High-Linearity Double-Balanced Up-Conversion Mixer with an Active Balun Based on InGaP/GaAs HBT Technique

This paper presents a high-linearity double-balanced up-conversion mixer (DBUCM) based on InGaP/GaAs heterojunction bipolar transistor. The proposed DBUCM is combined with the Gilbert cell of an active push-pull type balun and designed for an interference cancellation system (ICS). Linearization techniques are applied to improve the linearity by introducing both emitter degeneration resistors (EDRs) and current injection resistors (CIRs). A DBUCM with EDRs and CIRs, which exhibited an overall chip size of 850 μm ×850 μm, was fabricated and implemented on a test board. The measured results indicated a conversion gain of -1.6 dB, a third-order intermodulation distortion of 54.2 dBc, a third-order output intercept point of -1.4 dBm, a third-order input intercept point of 0.2 dBm, and a 1-dB compression point of-11.0 dBm.