Adaptive RF multi-interference suppression for wideband radar/communication receivers

In this chapter, a comprehensive review of recent contributions in the field of fully reconfigurable RF/microwave multi-notch filters is presented. These circuits are understood to be key components in future RF front-ends for wideband receivers to efficiently mitigate intentional and unintentional narrowband interference [18]. Specifically, tunable implementations for planar technologies are described in which the adaptive multi-notch filtering action is co-integrated with the wideband signal preselection process in a single dual-function RF filter. These filtering devices exploit different operating principles such as frequency-controllable circuit networks and coupled-resonator arrangements, whose advantages and disadvantages are discussed. Further, state-of-the-art mobile form factor high-Q filters for ultra-narrowband interference suppression based on mixed-technology acoustic-wave lumped-element resonators are also reported. A brief summary of future trends in this area is also provided at the end of the chapter.