GaAs planar Gunn diodes for DC-biased operation

The difficulty in obtaining CW oscillations in GaAs planar Gunn diodes has been found to be due to distortion of the field distribution by a field-enhanced trapping effect. A tapered active region is proposed to compensate for the effect due to the trapping. By adopting the geometry, coherent CW Gunn oscillations have been obtained successfully with reasonable reproducibility.