A modified coupled method for multiphase oscillator is proposed and demonstrated in a standard 0.18-μm CMOS technology. A self-injection-coupled (SIC) technique is used to couple two current-reused differential voltage-controlled oscillators (VCOs). Compared with the conventional parallel-coupled quadrature VCO (QVCO), the proposed QVCO using the SIC technique presents low phase noise without increasing dc power consumption. The proposed SIC-QVCO at 16.28 GHz demonstrated a low phase noise of-125 dBc/Hz at 1-MHz offset frequency and a tuning range of 290 MHz. The dc supply voltage and current consumption are 1.8 V and 6 mA, respectively. The chip size of the proposed SIC-QVCO is 0.75 × 0.6 mm2.
|頁（從 - 到）||623-627|
|期刊||IEEE Transactions on Circuits and Systems II: Express Briefs|
|出版狀態||已出版 - 2012|