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. 29, 2011
Filed:
Mar. 17, 2009
Voltage controlled oscillator, and pll circuit and wireless communication device each using the same
Takayuki Tsukizawa, Osaka, JP;
Takayuki Tsukizawa, Osaka, JP;
Panasonic Corporation, Osaka, JP;
Abstract
A voltage controlled oscillator includes first and second variable capacitance circuits 120 and 130, and first and second capacitance switch circuits 140 and 150. A control voltage Vt is fixedly applied to the first variable capacitance circuit 120, and control signals Fsel2 and Fsel3 are fixedly applied to the first and second capacitance switch circuits 140 and 150, respectively. When both of the control signals Fsel2 and Fsel3 are at a low level, the control signal Fsel1 is applied to the second variable capacitance circuit 130. When the control signals Fsel2 and Fsel3 are both not at the low level, the control voltage Vt is applied to the second variable capacitance circuit 130. As a result of this control, a high-frequency variable range is divided into two variable ranges, one based on upper frequencies and the other based on lower frequencies. This enables suppression of a frequency sensitivity without narrowing the high-frequency variable range.