Design of a varactor-based coupling QVCO using bulk-injection technique

Abstract

A quadrature voltage-controlled oscillator (QVCO) using bulk injection technique is presented in this paper. This QVCO is based on the coupling of two LC-VCOs without using any additional coupling devices. The proposed topology is compared with the conventional QVCO in terms of phase noise, quadrature phase error, tuning range, and power consumption. The QVCO achieves a simulated quadrature phase error of 0.65° and a measured phase noise of ?119.7 dBc/Hz at 1 MHz offset with a center frequency of 3.7 GHz. The proposed QVCO consumes 0.36 mW from a 0.45 V supply voltage. The QVCO is implemented in a standard 0.13 μm CMOS process with core area of 0.315 mm2.