Avoiding RF Isolators - Reflectionless Filtering Components for Emerging Wireless Systems

RF isolators are usually employed in RF front-end chains to prevent active stages to be damaged by the presence of RF signal-power reflections created by the passive stages (e.g., RF bandpass filters) in their stopband regions. Indeed, such RF signal-power reflections may induce RF amplifiers to operate in the non-linear regime or to create additional undesired mixing products in frequency-conversion stages. Whereas passive and active RF isolators avoid this problem, this is done at the expense of higher size/volume and increased DC power consumption, respectively, and higher cost. A more-efficient solution that is recently gaining considerable research attention may be the exploitation of “reflectionless” RF passive devices, where the out-of-band signal energy is dissipated inside the circuit instead of being reflected back to the source so that RF isolators are no longer needed. The purpose of this webinar is to familiarize the audience with the emerging topic of reflectionless/absorptive RF passive components, which may result in considerable benefits for emerging RF front-end chains of new wireless systems (e.g., 5G and beyond) in terms of energy efficiency/DC-power-saving, overall size/volume, and cost. After introducing the problems of RF power reflections in RF front-end chains and classic solutions to circumvent them with their limitations, the main strategies for the design of reflectionless RF passive components as a new paradigm will be described. This includes both mono-functional and multi-functional RF devices in which several RF-analog-signal-processing actions are co-integrated together. Experimental results of several proof-of-concept demonstrators in a variety of technologies will be also presented.   

Speakers

Prof. Roberto Gomez-Garcia
University of Alcala

Roberto Gómez-García obtained his M. Sc. And Ph.D. degrees in electrical and electronic engineering from the Polytechnic University of Madrid, Madrid, in 2001 and 2006, respectively. He is now a Professor with the Department of Signal Theory and Communications, University of Alcalá, Alcalá de Henares, Spain. His research interests are in the areas of RF/microwave multi-functional and reconfigurable passive components, as well as RF sensors and SDR systems. In these topics, he has published about 120 journal articles and 150 conference papers. Dr. Gómez-García is also a member of various technical coordinating committees within IEEE MTT and CAS Societies. He was a recipient of the “2016 MTT-S Outstanding Young Engineer Award.” He has served/serves as an associate editor and a guest editor for several IEEE, IET, and EuMA journals. He has been appointed as IEEE CAS-S Distinguished Lecturer (2020-2022) and as Editor-in-Chief for IEEE Microwave and Wireless Components Letters (2022-2024).