A Broadband Balanced Distributed Frequency Doubler With a Sharing Collector Line

A broadband balanced distributed frequency doubler fabricated by 0.35 mum SiGe BiCMOS technology is developed to operate from 4 to 18 GHz output frequency. This balanced doubler consists of an active balun and a distributed doubler. A sharing collector line is used in the balanced distributed doubler to reduce the chip size. This circuit exhibits a measured conversion loss of less than 8 dB and a fundamental rejection of better than 23 dB for the output frequency between 4 and 18 GHz. The chip size is 1.1times0.7 mm
²
.