公开(公告)号：EP1671422B1

公开(公告)日：2017-04-12

申请号：EP04793967.3

申请日：2004-10-01

申请人： MediaTek Inc.

发明人： BALBONI, Edmund, J. ,  PALMER, Wyn, T. ,  STRANGE, Jonathan, R.

IPC分类号： H03L7/093

CPC分类号： H03L7/1976 ,  H03C3/0925 ,  H03C3/0933 ,  H03C3/0941 ,  H03C3/095 ,  H03J3/00 ,  H03L7/0805 ,  H03L7/0893 ,  H03L7/0898 ,  H03L7/093 ,  H04L2027/0081

公开(公告)号：EP1216501B1

公开(公告)日：2010-11-10

申请号：EP00967058.9

申请日：2000-09-28

申请人： MediaTek Inc.

发明人： GOLDFARB, Marc, E. ,  PALMER, Wyn, T.

IPC分类号： H03B1/00 ,  H04B1/10 ,  H04L27/227 ,  H03H11/12

CPC分类号： H03H11/1217 ,  H04B1/30

摘要： A direct conversion receiver (10) having a homodyning section (12) and a filter (18). The filter (18) includes a plurality of serially coupled high pass filter stages (20(1)-20(n)). The high pass filter section (18) act as a dc offset correction loop. The plurality of high pass filter stages (20(1)-20(n)) also enables the integration of the needed capacitors thus minimizing external components and connections. Each one of the filter stages includes an amplifier (22) and a low pass filter (24). Each one of the low pass filters (24) is adapted to have the cutoff frequency thereof switch from an initial high cutoff frequency to a subsequent lower cutoff frequency. A high pass filter stage (20(1)-20(n)) of a direct conversion receiver (10) is provided which includes in a low pass filter feedback section (24) thereof: a capacitor (C) and a resistor section (30). The resistor section (30) includes a switch for changing the resistance of the resistance section. A switching arrangement (32) is included for charging the capacitor (C) rapidly during an initial, start-up time period or after a large step change in the gain of the amplifier (22).