公开(公告)号：US20110026507A1

公开(公告)日：2011-02-03

申请号：US12789771

申请日：2010-05-28

申请人： Yusaku KATSUBE ,  Junichi TAKAHASHI ,  Masaaki YAMADA ,  Toshihito HABUKA ,  Kenichi SHIBATA ,  Fumihito YAMAGUCHI

发明人： Yusaku KATSUBE ,  Junichi TAKAHASHI ,  Masaaki YAMADA ,  Toshihito HABUKA ,  Kenichi SHIBATA ,  Fumihito YAMAGUCHI

IPC分类号： H04W88/02 ,  H03H7/01 ,  H04B1/16

CPC分类号： H04B1/30 ,  H03H7/0153 ,  H03H11/1291 ,  H03H2210/012 ,  H03H2210/025 ,  H03H2210/036 ,  H03H2250/00

摘要： Gain setting can be performed at high speed while reducing DC offset due to a filter cutoff frequency changeover without the need for input signal muting. A filter circuit having first and second filters is capable of allowing settings of first and second cutoff frequencies. First and second filter switch circuits and a charging circuit including a charging resistor and a charging switch are provided. For a first time period, the first switch circuit is controllably turned on while the second switch circuit is controllably turned off, thereby providing the first filter function. For a second time period, the first switch circuit is controllably turned off while the second switch circuit is controllably turned on, thereby providing the second filter function. For the first time period, the charging switch is controllably turned on so that the second capacitor is charged via the charging resistor.

摘要翻译： 增益设置可以高速执行，同时减少由于滤波器截止频率切换引起的直流偏移，而不需要输入信号静音。 具有第一和第二滤波器的滤波器电路能够允许第一和第二截止频率的设置。 提供第一和第二滤波器开关电路以及包括充电电阻器和充电开关的充电电路。 在第一时间段中，第一开关电路被可控地导通，而第二开关电路被可控地关断，从而提供第一滤波器功能。 对于第二时间段，第一开关电路在第二开关电路被可控地接通的同时被可控制地截止，从而提供第二滤波器功能。 在第一时间段中，充电开关被可控地导通，使得第二电容器经由充电电阻器充电。

公开(公告)号：US20090258626A1

公开(公告)日：2009-10-15

申请号：US12419355

申请日：2009-04-07

申请人： Masaaki YAMADA ,  Yusaku KATSUBE ,  Junichi TAKAHASHI ,  Toshihito HABUKA ,  Fumihito YAMAGUCHI

发明人： Masaaki YAMADA ,  Yusaku KATSUBE ,  Junichi TAKAHASHI ,  Toshihito HABUKA ,  Fumihito YAMAGUCHI

IPC分类号： H04B1/06 ,  H03H7/00 ,  H04B1/16

CPC分类号： H03H7/0153 ,  H03H7/1708 ,  H03H7/24 ,  H03H7/425

摘要： A filter circuit includes first capacitors, second capacitors capable of altering a cutoff frequency by being connected in parallel with the first capacitors, first switches for connecting the second capacitors in parallel with the first capacitors, and charging circuits for the second capacitors. The charging circuits include second switches, and resistances for attenuating the amplitudes of input voltages to be fed to the second capacitors, by being connected in series with the second capacitors. The second capacitors are charged through the resistances in a state where the first switches are turned OFF and where the second switches are turned ON. Thus, a DC offset which is ascribable to the cutoff frequency switching of a filter is reduced.

摘要翻译： 滤波器电路包括第一电容器，能够通过与第一电容器并联连接来改变截止频率的第二电容器，用于将第二电容器与第一电容器并联连接的第一开关和用于第二电容器的充电电路。 充电电路包括第二开关和用于衰减要馈送到第二电容器的输入电压的振幅的电阻，通过与第二电容器串联连接。 在第一开关断开的状态和第二开关导通的状态下，通过电阻对第二电容器进行充电。 因此，降低了归因于滤波器的截止频率切换的DC偏移。

公开(公告)号：US20090080577A1

公开(公告)日：2009-03-26

申请号：US12276532

申请日：2008-11-24

申请人： Toshihito HABUKA ,  Naoto INOKAWA ,  Kiyoharu OZAKI ,  Tatsuji MATSUURA ,  Koichi YAHAGI

发明人： Toshihito HABUKA ,  Naoto INOKAWA ,  Kiyoharu OZAKI ,  Tatsuji MATSUURA ,  Koichi YAHAGI

IPC分类号： H04L27/08

CPC分类号： H04L27/3809 ,  H03G3/3068 ,  H04L25/061 ,  H04L27/2647

摘要： A D.C. offset canceling and gain adjusting techniques permitting completion of correction of D.C. offsets and gain adjustment of amplifiers for amplifying reception signals in a radio communication system are provided. A communication semiconductor integrated circuit has a plurality of low-pass filters and variable gain amplifiers which are alternately connected in multiple stages, and high gain amplifier circuits for amplifying reception signals to a predetermined amplitude level. Offset cancellation values are generated by detecting D.C. offsets of amplifiers for amplifying reception signals according to a set gain, and stored into a memory, and read out of the memory to cancel the D.C. offsets of the amplifiers when starting reception and altering the gain. Gain setting in a high gain amplifying section is accomplished using rough and precise settings.

摘要翻译： 提供了D.C.偏移消除和增益调整技术，其允许完成D.C.偏移的校正和用于在无线电通信系统中放大接收信号的放大器的增益调整。 通信半导体集成电路具有多个交替连接的多个低通滤波器和可变增益放大器，以及用于将接收信号放大到预定幅度电平的高增益放大器电路。 通过根据设定的增益检测用于放大接收信号的放大器的直流偏移量，并将其存储到存储器中，并从存储器中读出以消除开始接收和改变增益时放大器的直流偏移量来产生偏移抵消值。 高增益放大部分的增益设置是通过粗略和精确的设置实现的。