Author(s)

Cher-Shiung Tsai, Kwang-Jow Gan, Ming-Shin Lin

Department of Electrical Engineering, National Chiayi University, Chinese Taipei.
Department of Electronic Engineering, Kun Shan University, Chinese Taipei.

We demonstrate the design of a novel voltage-controlled oscillator (VCO), which is based on a metal-oxide-semiconductor field-effect transistor (MOS) differential amplifier with active load. This VCO achieves low phase noise and wide tuning range. The phase noise is –120 dBc/Hz at 600 KHz offset from a 1.216 GHz carrier frequency. This value is comparable to that of a LC-based integrated oscillator. The operating frequency can be tuned from 117 MHz to 1.216 GHz with the supply voltage varying from 1.3 V to 3.3 V. Therefore, the tuning range is about 90.38% which is larger than most of the LC and ring oscillator. The VCO circuit, which is constructed using a standard 0.35 μm CMOS technology, occupies only 26.25 × 7.52 μm2 die area and dissipated 10.56 mW under a 3.3 V supply voltage.

Voltage-Controlled Oscillator (VCO); Differential Amplifier; Phase Noise; Tuning Range

C. Tsai, K. Gan and M. Lin, "Low Phase Noise and Wide Tuning Range VCO Using the MOS Differential Amplifier with Active Load," Circuits and Systems, Vol. 3 No. 4, 2012, pp. 307-310. doi: 10.4236/cs.2012.34043.