A 71–86 GHz bidirectional image selection transceiver architecture

A bidirectional image selection transceiver is presented that operates over 71–76 GHz and 81–86 GHz with only 3 GHz of LO tuning range. A sliding-IF architecture with bidirectional VGAs allows operation in transmit and receive modes. The sliding IF and narrow LO tuning range allow wideband image rejection using a single stage polyphase filter. The circuit is implemented in a 90-nm SiGe BiCMOS process. Measurements indicate conversion gain of −2.5 dB to 3 dB with less than ±0.75 dB variation over 10 GHz in TX mode and −4dB to 0 dB with less than ±1 dB variation over 10 GHz bandwidth in RX mode. With 16- and 64-QAM, the EVM is below 5% and 4% at data rates of 6 Gb/s and 9 Gb/s. The RF and LO circuitry consumes at most 150 mW and 250 mW.