A broadband highly linear BiCMOS mixer for direct conversion applications

A highly linear BiCMOS double balanced mixer for direct conversion applications is described and optimized. Based on the combination of active and resistive concepts, and modeled as a variable feedback amplifier, it achieves a high linearity and a good conversion gain. The performances achieved are; a conversion gain up to 12 dB, an output P_{-1 dB} of -5 dBm, and a high linearity, with an OIP3 of about +23 dBm and an OIP2 not less than +54 dBm, while requiring a local oscillator power no more than +4 dBm. As it covers a broadband RF spectrum, it can be used for receiving all communication networks located from 0.9 GHz until 2.2 GHz. When active, it drains 6 mA from 3.6 V.