A packaged 1.1-GHz CMOS VCO with phase noise of -126 dBc/Hz at a600-kHz offset

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_DD=1.5 and 2.7 V, respectively. The VCO is implemented in a low-cost 0.8-μm 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