An 1.1-GHz packaged CMOS VCO with phase noise of -126 dBc/Hz at a 600-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 reference [1], these satisfy the GSM requirement. The extrapolated phase noise at a 3-MHz offset is -140 dBc/Hz. The power consumption is 6.8 and 12.7 mW at VDD=1.5 and 2.7V, 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, bond wires and 2 package leads to increase Q. This technique requires no extra board space beyond that needed for the additional package leads.