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 0.10λ0 × 0.09λ0 × 0.007λ0, where λ0 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.