A Frequency Tripler Using a Subharmonic Mixer and Fundamental Cancellation

A new odd-order frequency multiplier topology is demonstrated in this work that uses a subharmonic mixer to realize a frequency tripler. A feedforward circuit is used for fundamental cancellation at the output and eliminates the need for filtering structures. For demonstrative purposes, and to validate the concept, a 1-3-GHz proof-of-concept frequency tripler circuit was fabricated. The tripler circuit achieved a measured output fundamental suppression of up to 30 dB below the third harmonic and a conversion gain of up to 3 dB. The circuit was implemented in CMOS 0.18-mum technology and the chip area was 0.8 mm² including bonding pads.