Compact sub-harmonic mixer for Q-band satellite communications

The design and performance of an extremely compact Q-band sub-harmonic mixer for EHF satellite communication is presented. Proposed architecture, integrating an LO buffering section, allows for the frequency conversion between Q and X bands by means of a 19.5 GHz pump signal. Double balanced mixer topology and multi-conductor RF balun respectively guarantee high port isolation and low conversion loss. Realized circuit results in a really compact implementation (2.4×2.4mm
²
) and operates in the 43.5–50 GHz band featuring about 12dB conversion loss.