A Study on the Effect of Electron and Hole Saturation Currents on the Negative Resistance Profiles, Negative Conductance and the Frequency of Operation of Millimeter Wave (W-Band) Double-Drift Silicon IMPATT Diodes

Abstract

Computer studies have been carried out on the effect of electron and hole reverse saturation current on the high frequency (i) negative resistance and reactance profiles, (ii) admittance characteristics, and (iii) device quality factor of a silicon double-drift region (DDR) IMPATT operating in the mm-wave range (W-band). The results indicate that the negative resistance peaks in the electron and hole drift layers decrease with increasing reverse saturation current. The total diode negative resistance also decreases appreciably with the increase of either electron or hole reverse saturation current, ie, with decrease in electron or hole current multiplication factors (M & M_p).

It has further been observed that in the lower frequency range of the W-band, the device negative conductance decreases with the increase of reverse saturation current, while in the frequency range from 160–210 GHz, the device negative conductance increases with the enhancement of reverse saturation current.

An upward frequency shift by 10 GHz in the optimum frequency may be achieved by increasing the reverse saturation current for M_n = 25. The device quality factor also gradually increases with the enhancement of reverse saturation current.

Indexing terms:

• Electron and hole saturation currents
• Double-drift silicon IMPATT diodes