A novel cross-coupled microstrip bandpass filter with hairpin-DGS resonators using coupling matrix technique

Abstract

This paper introduces a new design of a cross-coupled microstrip bandpass filter (MBPF) based on hairpin defected ground structure (DGS) resonators using accurate coupling matrix (CM) technique for microwave communication systems. The article presents the equivalent circuit of the suggested MBPF based on the DGS equivalent circuit model derived from the equivalent inductance and capacitance that occurs despite the presence of the slots disrupting the current in the ground layer. The paper investigates also the different external coupling mechanisms that the feed configuration affects significantly the filter response. In this paper, a four order Chebyshev topology has been adopted for designing the filter to suppress harmonics and achieve a very compact size and a wide stopband with two transmission zeros.

High isolation of SPDT PIN diode switch using switchable dumbbell-shaped DGS in millimeter wave 28 GHz band

“…In defected ground structure (DGS) design, currently it is commonly used in the application such as antennas [2]- [4], microwave filters [5]- [7], and the latest trend in microwave sensors [8], [9]. The progression of research works on the DGSs in RF and microwave for the last 10 years have shown evidences of improvement towards design realizations and performances.…”