A wireless receiver includes a down converter module operable to deliver a signal having a signal bandwidth that changes over time, a dynamically controllable filter module having a filter bandwidth and fed by said down converter module, and a measurement module operable to at least approximately measure the signal bandwidth, said dynamically controllable filter module responsive to said measurement module to dynamically adjust the filter bandwidth to more nearly match the signal bandwidth as it changes over time, whereby output from said filter module is noise-reduced. Other wireless receivers, electronic circuits, and processes for their operation are disclosed.