A dual-tapped microstrip resonator VCO

A high loaded Q resonator and harmonic output topology are both potent technique to realize a low phase noise oscillator. This paper proposes a low phase noise Voltage Controlled Oscillator (VCO) with harmonic output, using a dual-tapped microstrip resonator of the high loaded Q factor. The paper also shows a load circuit configuration to suppress the output of the fundamental oscillation. The output frequency and the phase noise of the prototyped VCO are 15.652GHz to 15.7GHz, and less than -104dBc/Hz at 100kHz offset from the carrier, respectively. The fundamental and the second harmonic output are less than -37.6dBm, and -8dBm, respectively. The VCO fabricated on a resin substrate achieves the low phase noise on a par with other reported dielectric resonator oscillators (DROs), while manufacturable at lower cost than DROs.