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:
Apr. 06, 2010
Filed:
Jul. 27, 2007
Takehito Ishii, Saitama, JP;
Shunichi Wakamatsu, Saitama, JP;
Takehito Ishii, Saitama, JP;
Shunichi Wakamatsu, Saitama, JP;
Nihon Dempa Kogyo Co., Ltd., Tokyo, JP;
Abstract
To provide a Colpitts oscillation circuit formed with a quartz resonator and a transistor amplifier circuit, which can secure sufficient negative resistance, obtain stable oscillation, negate the need for an amplitude control circuit, and realize stabilization against temperature variations. In order to solve the problem, a structure in which the impedance of a tuning circuit provided in a collector of the transistor exhibits inductivity at the oscillation frequency is provided. The impedance ratio at the oscillation frequency of a capacitor Cconnected between a base and an emitter to a capacitor Cconnected between the emitter and a ground, of the transistor is set at 3 to 1 or more. Furthermore, the impedance of capacity Cconnected between the base and the emitter at the oscillation frequency is set at 300 Ω or more. A bias resistance Rconnected between the collector and the base of the transistor is set at 3 kΩ or less. A temperature compensation diode Dis inserted in series between the base and the ground (GND) between the transistor.