A 300 GHz balanced doubler based on planar Schottky diodes

Abstract

The structure and dimension of Schottky diode were designed. The loss at high frequency was reduced using a quasi-whisker contacted anode structure by a metal finger akin to an air bridge. The nonlinear model of Schottky anode and three dimensional electromagnetic(EM) model were established respectively according to the measured data and structure of Schottky diode. The diodes were placed in waveguide using balanced circuit design. The EM mode orthogonality ensured very good input and output signal isolation, which simplified the circuit structure and reduced the circuit loss. A 300 GHz doubler was designed and fabricated successfully. The efficiency is higher than 5% at 312～319 GHz with a peak efficiency of 10.1% at 316 GHz. The output power is higher than 4 mW at 307～318 GHz with a peak output power of 8.7 mW at 316 GHz. The diodes are replaced by one with higher doping concentration. The peak efficiency is 13.7% and the peak output power is 11.8 mW which reaches the similar level of reported doublers. The results proved the ability of Schottky diode working at high frequency.

Keywords

• doubler
• schottky diodes
• anti-series
• balanced
• terahertz