Design of Linear Passive Mixer-First Receivers for mmWave Digital Beamforming Arrays

A 25-40GHz passive mixer-first receiver using a novel architecture for digital beamforming arrays is proposed. The architecture uses a novel technique for impedance matching using the on-resistance of the mixers in the receiver and matching networks. The small switch resistance of the mixers can be matched to the antenna using matching networks. Several matching networks are discussed, including a tunable matching network for wideband applications. The design achieves a noise figure that is lower than 8dB, a conversion gain of 18dB, and an IIP3 of around +4dBm across the frequency range of 25-40GHz. A prototype chip is fabricated in 28nm bulk CMOS process.