RF-to-Millimeter-Wave Receivers Employing Frequency-Translated Feedback

This article presents multi-band direct-conversion receivers (RXs) with frequency-translated negative feedback. The forward path includes a low-noise transconductance amplifier (LNTA) followed by four-phase passive mixers that drive baseband amplifiers. A feedback path employs tunable resistor banks attached to additional four-phase passive mixers, allowing tunable, frequency-selective input matching around a wide range of local oscillator (LO) frequencies. The passive mixers are driven by 25% duty-cycle, non-overlapping quadrature LO waveforms, and two different methods are presented for generating such waveforms. Two RX variants, differing in their LO generation schemes, are fabricated in 45-nm SOI CMOS. The first operates from 6 to 30 GHz, exhibiting greater than 25-dB gain and 4.1-10.5-dB noise figure (NF). A second operates from 10 to 50 GHz, achieving greater than 18-dB gain with 7.1-17-dB NF across the band. For either version, the instantaneous bandwidth is 960 MHz for the highest gain setting and 1375 MHz with reduced gain, measured at 10 GHz LO. The in-band third-order intercept point (IIP3) is - 5.4 dBm, the in-band IIP2 is + 16.5 dBm, and the out-of-band 1-dB blocker compression is greater than - 15 dBm. The RX core consumes 71 mW, while LO circuitry in each variant consumes 48-182 and 72-262 mW from 10 to 50 and 6 to 30 GHz, respectively.