Shoichi Hara

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SUMMARY The multiple-divide technique, using the multi-ratio frequency divider, has a possibility to improve FoM of VCO. This paper proposes a design optimization of LC-VCO using the multiple-divide technique. In the simulated results using 90-nm CMOS model parameters, the optimum frequency range, achieving better than −187.0 dBc/Hz of FoM, can be extended(More)
— This paper proposes a multiple-divide technique using by-2, by-3, and by-4 frequency dividers to realize a lower phase-noise LC-VCO, and explores the design space of low-phase-noise VCO using the multiple-divide technique. In the simulated results using 90-nm CMOS model parameters, the optimum frequency range, achieving better than −191 dBc/Hz of FoM, can(More)
SUMMARY In this paper we present a study on the design optimization of voltage-controlled oscillators. The phase noise of LC-type oscillators is basically limited by the quality factor of inductors. It has been experimentally shown that higher-Q inductors can be achieved at higher frequencies while the oscillation frequency is limited by parasitic(More)
SUMMARY This paper proposes a novel wideband voltage-controlled oscillator (VCO) for multi-band transceivers. The proposed oscillator has a core VCO and a tuning-range extension circuit, which consists of an injection-locked frequency divider (ILFD) and flip flop dividers. The two-stage differential ILFD generates quadrature outputs and realizes two, three,(More)
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