A compact SIW based filtering power divider with improved selectivity using CSRR

A compact substrate integrated waveguide based power divider with bandpass filtering response using metamaterial structure is presented in this paper. The proposed structure has composed with two complementary split ring resonator (CSRR) separated by an interdigital capacitor and both the CSRR uses total six via to connect top and ground plane. The CSRR is obtained by etching the split ring resonator (SRR) from the rectangular metallic patch. The SRR has composed with combination of a U-type ring and open ended rectangular ring. The use of CSRR permits filtering response and provides compactness. The metamaterial properties of designed structure has been verified by its dispersion diagram. The electrical size of the proposed filtering power divider is 0.07λ
_g
× 0.16λ
_g
, where λ
_g
is the guided wavelength at ZOR frequency (f
₀
), 1.54 GHz. The ZOR frequency mainly depends on the length of interdigital capacitor (L
_idc
). The frequency of transmission zeros have been achieved at 0.85GHz, 2.28GHz, and 4.9 GHz respectively, which can be controlled by varying the parameters of CSRR. The designed structure gives wide stopband with high selectivity. The selectivity of proposed structure have 116 dB/GHz and 82 dB/GHz at the lower and upper side of the passband with wide stopband region extends up to 3.45f
₀
below 20 dB. The proposed structure has designed and simulated by ANSYS high frequency structural simulator HFSS 14.0 using Rogers RT/Duriod 6010 substrate with dielectric constant 10.2 and thickness 1.27 mm. The proposed structure is suitable for global positioning system (GPS) application.