The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 17, 2004
Filed:
Jan. 24, 2002
Pengfei Zhang, Fremont, CA (US);
Chet Soorapanth, Mountain View, CA (US);
RF Micro Devices, Inc., Greensboro, NC (US);
Abstract
Circuits and methods for tuning voltage-controlled oscillators. A control voltage is applied through an isolation resistor to a varactor. The varactor capacitance is AC coupled through a second capacitance. The control voltage may be analog or digital. In a specific embodiment, multiple tuning diodes, and both analog and digital control voltages are used. The isolation resistor is outside the VCO tank circuit for low phase noise, excessive K is reduced, and the control and output voltages of the oscillator may swing over the entire supply range. The varactor capacitance may be junction, MOS, or other type of varactor.