Optimisation of drift region width with reference to noise in Si DAR IMPATT diode

The noise behaviour of a Si DAR IMPATT diode is studied for different width of the v-region keeping the total diode width constant, using a realistic computer simulation method developed by us. Our results indicate that there exists an optimum width of the drift region of a DAR diode for which the mean square noise voltage of the diode would be the minimum. For a Si DAR diode designed for operation at 80 GHz the optimised width of the v-region is found to be 100 nm.