Title: CMOS digital control LC oscillator on chip
Application Number: 200610011678 Application Date: 2006.04.14
Publication Number: 1832333 Publication Date: 2006.09.13
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: H03B5/12,H03L7/099
Applicant(s) Name: Tsinghua Univ. Address: 100084
Inventor(s) Name: Wang Shaohua
Attorney & Agent:
Abstract:
     This invention relates to a design technology for chips of T-R devices of the wireless communication system characterizing in applying a double-mode step-forward method composed of an technology-voltage-temperature calibration mode and a locking mode to get the assigned output oscillation frequency step by step, in which, in the calibration mode, a MIM switch condenser array controlled by digital signals is applied for frequency rough calibration in a rather wide sphere and in the locking mode, a MOS condenser matrix combining with a modulation mode of high speed digit sigma delta controlled by digital signals is applied to get an accurate output oscillation frequency in a rather wide sphere, especially a coupling mode of an improved MOS variable-capacitance diode is applied to reduce the sensitivity of oscillators to noises, at the same time, a sigma delta modulator of a single-step three-stages feedforward structure is applied to reduce the stray in output signals and a fixed differential capacitor of certain capacitance values is parallel to both ends of the variable-capacitance control circuit to reduce the phase noise of the oscillator and improve the linearity of frequency adjustment.
Time: 12