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:
Nov. 15, 2005
Filed:
Sep. 06, 2001
Kazuharu Aoki, Fukushima-ken, JP;
Kazuharu Aoki, Fukushima-ken, JP;
Alps Electric Co., Ltd., Tokyo, JP;
Abstract
A frequency synthesizer includes a first oscillator that outputs a first oscillation signal. A first phase shifter outputs two first signals which are out of phase by 90°. A second oscillator outputs a second oscillation signal. A second phase shifter outputs two second signals which are out of phase by 90°. To a first mixer, one of the first signals and one of the second signals are input. To a second mixer, the other one of the first signals and the other one of the second signals are input. An adder adds combined outputs from the first and second mixers. A phase switching device changes the phase relationship between the two first signals or the two second signals input to the first mixer and the second signal. An input allowing/prohibiting switching device allows or prohibits the second signals from being input to the first and second mixers. The adder outputs one of a signal at the same frequency as that of the first oscillation signal, a signal at the sum frequency of the frequencies of the first oscillation signal and the second oscillation signal, and a signal at the difference frequency between the frequencies of the first oscillation signal and the second oscillation signal.