Receiver apparatus having filters implemented using frequency translation techniques

摘要

A method and apparatus is disclosed to effectively frequency translate a filter characterized as a low quality factor (Q) filter, corresponding to a baseband frequency of approximately zero Hertz or to an intermediate frequency (IF), to a filter characterized as a high Q filter at frequencies greater than the baseband frequency or the IF. A downconversion mixer frequency translates a communication signal to the baseband frequency or the IF using a first local oscillator signal to provide a downconverted communication signal. A filter corresponding to the baseband frequency or the IF filters the downconverted communication signal to provide a filtered communication signal. An upconversion mixer frequency translates a communication signal using a second local oscillator signal. The frequency translation by the upconversion mixer, in effect, translates the filter characterization from the low Q filter to the high Q filter at frequencies greater than the baseband frequency or the IF.