Wideband Bandpass Filters Using a Novel Thick Metallization Technology

Abstract

A new class of wideband bandpass filters based on using thick metallic bars as microwave resonators, instead of common microstrip lines, is presented. These bars provide a series of advantages over fully planar printed technologies, including higher coupling levels between resonators, better unloaded quality factors Q U , and larger bandwidths, implemented with more compact structures. Moreover, thick bar resonators can easily be coupled to an additional resonance excited in a box used for shielding, allowing to realize transversal topologies able to implement transmission zeros at desired frequencies. To illustrate the capabilities of this technology, two microwave filters with different bandwidths and one transmission zero have been designed. One of the filters has been manufactured and tested using copper bars inside an aluminum housing partially filled with Teflon. Measured data demonstrates a fractional bandwidth about FBW = 32%, spurious free range SFR > 50%, unloaded quality factor of Q U = 1180 and return losses over 20 dB without requiring any post-tuning on the prototype, confirming the exciting performance of the proposed technology.Index Terms-Hybrid waveguide microstrip technology, microwave filters, resonator filters, transmission zeros, transversal filters, wideband filters.

Multimode Equivalent Networks for Shielded Microwave Circuits With Thick Metallizations

“…1. The filters are described in detail in [19]. A general schematic of the structure under analysis is shown in Fig.…”

“…In this situation, the thickness becomes electrically important and, therefore, it must be included explicitly in the computations in order to obtain accurate results. Furthermore, a new class of thick bar resonators has been recently proposed to implement wideband filters [19]. The thicker metallic resonators exhibit better unloaded quality factors than regularly printed microstrip resonators.…”

Investigación en técnicas numéricas basadas en ecuación integral para el análisis y diseño de dispositivos de microondas para comunicaciones espaciales

“…In this case, the thickness becomes electrically important and therefore it has to be considered for an accurate analysis. Moreover, a new type of wideband filters Gomez- Molina et al (2020d) are implemented using bulky metallic bar resonators. In this case, the thickness of the resonators is also electrically large even at microwave frequencies.…”

“…The articles related to this chapter that have been published in technical journals or international conferences are: Gomez- Molina et al (2020d) and Gomez-Molina et al (2020a).…”

“…In this situation, the thickness becomes electrically important and, therefore, it must be explicitly included in the computations in order to obtain accurate results. Furthermore, a new class of thick bar resonators has been recently proposed to implement wideband filters Gomez- Molina et al (2020d). The thicker metallic resonators exhibit better unloaded quality factors than regular printed microstrip resonators.…”