Dumbbell annular ring with circular patterned microstrip low-pass filter with higher selectivity, wider stopband and lower insertion loss

Abstract

Electromagnetic Band Gap Structures (EBGs) have been developed to improve the efficiency of microwave and millimeter-wave devices, grown into most prominent framework by virtue of their unique electromagnetic and electrical properties. This article inspects the relationship between the operating performances of the low pass filter with the different EBG pattern. In this article, two high selectivity, wide stopband low pass filters (LPF) etched on ground plane with Tschebycheff polynomial distribution are proposed. A number of methods, method of moments (MOM) for numerical analysis and Tschebycheff polynomial distribution for designing the circuit are used. Moreover, to increase the stopband bandwidth of the new filters, a hybrid structure is used. The filter using ten dumbbell annular ring (DAR) patterns has improved selectivity of 47.19%, great matching upto 80 dB, negligible insertion loss less than 0.2 dB and two rejections in the stopband within 6.25 GHz, 12.97 GHz. In brief, this high selectivity, compact, wide stopband low pass filters were designed to alleviate the problem of low selectivity and small stopband bandwidth in microwave communication.