Design of a G-band frequency doubler based on a pair of parallelly mounted dual-diode chips

This paper presents the design and preliminary test results of a 166-188GHz frequency doubler using two flip-chip dual Schottky diode chips. The purpose of this work is to explore the feasibility of a simple and compact HMIC circuitry for frequency doubling with a higher power handling capability in this band. The designed doubler module consists of a pair of parallelly mounted Schottky dual-diode chips, two E-plane probes located in the input and output waveguide, a BPF for fundamental wave trasmission, two CMRC LPFs for DC biasing as well as impedance matching circuits at both driving and output port of the chip pair. The douber features four Schottky anodes closely located at a very compact region, being no need for additional power dividing and combining circuit. Preliminary measurement has been done on the fabricated doubler. It delivers an output power of 0.5±2.5dBm across the band of 166-188GHz with an input driving power of about 17dBm at W-band. The measured output power has a monotonously increasing tendency with respect to the input power, which demonstrates its potential of providing more output power at G-band if driving source with higher power level is applied.