Active continuous-time filter with increased dynamic range in the presence of blocker signals

摘要

An active filter (100) is disclosed with improved blocker signal rejection characteristics. Linear resistors, such as fixed value resistors (3, 4) are used at the input stage (72) of the filter (100) to suppress any blocker signal. A gain compensation stage (57) is added to the output stage (23) using resistors (24) fabricated with the same technology used to fabricate the input resistors (3, 4) in order to offset any gain changes associated with the input fixed value resistors (3, 4). In an exemplary embodiment, the fixed value resistors (3, 4) are fabricated using polysilicon.