This paper presents a 60 GHz, 16% tuning range VCO, and a 40 GHz, 18 bits, 14% tuning range DCO incorporating variable inductor (VID) techniques. The variable inductor, consisting of a transformer and a variable resistor, is tunable by adjusting its resistor. By employing the proposed frequency tuning scheme, wide-tuning range as well as multi-band operation are achieved without sacrificing their operating frequencies. To verify the operation principles, the VCO and DCO are both fabricated in 90 nm CMOS technology. The tuning range of VCO is from 52.2 GHz to 61.3 GHz. The measured phase noise from a 61.3-GHz carrier is about - 118.75 dBc/Hz at 10-MHz offset, and the output power is -6.6 dBm. It dissipates 8.7 mW from a 0.7-V supply, and the chip size is 0.28×0.36mm2. On the other hand, the DCO is capable of covering frequency range from 37.6 GHz to 43.4 GHz. The measured phase noise from a 43 GHz carrier is about -109 dBc/Hz at 10-MHz offset, and the output power is -11 dBm. The DCO core dissipates 19 mW from a 1.2-V supply. Chip size is 0.5×0.15mm2.