A new type of silicon TRAPATT diode has been fabricated and tested. The diode has been designed to operate as a continuous-wave TRAPATT diode in the 4- to 6-GHz range. The diode structure is novel in that it employs an asymmetric double-sided design in which one side is optimized for TRAPATT operation and the other side is optimized for the generation of the 50-GHz IMPATT oscillations required for starting the TRAPATT oscillator. The diode was fabricated using ion-implantation techniques.