An Ultra-Low Power QVCO Using Current-Coupling and Bulk-Injection Techniques

Abstract

In this letter, a quadrature voltage-controlled oscillator (QVCO) using PMOS transistors to couple two VCO cores is presented. The power consumption is drastically reduced by using the bulk of the PMOS transistors to lower the transconductance of both differential pairs in the coupling network. The QVCO achieves a measured phase noise of ${-}116.02$ dBc/Hz at 1 MHz offset and a quadrature phase error of 0.48 $^{\circ}$ with a center frequency of 3.5 GHz. The proposed QVCO consumes 230 $\mu$ W from a 0.45 V supply voltage. The QVCO is implemented in a standard 0.13 $\mu$ m CMOS process with core area of 0.315 mm $^{2}$ .