A low supply voltage and wide-tuned CMOS Colpitts VCO

Abstract

This paper presents a g m -boosted differential Colpitts VCO with a switched capacitor tuning scheme which achieves low phase noise and a wide tuning range at a low supply voltage. In the proposed VCO, a voltage boosting circuit increases a turn-on resistance of the switching transistor for the capacitor array by generating higher gate bias voltage. As a result, the proposed VCO can achieve a wide frequency tuning range at a low supply voltage. The proposed VCO is implemented with 0.18-µm CMOS technology and oscillates from 3.60 to 4.14 GHz. Measurement results indicate a phase noise of !123.65 dBc/Hz at 1-MHz offset at 3.63 GHz, while dissipating 2.53 mA from the 0.7-V supply.

A low-power high-output-efficiency bipolar Colpitts VCO using base inductive feedback and Q-factor enhancement for analog signal acquisition

“…It is also seen that the simulation results are nearly consistent with the numerical calculation results via Eq. (14). As shown in Fig.…”

“…As a power-hungry component in RF transceiver, voltage-controlled oscillators (VCOs) often contribute a large power dissipation of these portable wireless systems. Colpitts VCOs are widely applied in wireless communication systems because of their simple structures and good phase noise performance [11][12][13][14]. Because the noise and linearity performances of bipolar devices are always better than MOS devices, bipolar Colpitts VCOs attract more attention in the analog signal direct-transmission, such as radio microphones, wireless instruments and so on.…”

An 8–12.5-GHz LC PLL with Dual VCO and Noise-Reduced LDO Regulator for Multilane Multiprotocol SerDes in 28-nm CMOS Technology

“…Although faster links beyond 60 Gbps are beginning to replace the 10-25-Gbps ports, 10-25 Gbps is still the mainstream data rate in the industry. Because of the increase in the data rate of the SerDes system, the PLL design has encountered more challenges, such as a high-frequency design and a wide frequency-tuning range with a low-jitter design [3][4][5][6][7]. Ring PLL and LC PLL are the two most widely used integrated on-chip PLLs.…”