A Triple Tuned Ultra-Wideband VCO in X-K Band

We have already proposed a triple tuned voltage controlled oscillator (VCO) for achieving an ultra-wideband characteristic. The fabricated VCO in C-Ku band has achieved the oscillation bandwidth of 5.6 GHz-16.8 GHz. In this paper, for achieving the wide oscillation bandwidth in the higher frequency band, we proposes a VCO that consists of a MMIC working as an active circuit and external hyper-abrupt junction varacter diodes connect to the MMIC with Au wires. The fabricated VCO in X-K band achieves the oscillation bandwidth of 9.9 GHz-21.9 GHz and the phase noise of -109.4 dBc/Hz +/-2.4 dB at 1 MHz offset from the carrier. In addition, it is shown that the fabricated VCO achieves the widest oscillation bandwidth and the lowest phase noise in X-K band compared with other reported wideband VCOs.