Two wide-tuning-range mm-wave VCOs with SCTL and SCCPW in 45 nm SOI CMOS for 5G applications

A switched coupled transmission line (SCTL) method with high Q and flexible structure is proposed for mm-wave VCO to improve tuning range (TR), meanwhile maintaining low phase noise, low power dissipation and zero additional area. This TR extension method is also proved effective in a switched coupled coplanar waveguide (SCCPW) VCO. Fabricated in 45 nm SOI CMOS, the SCTL-VCO achieves 38.74% TR from 39.46 to 58.42 GHz, increased by 29.2% compared to the reference TL-VCO. The SCCPW-VCO achieves 38.83% TR from 38.69 to 57.33 GHz, increased by 31.9% compared to the reference CPW-VCO. The measured phase noise of SCTL-VCO and SCCPW-VCO over the entire frequency tuning range is from - 106 to - 116.8 and - 106.1 to - 116 dBc/Hz at 10 MHz offset, while the corresponding FOM_T is from - 181.7 to - 192.5 and - 181.6 to - 191.5 dBc/Hz, respectively. Each VCO dissipates 8.6–10.8 mW from 0.7 V power supply.