81–86 GHz VCO for Backhaul application with S-CPS based differential inductor in BiCMOS 55nm technology

This paper presents the design of a mm-wave VCO for Backhaul applications. This VCO operates between 81-86 GHz and was designed in the BiCMOS 55 nm technology. The innovation is linked to the use of a slow-wave coplanar strip (S-CPS) as a differential inductor. Thanks to high quality factor (≈ 33) of S-CPS, the phase noise and power consumption are improved. The proposed VCO is compared to the classical VCO (lumped inductor and varactor based). The S-CPS based VCO exhibits 3 dB less phase noise, and lower power consumption, with a phase noise of -111 dBc/Hz at 10 MHz offset and a power consumption of 6.84 mW. With 1.2 V supply, the tuning range reaches 7.9%, which is enough for the targeted application.