Computer Studies on Pulsed Silicon MM-Wave IMPATT Diodes for various DDR Structures at High Current Density

Abstract

A review of the pulsed mode high power generation in silicon DDR IMPATT devices at high current density has been presented together with the current work of the authors in the same subject.

Computer studies have been presented on silicon pulsed IMPATT diodes with various double drift region (DDR) structures for operation at 94 GHz at a current density of 100 KA/cm². Three structures: (i) flat, (ii) SLHL, i.e., low-high-low structure with single bump on either side of the p-n junction and (iii) DLHL, i.e., low-high-low structures with double bumps on either side of the p-n junction have been investigated. The dc & small-signal results indicate that suitably designed silicon DDR IMPATT devices with double impurity bumps on either side of the junction exhibit much higher negative conductance and power output than other structures.

It is seen that appropriately designed DDR structures could be operated at a high current density of 100 KA/cm², with narrow avalanche zone to give sufficient W-band pulsed power, while several investigators have earlier suggested that the pulsed high power operation could be due to uniformly avalanching pin mode.