Wide locking range divide-by-3 injection-locked frequency divider using differential-injection linear mixers and dual frequency tuning

A wide locking-range Ka-band CMOS divide-by-3 injection-locked frequency divider (ILFD3) using differential-injection linear mixers and dual frequency-tuning is demonstrated in a standard 0.18 μm CMOS technology. Divide-by-3 and low-voltage operation were achieved by the differential-injection linear mixers, which constitute two source-connected series NMOSFETs in parallel with the LC tank. In addition, two pairs of varactors were adopted to enhance the ratio of variable capacitance to the overall capacitance of the LC tank. This in turn results in an increase of the locking range (LR). Furthermore, a bypass capacitor was added to the drain terminal of the head current source to eliminate its noise contribution. The ILFD3 consumed 5.28 mW from a 1.5 V power supply. Measurement result shows the proposed ILFD3 achieved a state-of-the-art 19.84% (31.29–38.18 GHz) locking range and an excellent output phase-noise of −130.1 dBc/Hz at 1 MHz offset. The chip area was only 0.87 × 0.72 mm² excluding the test pads. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2622–2626, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26307