Multi-wideband bandpass filter using meandered stub-stepped impedance resonators for multiband application

This paper proposes a multi-wideband bandpass filter (MW-BPF) using meandered stub-stepped impedance resonators (MS-SIR). This research shows that MS-SIR resonator not only generate five-pass bands, but it also yields wide-fractional bandwidth, good transmission coefficients, and ease of fabrication. A transmission line analysis was used to design and to investigate the filter structure. Furthermore, this filter was fabricated on a FR4 substrate having size of 0.08 λ_G x 0.14 λ_G, with λ_G as the wavelength at the first resonant frequency. The MW-BPF achieves the following transmission coefficients/ fractional bandwidth of-0.84 dB / 42.5 %,-1.36 dB / 21.49 %,-1.85 dB / 14.95 %,-2.12 dB / 10.69 %, and-2.11 dB / 6.02%, at 0.44 GHz, 0.88 GHz, 1.30 GHz, 1.77 GHz, and 2.15 GHz, respectively. This filter can be applied to DVB-T400, GSM800/GSM900, GPS1200, WCDMA1800, and LTE2100. The validity of the proposed design has been shown by the good agreement between the simulation and measurement results.