Improved efficiency microwave BARITT oscillators by delayed injection

A new microwave BARITT diode structure which utilizes an intentionally added retarding-field region is presented. By taking advantage of the carrier diffusion at low velocities in this region, the injected current is delayed relative to the ac voltage and improved efficiency diodes are obtained. Microwave CW oscillation at C band with efficiency of ∼4 percent has been realized. Although the efficiency is improved over previous BARITT diodes, it is believed that considerable further improvements are possible by further optimization.