High-Order Subharmonic Millimeter-Wave Mixer Based on Few-Layer Graphene

A millimeter-wave subharmonic-mixer topology based on a few-layer graphene component has been designed, manufactured, and experimentally characterized. The circuit has been conceived to perform the up/downconversion of a signal in the WR-3 band, between 220-330 GHz, using a high-order harmonic component of the input signal in the WR-28 band, between 26.5-40 GHz, as a local oscillator. The manufactured prototype has been characterized in both upconversion and downconversion, for the subharmonic orders between 5-14, obtaining a peak conversion gain value over -65 dB. The theoretically predicted capability of graphene to produce high-order intermodulation products at millimeter-wave frequencies, with a slowly decaying amplitude pattern, has been experimentally verified.