Title :
Design of a 4 GHz quadrature LC -VCO with transformer coupling
Author :
Xiushan, Wu ; Zhigong, Wang ; Zhiqun, Li ; Qing, Li
Author_Institution :
Coll. of Electr. & Mech. Eng. of China, Jiliang Univ., Hangzhou
Abstract :
A 4 GHz quadrature voltage-controlled oscillator (QVCO) topology is proposed where a planar spiral transformer is used as coupling terminals. Two identical LC oscillators are cross-coupled by the transformer to generate the quadrature outputs. The transformer also serves as filtering network for the oscillators to improve the phase noise performance. The quadrature oscillator based on the proposed topology with additional design ideas has been implemented in a 0.18 um mixed-signal 1P6M CMOS technology for 4 GHz-band operation. The simulation gave a phase noise of -122 dBc/Hz at 1 MHz offset with an output power of 1 dBm, while dissipating 7.8 mA under a 1.8 V supply.
Keywords :
CMOS integrated circuits; MMIC oscillators; couplings; integrated circuit design; mixed analogue-digital integrated circuits; phase noise; transformers; voltage-controlled oscillators; current 7.8 mA; filtering network; frequency 1 MHz; frequency 4 GHz; phase noise performance; planar spiral transformer; quadrature LC-VCO; quadrature voltage-controlled oscillator topology; size 0.18 mum; transformer coupling; voltage 1.8 V; CMOS technology; Educational institutions; Mechanical engineering; Network topology; Phase noise; Power dissipation; Ring oscillators; Signal generators; Transceivers; Voltage-controlled oscillators;
Conference_Titel :
Microwave and Millimeter Wave Technology, 2008. ICMMT 2008. International Conference on
Conference_Location :
Nanjing
Print_ISBN :
978-1-4244-1879-4
Electronic_ISBN :
978-1-4244-1880-0
DOI :
10.1109/ICMMT.2008.4540536
