9mW 6Gbps bi-directional 85–90GHz transceiver in 65nm CMOS

A Colpitts mm-wave VCO is used for modulating and de-modulating high data rates using two modes of operation, enabling multi-Gbps transceiver with small size and low power. As a VCO 4 GHz tuning range is achieved with a peak output power of +5 dBm at 87 GHz and a phase noise of -93 dBc/Hz at 1 MHz offset. Gate bias modulation achieves up to 6 Gbps ASK modulation with only 9 mW power consumption. In reverse operation as a detector without bias current, the circuit achieves a voltage responsivity of 4.5 kV/W, current responsivity of 5.4 A/W at 85 GHz and NEP of 0.95 pW/√Hz at 90 GHz. As a passive detector it achieves an open eye for 6 Gbps ASK data modulating an 85 GHz carrier. The design occupies only 0.18 mm² including pads.