The design of passive filter networks has traditionally been a process in which approximations are made to a desired transfer function using reactive and resistive elements exhibiting the same frequency-dependent functional form. Over the years, a variety of synthesis techniques have been developed that allow for extracting sets of such elements from the transmission and reflection functions associated with approximating the desired transfer function when terminated with a specified source and load impedance. We know that physically it is not difficult to combine lumped, distributed and evanescent elements in the same network. Optimization allows for insertion of elements with different frequency dependencies, but exact synthesis is generally not possible. This presentation will address present approaches and will provide insight into future design approaches.
Notch filters are increasingly important components in high power communication systems. Cosite interference analog suppression techniques depend heavily on eliminating emission of spurious high power signals at the source, or suppressing such signals prior to a receiver. Understanding and enhancing the ability of notch filters to survive exposure to high RF power is the subject of this presentation. The power handling capability of bandpass and lowpass filters has been studied and much published material is readily available. However, bandstop and highpass filters have not been studied as thoroughly (or public results are not as easy to find). In this presentation, we will present the basic computational basis for determining power handling and suggest methods for increasing the breakdown and/or heat-related failure thresholds.