A Study of Striped Inductor for K- and Ka-Band Voltage-Controlled Oscillators

A striped inductor and its utilization of a voltagecontrolled oscillator (VCO) are studied with the aim of suppressing phase noise degradation in Kand Ka-bands. The proposed striped inductor exhibits reduced series resistance in the high frequency region by increasing the cross-sectional peripheral length, as with the Litz wire, and the VCO of the striped inductor simultaneously exhibits a lower phase noise than that of the conventional inductor. Striped and conventional inductors and VCOs are designed and fabricated, and their use of Kand Ka-bands is measured. Results show that the Q factor and corner frequency of the striped inductor are approximately 1.3 and 1.6 times higher, respectively, than that of the conventional inductor. Moreover, the 1-MHz-offset phase noise of the striped inductor’s VCO in the Kand Ka-bands was approximately 3.5 dB lower than that of the conventional inductor. In this study, a 65-nm standard CMOS process was used. key words: skin effect, striped inductor, Q factor, corner frequency, voltage-controlled oscillator, phase noise