Differential microstrip lines with common-mode suppression based on electromagnetic band-gaps (EBGs)

A technique for the suppression of the common mode in differential (balanced) microstrip lines, based on electromagnetic band-gaps (EBGs), is presented in this letter. It is demonstrated that by periodically modulating the common-mode characteristic impedance of the line and simultaneously forcing t...

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Detalles Bibliográficos
Autores: Vélez, Paris|||0000-0001-6502-5987, Bonache Albacete, Jordi|||0000-0002-7225-5737, Martín, Ferran|||0000-0002-1494-9167
Tipo de recurso: artículo
Fecha de publicación:2015
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:163131
Acceso en línea:https://ddd.uab.cat/record/163131
https://dx.doi.org/urn:doi:10.1109/LAWP.2014.2354472
Access Level:acceso abierto
Palabra clave:Common-mode noise suppression
Differential transmission lines
Electromagnetic band-gaps (EBGs)
Periodic structures
Descripción
Sumario:A technique for the suppression of the common mode in differential (balanced) microstrip lines, based on electromagnetic band-gaps (EBGs), is presented in this letter. It is demonstrated that by periodically modulating the common-mode characteristic impedance of the line and simultaneously forcing the differential-mode impedance to be uniform (and equal to the reference impedance of the differential ports), the common mode can be efficiently suppressed over a certain frequency band, while the line is transparent for the differential-mode. The main advantage of EBGs, as compared to other approaches for common-mode suppression in differential microstrip lines, is the fact that the ground plane is kept unaltered. Moreover, the design of the differential line is straightforward since the required level of common-mode suppression and bandwidth are given by simple approximate analytical expressions. As a design example, we report a four-stage common-mode suppressed differential line with 68% fractional bandwidth for the common-mode stopband centered at 2.4 GHz, and maximum common-mode rejection ratio (CMRR) of 19 dB at that frequency. Furthermore, we have designed and fabricated a six-stage double-tuned common-mode suppressed differential line in order to enhance the stopband bandwidth for the common mode around 2.4 GHz.