New concepts for absorptive RF filtering and coupling-less RF tuning
This talk presents state-of-the-art reconfigurable filtering components with reflectionless/absorptive behavior and static couplings. The avoidance of signal-power reflections in the out-of-band regions of these filtering circuits can considerable alleviate the need of bulky isolators and circulators in the complete RF chain. On the other hand, the realization of the transfer-function adaptivity without the need of variable couplings results in lower-loss and higher-linearity filtering devices. The theoretical foundations of the described filter approaches are presented. Furthermore, a variety of experimental prototypes in different technologies with controllable single- and multi-band operation are shown as proof-of-concept demonstrators.