Compact metamaterial inspired dual-band bandpass filter using parallel coupled line and circular shaped stub

This paper presents a metamaterial inspired dual-band bandpass filter. The filter discussed is constructed using two parallel-coupled lines, interconnected with two circular shaped stubs. The designed filter offers a 3 dB fractional bandwidth of 70.6% and 26.2% with centre frequencies of 1.77 GHz and 4.13 GHz for first and second pass band. Both the pass bands are separated by a stop band of 1.2 GHz. This filter offers compactness with electrical size of 0.10λ
0
×0.08λ
0
, given λ
0
is wavelength in free space at centre frequency of first passband. The average group delay for both the pass bands are 0.4 ns and 0.6 ns respectively. The modeling of proposed filter is carried out by high frequency structural simulator ANSYS HFSS 14.0 3D software. It is useful in global systems for mobile communications (GSM) at 1800 MHz and fixed satellite service (3.7–4.2 GHz).