National Taiwan University Dept Elect EngnHsieh, Hsieh-HungHsieh-HungHsiehLu, Liang-HungLiang-HungLu2006-11-142018-07-062006-11-142018-07-062006-10http://ntur.lib.ntu.edu.tw//handle/246246/200611150121768A novel circuit topology for low-phase-noise voltage controlled oscillators (VCOs) is presented in this letter. By employing a PMOS cross-coupled pair with a capacitive feedback, superior circuit performance can be achieved especially at higher frequencies. Based on the proposed architecture, a prototype VCO implemented in a 0.18- m CMOS process is demonstrated for K-band applications. From the measurement results, the VCO exhibits a 510-MHz frequency tuning range at 20 GHz. The output power and the phase noise at 1-MHz offset are 3 dBm and 111 dBc/Hz, respectively. The fabricated circuit consumes a dc power of 32 mW from a 1.8-V supply voltage.application/pdf300960 bytesapplication/pdfzh-TWCapacitive feedbackCMOS radio frequency (RF)differential colpitts oscillatorsK-bandLC-tanklow phase noisevoltage-controlled oscillators (VCOs)journal article2-s2.0-85008048653WOS:000241009500010http://ntur.lib.ntu.edu.tw/bitstream/246246/200611150121768/1/174.pdf