A 0.06 mm^2 11 mW Local Oscillator for the GSM Standard in 65 nm CMOS

A GSM-compliant local oscillator consuming a tiny die area of only 0.06 mm^2 and drawing 9 mA from a 1.2 V supply has been designed in a 65 nm CMOS process using thin-oxide devices only. The system is made of a 13 to 15 GHz LC VCO followed by a divide-by-four injection-locked frequency divider. The divider employs a ring oscillator-based topology leading to a two octave locking range with limited area and power consumption. The phase noise at the output of the divider is below -133 dBc/Hz at 3 MHz offset over the tuning range.