Title :
An Open-Loop Half-Quadrature Hybrid for Multiphase Signals Generation
Author :
Chen, Huan-Sheng ; Lu, Liang-Hung
Author_Institution :
Dept. of Electr. Eng., Nat. Taiwan Univ., Taipei, Taiwan
Abstract :
In this paper, a passive half-quadrature hybrid (HQH) is presented for multiphase signal generation at radio frequencies. Utilizing capacitance ratios as the primary design parameters, the proposed hybrid exhibits excellent magnitude and phase balance even in the presence of process and temperature variations. Therefore, it is well suited for integrated-circuit designs with on-chip capacitive elements. Using a standard 0.18-μm CMOS process, the HQH circuit is integrated with a 5.6-GHz quadrature voltage-controlled oscillator (QVCO) and four down-conversion mixers for demonstration. As the QVCO oscillation frequency sweeps from 5.4 to 5.8 GHz, the measurement results indicate a root-mean-square (rms) magnitude error less than 0.5 dB and an rms phase error ranging from 4° to 7° at the half-quadrature outputs without any feedback correction.
Keywords :
CMOS integrated circuits; integrated circuit design; mean square error methods; mixers (circuits); radiofrequency measurement; signal generators; voltage-controlled oscillators; HQH circuit; QVCO oscillation frequency; down conversion mixer; feedback correction; frequency 5.4 GHz to 5.8 GHz; integrated circuit design; multiphase signal generation; on-chip capacitive element; open loop half quadrature hybrid; passive half-quadrature hybrid; process variation; quadrature voltage controlled oscillator; radio frequency; rms phase error; root mean square magnitude error; standard CMOS process; temperature variation; Capacitance; Clocks; Gain; Harmonic analysis; Impedance; Monte Carlo methods; System-on-a-chip; Half-quadrature signal generation; multiphase clocks; phase interpolator;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
DOI :
10.1109/TMTT.2011.2175236
