5.18–7.42 GHz LC-VCO in subthreshold regime with low power low phase noise and immunity to PVT variations in 130 nm CMOS technology

Abstract

In this paper, we propose an LC-VCO using automatic amplitude control and filtering technique to eliminate frequency noise around 2 $$\omega _0$$ . The LC-VCO is designed with TSMC 130 nm CMOS RF technology, and biased in subthreshold regime in order to get more negative transconductance to overcome the losses in the LC-Tank and achieve less power consumption. The designed VCO operates at 5.17 GHz and can be tuned from 5.17 to 7.398 GHz, which is corresponding to 35.5% tuning range. The VCO consumes through it 495–440.5 $$\upmu$$ W from 400 mV dc supply. This VCO achieves a phase noise of $$-\,122.3$$ and $$-\,111.7$$ dBc/Hz at 1 MHz offset from 5.17 and 7.39 GHz carrier, respectively. The calculated Figure-of-merits (FoM) at 1 MHz offset from 5.17 and 7.39 GHz is $$-\,199.7$$ and $$-\,192.4$$ dBc/Hz, respectively. And it is under $$-\,190.5$$ dBc/Hz through all the tuning range. The FoM $$_T$$ at 1 MHz offset from 5.17 GHz carrier is $$-\,210.6$$ dBc/Hz. The proposed design was simulated for three different temperatures ( $$-\,55$$ , 27, $$125\,^{\circ }\hbox {C}$$ ), and three supply voltages (0.45, 0.4, 0.35 V), it was concluded that the designed LC-VCO presents high immunity to PVT variations, and can be used for multi-standard wireless LAN communication protocols 802.11a/b/g.