Study of Hysteresis Loop and Concurrent Resonance with Multi-Band Voltage-Controlled Oscillators

• Main Authors: Chih-Chiang Kang, 康志強
• Other Authors: Sheng-Lyang Jang
• Format: Others
• Language: en_US
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/29352574988910477792

碩士 === 國立臺灣科技大學 === 電子工程系 === 104 === First, we study a new dual-band CMOS class-C voltage-controlled oscillator (VCO). The oscillator consists of a dual-resonance LC resonator in shunt with two pairs of capacitive cross-coupled nMOSFETs. The proposed oscillator has been implemented with the TSMC 0.18μm CMOS technology. The oscillator can generate differential signals at 2.4GHz and 6.9GHz and it also can generate concurrent frequency oscillation. With the supply voltage of VDD = 1.1 V, the VCO-core current and power consumption of the low/high-band oscillator are 2.90/1.14 mA and 3.19/1.25 mW, respectively. The die area of the concurrent oscillator is 0.9×0.97 mm^2. Secondly, we will briefly present a triple-band (TB) oscillator using two 4th order LC resonator to form a 6th order resonator. The TB oscillator uses a pair of cross-coupled nMOSFETs to emulate a negative differential resistance and two pairs of back-to-back varactors for band switching. The proposed oscillator has been implemented with CMOS devices in the TSMC 0.18μm SiGe 3P6M BiCMOS technology and the core oscillator current and power consumption at the high (middle, low)-band are 4.78(3.99, 4.36) mA and 3.824(3.192, 3.488) mW, respectively at the dc drain-source bias of 0.8V. The oscillator can generate differential signals in the frequency range of 8.25-8.64GHz, 6.87-6.90GHz, 4.63-4.80GHz and 4.24-4.50GHz, and the tuning range of oscillator shows the hysteresis effect. The die area of the triple-band oscillator is 1.045 × 1.064 mm^2. Finally, a mode-switched CMOS voltage-controlled oscillator (VCO) with two sub-frequency bands will be studied. The VCO consists of two cross-coupled VCOs coupled by a pair of mode-switched inductors. With the varactors as the mode switches, the VCO operates at the two different frequency bands. The proposed oscillator has been implemented with the TSMC 0.18μm CMOS technology. The oscillator can generate differential signals at 5.24GHz and 3.27GHz, and the core oscillator power consumption at the high/low-band is 4.68/6.85 mA and 3.557/5.206 mW, respectively at the dc drain-source bias of 0.76V, the hysteresis effect and concurrent oscillation are found. The die area of the dual-band VCO is 0.976×1.092mm^2.