Tseng S.-KChiu C.-NTsao Y.-CYIH-PENG CHIOU2021-09-022021-09-02202100189375https://www.scopus.com/inward/record.uri?eid=2-s2.0-85101118159&doi=10.1109%2fTEMC.2020.3014215&partnerID=40&md5=a8e9bb8a1935c1f67b6a635acefa8ddbhttps://scholars.lib.ntu.edu.tw/handle/123456789/581235An ultrawideband absorptive common-mode filter (A-CMF) with a newly developed defected ground structure (DGS) is proposed in this article. The DGS miniaturized to a subwavelength size is able to totally suppress the common-mode noise while maintaining the signal integrity of the differential mode. In addition, the reflection and radiation of the common-mode noise are negligible in the stopband. For quick design, a simplified equivalent circuit model is also proposed. This model can be employed to estimate the resistances of the lumped resistors embedded in the DGS to obtain a very wide absorption band. In the demonstrated example, the fractional bandwidth determined by a 90% absorption efficiency can achieve as large as 104% around 3.55 GHz for an A-CMF realized on a simple two-layer printed circuit board. Such a widely absorptive bandwidth is never achieved before to our knowledge. The design methodology is validated by full-wave simulation. Finally, real measurement of the design is also carried out to confirm the design and analysis. ? 1964-2012 IEEE.Bandwidth; Defects; Equivalent circuits; Printed circuit boards; Structural design; Ultra-wideband (UWB); Absorption efficiency; Common mode noise; Common-mode filters; Design and analysis; Design Methodology; Equivalent circuit model; Fractional bandwidths; Full-wave simulations; Defected ground structures[SDGs]SDG7journal article10.1109/TEMC.2020.30142152-s2.0-85101118159