MULTIBAND (WiBro/WCDMA/CDMA 2000 1x) VOLTAGE-CONTROLLED OSCILLATOR FOR MOBILE COMMUNICATION

Abstract

In this article, a fully integrated multiband voltage-controlled oscillator (VCO)implemented in a 0.18-mu m CMOS process is presented. A complementary differential structure that consists of NMOS and PMOS transistors is used for low power consumption. To achieve good phase noise performance, no current source is used in the structure. MOS switches are employed for multiband selection. In addition, jour MOS varactors are added for band fine tuning; the first pair of MOS varactors is employed for channel selection, and the second pair of MOS varactors and MOS switches is employed for band selection. The total chip area of the VCO is 1.2 mm x 0.85 mm. The measured phase noise levels of the VCO are -98.8 dBc at 100 kHz, -116.4 dBc at 1MHz, -135 dBc at 10 MHz for CDMA 2000 1 X, WCDMA. and WiBro, respectively. The VCO draws 13 mA and consumes 23.4 mW with output buffers within the operating frequency of a 1.8 V supply. (C) 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 416-418. 2009: Published online in Wiley Inter-Science (www.interscience.wiley.com). DOI 10.1002/mop.24081