Full-wave design of spurious free DR TE mode band pass filters

Abstract

Analytic full-wave analysis and design of direct-coupled dielectric loaded bandpass filters in rectangular waveguide configuration using the TElo mode with a spurious-free response up to twice the operating frequency is described. The Mter has no tuning screws and is small in size. Theoretical design of the filter is supported by the experimental results. Superiority of the filter over the inductive window-coupled filter is presented. Practical issues faced while building the filter are discussed. An alternative folded configuration of the filter that allows the implementation of both the canonical elliptic function as well as the Chebychev response is also presented.

Harmonic Characterizations of Loaded Resonators for Waveguide Filters

“…Similarly, with methods where multiple dielectric materials [19], mixed-mode [22] or mixed resonators [24] are utilized for their resonators, the dimensions and materials of the input/ output resonators port would require additional designing. Hence, the coupling inverters for bandpass filter implementations require extra design effort, increasing the design and fabrication complexity.…”

“…Ridge waveguide bandpass filter structures were also utilized to lower the fundamental mode frequency and thus increase the spurious-free frequency range [16]- [18]. Different coupling techniques were explored by changing the dielectric constant of the coupler, employing mixed-mode coupling, and using non-resonating nodes as couplers for wider spurious free stopband [19]- [21]. Designs that mix resonators with different harmonic frequencies were also investigated [22], [23].…”

Design and analysis of iris-coupled and dielectric-loaded 1/8-cut TE/sub 01/-mode microwave bandpass filters

“…It is also possible to use the standard design technique of waveguide resonator filters to design the class of iris-coupled and dielectric-loaded resonators considered in this paper. This approach was used in designing -plane dielectric waveguide filters [9] as well as -mode dielectric-loaded rectangular filters [10]. Within this framework, it is possible to determine accurately the coupling between the resonators while taking into account its effect on the resonant frequencies of the resonators.…”