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A packaged 1.1-GHz CMOS voltage-controlled oscillator (VCO) with measured phase noise of -92, -112, and -126 dBc/Hz at 10-, 100-, and 600-kHz offsets is demonstrated. According to J. Craninekx et al. (1997), these satisfy the GSM requirements. The extrapolated phase noise at a 3 MHz offset is -140 dBc/Hz. The power consumption is 6.8 and 12.7 mW at V/sub DD/=1.5 and 2.7 V, respectively. The VCO is implemented in a low-cost 0.8-/spl mu/m foundry CMOS process, which uses p+ substrates with a p-epitaxial layer. Buried channel PMOS transistors are exclusively used for lower 1/f noise. The inductors for the LC tanks are implemented using a series combination of an on-chip spiral inductor, four bond wires, and two package leads to increase Q. This technique requires no extra board space beyond that needed for the additional package leads.
Date of Publication: Jan. 2000