A High-Fractional-Bandwidth, Millimeter-Wave Bidirectional Image-Selection Architecture With Narrowband LO Tuning Requirements

An image-selection, two-element transceiver is presented that operates over a large fractional bandwidth (FBW) covering both 71-76 and 81-86 GHz while requiring only 3 GHz of local oscillator (LO) tuning range at the RF mixer. A bidirectional sliding-intermediate frequency (IF) Weaver architecture allows operation in either transmit (TX) or receive (RX) modes. The sliding IF and narrow LO tuning range allow wideband image rejection using only a single-stage polyphase filter. The circuit is implemented in a 90-nm SiGe BiCMOS process and the RF and LO circuitry consume at most 150 and 250 mW, respectively. Measurements show less than ±0.75-dB gain variation over 10 GHz in the TX mode and less than ±1-dB variation over 10-GHz bandwidth in the RX mode. With 16- and 64-quadrature-amplitude modulation (QAM), the error vector magnitude is below −22 and −28.5 dB at the data rates of 12 and 9 Gb/s, respectively.