A CMOS Quadrature Sub-Harmonic Up-Mixer with I/Q Calibration

• Main Authors: Hao-Yun Tang, 湯皓雲
• Other Authors: Jenn-Chyou Bor
• Format: Others
• Language: en_US
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/54005639093552316934

碩士 === 國立清華大學 === 電機工程學系 === 96 === n this thesis, quadrature up-mixer circuits with sub-harmonic pumping technique and I/Q imbalance calibration loop are implemented in 0.18-μm mixed-mode CMOS technology for 3.5-GHz direct-conversion WiMAX transmitter applications. The mixer operates in quadrature double-balanced mode and require octet-phase (0°, 45°, 90°, 135°, 180°, 225°, 270°,and 315°) local oscillator (LO) signals which come from two polyphase filter circuits. For I/Q impairment cancellation, a calibration loop is integrated in the feedback path of the up-mixer circuits. The amplitude and phase compensation circuits of calibration loop are powerless and area efficiency resistor networks. Both can replace the original resistors in the up-mixer circuits and have no influence the up-mixer performance. By using sub-harmonic and I/Q calibration technique, the LO leakage at the measured buffer output can be suppressed more than 51 dBc below the fundamental tone with 0 dBm input power. For the sideband suppression, it is higher than 41 dBc from 3.0 GHz to 3.7 GHz. The quadrature up-mixer circuit consumes 10.4 mA from 1.8 V supply and shows -4 dB conversion loss, 13.8 dBm OIP3 (17 dBm IIP3) and 3.9 dBm P1dB, respectively. The total chip area including the up-mixer circuits, testing preamp, testing output buffer and calibration loop is 1.3 μm x 1.3 μm.