发明名称 AM/FM RADIO RECEIVER AND LOCAL OSCILLATOR CIRCUIT USED THEREIN
摘要 A couple of frequency doubler circuits 21 and 22 which multiplys a frequency of a reference oscillation signal outputted from a reference oscillator 12 is provided, thereby a frequency of a reference oscillation signal, as the greatest common divisor between a frequency (300 KHz) determined by multiplying the frequency (fx=75 KHz) of a crystal oscillator 11 by four and a frequency (54 KHz) determined by multiplying an assigned frequency per one channel in AM radio broadcasting by a prescribed divide ratio, can be higher than a conventional frequency. This way realizes the decrease of a divide ratio in a programmable counter 17, resulting in the reduction of the circuit scale, shortening of the lock-up time, and improvement of the S/N ratio.
申请公布号 US2006199555(A1) 申请公布日期 2006.09.07
申请号 US20060383087 申请日期 2006.05.12
申请人 NIIGATA SEIMITSU CO., LTD. 发明人 IKEDA TAKESHI;MIYAGI HIROSHI
分类号 H04B1/18;H03J5/02;H03J5/24;H03L7/07;H03L7/181;H04B1/06 主分类号 H04B1/18
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