the i-region impedance and a high Q inductor results at low frequencies. Values of Q up to 18 are calculated.