A compact CPW-based dual-band filter using modified complementary split ring resonator

In this paper, a compact coplanar waveguide (CPW) based dual-band bandpass filter has been proposed. The modified complementary split ring resonator (CSRR) structure at CPW ground plane is investigated for designing of dual-band bandpass filter with minimum insertion loss. The zeroth order resonance (ZOR) frequency depends on shunt parameter due to open ended boundary condition. The dual-band bandpass filter with return loss 21 and 20 dB, insertion loss 0.5 and 0.4 dB at 1.8 and 3.2 GHz, respectively, are simulated and measured. The measured 3 dB fractional bandwidths are 92.7% and 18.8% with respect to their centre frequencies of passbands. The simulated and measured results are showing good agreement in the passband. The electrical size of designed filter is 0.10 lambda(0 )x 0.09 lambda(0) x 0.007 lambda(0), where lambda(0) is the free space wavelength at the resonance frequency of first pass band. It is suitable for a global system for mobile (GSM) and long term evolution (LTE) in different service bands of 900, 1800, 1900 and 2300 MHz wireless communication applications.