Microwave properties of a proposed read-like device with variable current multiplication in the avalanche zone and an additional transverse field in the drift zone

A study of the high-frequency properties of a Read-like IMPATT device, which is arranged to have a variable current multiplication in the avalanche zone by means of controlled injection of minority carriers into the reverse biased junction, and also an additional transverse field in the intrinsic drift region, is presented. The additional field shifts the direction of space-charge waves emerging from the avalanche layer without altering the drift velocity which is already saturated. It is shown that the frequency of the maximum negative conductance, avalanche frequency, magnitude of the negative conductance, and susceptance of the device can be controlled over a wide range by varying the current multiplication in the avalanche zone. It is also shown that a fine variation of the negative conductance without altering the avalanche frequency or susceptance can be obtained by means of the additional transverse field.