Microwave filter design using radial line stubs

Abstract

The design of microwave filters using radial line stubs as reactive elements is investigated. To reduce the design complexity, a simplified model for radial line stub reactance versus frequency is first developed. This allows for an easy transition from the lowpass prototype to the desired planar circuit elements. The frequency-response characteristic of specific radial line stub filter is compared to ideal lumped-element equivalents, and also planar circuit realizations using more traditional straight transmission line elements.<>