Practical Design of Filters Using Ebg Waveguides Periodically Loaded With Metal Ridges

Abstract

Abstract-The dispersion diagram of infinite periodic structures is useful for the practical design of waveguide filters. Starting from the dispersion diagram of a unit cell, it is possible to generate a finite structure with very similar pass-and stop-bands (gaps). However, truncation of the infinite periodic structure degrades the pass-band performance. In this paper, these impairments are overcome by means of suitable waveguide tapers matching the impedance of the periodic structure to the access ports. As a result, the design of practical low-pass filters, derived from passive structures based on Electromagnetic Band-Gap (EBG) waveguides periodically loaded with metal ridges, is successfully addressed. According to this procedure, a five-order and an eight-order EBG low-pass filters are obtained after an optimization step. Measurements of a manufactured prototype fully validate the proposed approach.

Band-pass filters based on periodic structures in SIW technology

“…In order to characterize a periodic structure in the frequency domain, the dispersion diagram associated to its unit cell must be calculated [1], [23]. This has been done for the two periodic structures presented in this work by using the commercial software tool Ansys HFSS (see, for instance, [15], [24]).…”

“…Periodic structures in waveguiding systems (also called Electromagnetic Band Gap (EBG) structures) show very attractive filtering properties in the frequency domain associated with the appearance of permitted and forbidden frequency bands in their dispersion diagram, yielding size reduction and rejection band improvement. There are many examples of periodic structures with filtering applications [1]- [6].…”

Resonant Quasi-Periodic Structure for Rectangular Waveguide Technology With Wide Stopband and Band-Pass Behavior

“…The study and development of periodic structures for waveguide technologies has always been an important research topic in the microwave community [1]. The filtering properties of these structures continue providing new tools for the design of devices with stringent specifications [2]. Initially, the constituent unit cells of the periodic structures presented sharp discontinuities [3].…”