Resistive D-Band Mixers with Monolithic Integrated Broadband IF Balun and LO Amplifier

Two frequency converters have been developed as building blocks for monolithic integrated receivers and transmitters in millimeter-wave (mmW) communication and radar systems. Key elements are the different resistive fundamental mixer cores. One of them uses a novel three-finger high-electron-mobility transistor (HEMT) layout that has been designed to overcome the drain-source asymmetry of conventional multi-finger devices. Essential peripheral circuits are integrated on-chip, including two-stage buffer amplifiers which ensure stable LO drive across broad input power and frequency ranges. Compact passive IF baluns with more than 150% relative bandwidth support the conversion of wideband signals. All performance metrics, thereunder conversion loss, intermodulation distortion, and spurious suppression, are evaluated over frequency. To the best of the authors' knowledge, the evaluation of HEMT-based resistive <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$D$</tex>-band frequency converters in such depth represents a novelty and is a crucial step towards the development of sophisticated frontends.