Title :
Design of Wideband Low Phase Noise Class-C QVCO With Low Amplitude and Phase Errors
Author :
Haiwei Zhang ; Quan Xue
Author_Institution :
Dept. of Electron. Eng., City Univ. of Hong Kong, Hong Kong, China
Abstract :
This letter presents a wideband, low phase noise, quadrature voltage controlled oscillator (QVCO) implemented in 0.18 μm CMOS. In order to improve the phase noise while provide high efficient oscillation, the cooperation of a Class-C operation with a bulk-coupled structure are adopted into a PMOS-only VCO. With high fundamental current amplitude generated and the frequency offset of the QVCO alleviated, the phase noise is improved significantly. The measurement shows 2-8 dB phase noise improvement with a minimum value of -124 dBc/Hz at 1 MHz offset. Wide tuning range of 22.6% is realized by four-bit switched-capacitor-array ranging from 5.6 to 6.9 GHz. The quadrature accuracy of the proposed QVCO is evaluated by the measured results of an image-rejection mixer (IR-mixer), which exhibits a peak image rejection ratio (IRR) of 40 dBc, indicating low amplitude and phase errors simultaneously.
Keywords :
CMOS integrated circuits; integrated circuit design; microwave oscillators; phase noise; voltage-controlled oscillators; CMOS; Class-C operation; IR-mixer; PMOS-only VCO; bulk-coupled structure; four-bit switched-capacitor-array; frequency 5.6 GHz to 6.9 GHz; frequency offset; high efficient oscillation; image-rejection mixer; peak image rejection ratio; phase errors; quadrature voltage controlled oscillator; size 0.18 mum; wideband low phase noise class-C QVCO; CMOS technology; Phase noise; Voltage-controlled oscillators; Wideband; Wireless communication; CMOS Class-C QVCO; low amplitude and phase error; low phase noise; wideband;
Journal_Title :
Microwave and Wireless Components Letters, IEEE
DOI :
10.1109/LMWC.2015.2479838
