Microstrip low pass filter with wideband rejection using opened circuit stubs and Z‐slots defected ground structures

Abstract

A new microstrip low pass filter (LPF) with defected ground structure (DGS) is proposed in this article.The DGSs consists of reshaped rectangular dumbbell slot and four groups of Z‐shape slots. The microstrip line with DGS gave good rejection band extend from 3.0 to 9 GHz with acceptable pass band. The microstrip line with open circuit stubs (without DGS) gave good rejection band at the high frequency from 9 to 14 GHz. Using both structures results in LPF with wideband rejection from 3.37 to 14 GHz with attenuation less than (−26.0dB) and good passband less than (−25 dB). An equivalent circuit for the proposed LPF was given. The realized filter size was 34.0 × 34.0 mm2, and it gave good agreement with simulated results. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:811–815, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25876

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Compact lowpass filter with a sharp roll‐off using patch resonators

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