A Low Phase-Noise, High Output Power, Differential VCO Using Series and Parallel Resonant Circuits

摘要

定電流源に直並列共振回路を用いた低位相雑音，高出力差動 VCO について述べる．低位相雑音を実rn現するために，従来の定電流源に代わって直並列共振回路を用いた．直並列共振回路は設計帯域内ではインダクタrnとなり，Hartley発振器のように動作する.また帯域外ではインピーダンスが低いHPFまたはLPFになり，不要なrn発振を防止する.定電流源に直並列共振回路を用いた差動 VCO を1GHz帯で設計，試作，評価を行い，-108 dBc／Hzrn＠100kHz at 990 MHz の位相雑音特性，＋12dBm の高出力特性が得られた．%A low phase-noise, high output power SiGe HBT differential VCO has been developed by using series and parallel resonant circuits. In order to achieve low phase-noise, high output power, and stable oscillation, series and parallel resonant circuits are used in place of the current source. The series and parallel resonant circuit operates as an inductor within the design band, LPF or HPF out of the design band. The LPF or HPF becomes short-circuited out of the design band, contributing to a stable oscillation. With the use of the resonant circuit, the VCO achieves a phase noise of-108 dBc/Hz @ 100 kHz at 990 MHz and an output power of greater than +12 dBm for a supply voltage of 2 V and a current consumption of 35 mA.