A RF voltage-controlled oscillator (VCO) employs an onchip, high-Q, three-dimensional (3-D) coil inductor and micromachined variable capacitor for frequency tuning. Unlike conventional spiral inductors, the 3-D inductor minimizes the substrate loss and achieves a record Q of 30 at 1 GHz. The micromachined variable capacitor achieves a 15% tuning range with a nominal 2pF capacitance and a Q valu...