Invention Grant
- Patent Title: Frequency generator and communication system using the same
- Patent Title (中): 频率发生器和通信系统使用相同
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Application No.: US10901966Application Date: 2004-07-30
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Publication No.: US07177612B2Publication Date: 2007-02-13
- Inventor: Takahiro Nakamura , Kenichi Ohhata , Toru Masuda
- Applicant: Takahiro Nakamura , Kenichi Ohhata , Toru Masuda
- Applicant Address: JP Tokyo
- Assignee: Renesas Technology Corp.
- Current Assignee: Renesas Technology Corp.
- Current Assignee Address: JP Tokyo
- Agency: Antonelli, Terry, Stout and Kraus, LLP.
- Priority: JP2003-305009 20030828; JP2004-187412 20040625
- Main IPC: H04B7/00
- IPC: H04B7/00 ; H04B1/18 ; H04B1/16

Abstract:
A frequency generator which can perform stable frequency oscillation unaffected by temperature variation.A frequency generator having a differential amplifier (1) having an LC resonance circuit (10) as a load and buffer circuits (21, 22) feeding back an output of the differential amplifier to its input, wherein a temperature coefficient converter (5) converting an output voltage of a reference voltage generator (4) and its temperature dependence to a voltage having a predetermined voltage and temperature coefficient and outputting it is provided to control bias currents IEF of emitter follower circuits to be in proportion to temperature variation. There are a characteristic in which delay time of the emitter follower circuits constructing the buffer circuits is in inverse proportion to a transconductance of transistors and a characteristic in which the transconductance is in inverse proportion to temperature and is in proportion to the bias currents IEF. An oscillation frequency stable to temperature variation can be obtained.
Public/Granted literature
- US20050059373A1 Frequency generator and communication system using the same Public/Granted day:2005-03-17
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