A W-Band Marchand Balun in 0.1 μm GaAs pHEMT Process

The increasing interest in fully differential W-band circuit designs poses the requirement for high-performing balun circuits. This paper proposes a Marchand balun implemented in WIN Semiconductor’s 0.1 µm GaAs pHEMT process. The circuit demonstrates excellent broadband performance across the frequency range from 82.5 GHz to 123 GHz with a measured insertion loss of 1.5 dB. The average measured magnitude and phase imbalances are less than 0.25 dB and 1.25
⁰
respectively. To the best of the authors’ knowledge, this is the best-reported W-band Marchand balun with minimum insertion loss and phase and magnitude imbalances.