| 摘要 |
<p>The specification and drawings present a new apparatus and method for an RF tracking filter which may be used in RF transceivers. Instead of having band pass filter and switches in the signal path exemplary embodiments of the invention describe keeping the signal path (15) intact for wanted frequency components and drawing selectively signal energy (e.g., corresponding to unwanted frequency components) from the signal path (15). This may be done with a shunt passive switch (20) comprising multiple switches for generating commutated signals of the radio frequency signal. Behind the switches (20) there may be a plurality of active feedback loops (22), each drawing a frequency dependent current for one of the one or more commutated signals and feeding the drawn current back to the passive input switch (20) to cancel only the unwanted frequency components of the radio frequency signal.</p> |
