公开(公告)号：EP1069681A2

公开(公告)日：2001-01-17

申请号：EP00305019.2

申请日：2000-06-14

申请人： ALPS ELECTRIC CO., LTD.

发明人： Noumi, Hiroki, c/o Alps Electric Co., Ltd ,  Baba, Toshiki, c/o Alps Electric Co., Ltd

IPC分类号： H03J5/24

CPC分类号： H03J5/24

摘要： Disclosed herein is a frequency-characteristic switchable buffer circuit (1) capable of increasing attenuation of a spurious frequency signal upon selection of a second frequency signal. The frequency-characteristic switchable buffer circuit includes an amplifying stage (2), a parallel resonance circuit (3) which serves as an output load of the amplifying stage, a frequency trap circuit (6) electrically connected between the input of the amplifying stage and a reference potential point, and a frequency switching voltage generator (20,21) for selectively generating a first switching voltage or a second switching voltage. The parallel resonance circuit parallel-resonates at a first frequency when the first switching voltage is supplied thereto. When the second switching voltage is supplied thereto, the parallel resonance circuit parallel-resonates at a second frequency. The frequency trap circuit comprises a series circuit made up of a diode (6 2 ) and a capacitor (6 1 ). When the first switching voltage is supplied to the frequency trap circuit, the frequency trap circuit series-resonates at a frequency lower than the first frequency. When the second switching voltage is supplied thereto, it series-resonates at any of frequencies lying within at 1700MHz band, which is higher than the second frequency.

摘要翻译： 本文公开了一种频率特性可切换缓冲器电路（1），其能够在选择第二频率信号时增加寄生频率信号的衰减。 频率特性可切换缓冲电路包括放大级（2），作为放大级的输出负载的并联谐振电路（3），电连接在放大级的输入与放大级之间的频率陷波电路（6） 参考电位点和频率切换电压发生器（20,21），用于选择性地产生第一切换电压或第二切换电压。 并联谐振电路在提供第一开关电压时以第一频率并联谐振。 当提供第二开关电压时，并联谐振电路以第二频率并联谐振。 频率陷波电路包括由二极管（62）和电容器（61）组成的串联电路。 当第一开关电压被提供给频率陷波电路时，频率陷波电路以低于第一频率的频率串联谐振。 当提供第二开关电压时，它在位于比第二频率高的1700MHz频带内的任何频率处串联谐振。