High frequency Gunn oscillators

In the past several years there has been a renewed interest in millimeter wave sources due to the advent of microwave solid state devices. IMPATT, both single and double drift, and Gunn effect, LSA as well as fundamental mode devices, have demonstrated capabilities for power generation at millimeter wavelengths. Until recently, however, the so-called "fundamental mode\´ Gunn effect oscillator has not been able to compete with the power levels exhibited by these other devices.