Injection Pulling Mitigation in CMOS Voltage-Controlled Oscillator Using A Novel Honeycomb-Shaped Planar Inductor

This brief presents the injection pulling mitigation of a voltage-controlled oscillator (VCO) using a novel honeycomb-shaped planar inductor. Due to the twisted routes of the sub-coils in the proposed inductor, the interference caused by a nearby electromagnetic noise source can be compensated and reduced. By using a 0.18- {\mu }\text{m} standard CMOS process, the proposed inductor and a conventional single-turn spiral inductor in a similar size are integrated into two respective VCO testchips. The injection pulling behaviors of these two oscillators are studied and compared. The experimental results show that the VCO integrated with the proposed honeycomb-shaped planar inductor can significantly mitigate the injection pulling phenomenon as compared with the VCO integrated with a conventional single-turn inductor in a similar size. In this brief, the enhancement of mitigation over 15 dB can be achieved.