This paper describes a novel technique to realize a high-Q, integratable notch filter for image frequency rejection in superhetrodyne receivers. This integratable filter can be realized using either active and/or passive components. The primary advantage of this notch filter design is its relative insensitivity to the Q values of the passive reactive components. By simple tuning of a passive component, the filter shows a high-Q notch for any value of inductor and capacitor Q. The technique is also applicable to poly-phase (complex) filters. Example filters are simulated and results are shown to validate the concept. Simulation results at 2.5 GHz show more than 100 dB of image rejection ratio (IRR) for a system with an intermediate frequency (IF) of 300 MHz. This is an improvement of 20 dB over any reported results thus far for similar frequency specifications.
|Original language||English (US)|
|Journal||Proceedings - IEEE International Symposium on Circuits and Systems|
|State||Published - Jul 14 2003|
|Event||Proceedings of the 2003 IEEE International Symposium on Circuits and Systems - Bangkok, Thailand|
Duration: May 25 2003 → May 28 2003