Noise reduction in transferred electron oscillator modules

The paper reports on the FM noise performance of oscillators based on GaAs transferred electron devices characterized by carrier notches in the cathode region. The notches are incorporated into completed and encapsulated devices by ion-implantation technique. The low-conductivity region (carrier notch) thus formed is highly stable up to 400 C, thereby enabling the devices thus fabricated to be operated under normal continuous-wave conditions. The oscillator modules used are reduced-height post-mounted waveguide structures mechanically tunable over the frequency band 7-12 GHz. It is shown that useful improvements in the FM noise performance close to the carrier can be obtained.