Title :
Tuning-Range Enhancement Through Deterministic Mode Selection in RF Quadrature Oscillators
Author :
Bagheri, Mahdi ; Bagheri, Rahim ; Buckwalter, James F. ; Larson, Lawrence E.
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of California at San Diego, La Jolla, CA, USA
Abstract :
Quadrature oscillators (QOs) based on parallel or series coupling mechanisms produce ambiguous phase relationships between the coupled oscillators. Deterministic mode selection is presented and analyzed for a series-coupled LC quadrature oscillator ( LC-QO) and leveraged to increase the tuning range of the QO. Series-coupled LC-QOs have been implemented in a 90-nm CMOS technology. Measured results show a frequency tuning range of 94% for a center frequency of 1.3 GHz, 60% for the oscillator operating at 3.7 GHz, and 52% for the oscillator operating at 4.4 GHz.
Keywords :
CMOS integrated circuits; LC circuits; MMIC oscillators; UHF oscillators; circuit tuning; coupled circuits; CMOS technology; RF quadrature oscillators; coupled oscillators; deterministic mode selection; parallel coupling; series coupling; series-coupled LC quadrature oscillator; series-coupled LC-QO; size 90 nm; tuning-range enhancement; Couplings; Impedance; Phase noise; Phase shifters; Quality of service; Tuning; Oscillator; phase noise; quadrature; tuning range;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
DOI :
10.1109/TMTT.2015.2478787
