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. 23, 2005
Filed:
Nov. 13, 2003
Hiroyuki Ogiso, Ira, JP;
Hiroyuki Ogiso, Ira, JP;
Seiko Epson Corporation, , JP;
Abstract
A voltage-controlled oscillator includes a voltage-controlled phase-shift circuit for outputting a signal in which the phase of an input signal is shifted by a predetermined amount in accordance with an external control voltage; a plurality of SAW resonators, each of which resonates at a predetermined resonance frequency; switching means for selecting one of the plurality of SAW resonators in accordance with the external control signal; frequency selection means for selecting a predetermined resonance frequency from the selected SAW resonator; an oscillation differential amplifier for amplifying the resonance signal of the predetermined resonance frequency; and a feedback-buffer differential amplifier for inputting the output signal from the oscillation differential amplifier, wherein the voltage-controlled phase-shift circuit, the selected SAW resonator, the frequency selection means, the oscillation differential amplifier, and the feedback-buffer differential amplifier form a positive-feedback oscillation loop.