Novel cross-coupled microstrip bandpass filter with hairpin-DGS resonator using coupling matrix technique
This paper introduces a new method of the BPF design has adopted which is the defected ground structure (DGS). A new type of microstrip BPF based on coupled DGS resonators is designed using coupling matrix method. We also presented, the equivalent circuit of the proposed BPF based on the equivalent circuit model of the DGS, which is derived from the equivalent inductance and capacitance that appeared due to the perturbed ground current in the ground plane due to the presence of the slot.We introduce new compact Hairpin-DGS resonators and investigate different external coupling mechanisms; we show that the feed configuration affects the response of the filter rather significantly. A four order filter with chebyshev responses has been proposed to suppress harmonics. The new BPF is very compact, in addition, the ﬁlter has a very wide stopband with two transmission zeros.