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. 19, 2003
Filed:
Oct. 30, 2001
Mau-Chung F. Chang, Los Angeles, CA (US);
Yi-Cheng Wu, West Los Angeles, CA (US);
G-Plus, Inc., Santa Monica, CA (US);
Abstract
An active inductor circuit includes a primary and a secondary coil and a drive circuit monolithically integrated on a common substrate to provide high-Q inductors. Each inductor circuit comprises a primary coil which carries a first current that varies with an RF input signal, and a secondary coil which carries a second current that varies with the RF input; an on-chip current source provides the second current. The inductor circuit is arranged such that there is a fixed phase difference of approximately 90° between the first and second currents, and such that the magnetic field induced by the second current compensates for energy that would otherwise be dissipated by the primary coil. When the second current is properly selected, the inductor circuit's input impedance is made purely imaginary, such that the circuit emulates an ideal inductor at a particular frequency.