Multi-Wideband Band Pass Filter Using Quad Cross-Stub Stepped Impedance Resonator

Abstract

This simulation study involved the use of a QC-SSIR (quad cross-tub stepped impedance resonator) to examine the behavior and performance of the MW-BPF (multi-wideband band pass filter). To evaluate the performance of the proposed model, it was compared to the case of the conventional resonator. In the results, MW-BPF was found o exhibit a superior performance in terms of the ease of fabrication, good transmission coefficients, and a wider fractional bandwidth. For the filter structure analysis, this study incorporated the ABCD matrix, with the design of the MW-BPF also based on the FR4 microstrip. The experimental conditions and parameters were set in such a way that for the substrate, tan δ = 0.0265, thickness = 1.6 mm, and εr = 4.4, and thickness h = 1.6 mm. at 2.58 GHz, 1.71 GHz, and 0.81 GHz, the proposed QC-SSIR-based MW-BPF achieved transmission coefficients/fractional bandwidths of 1.93 dB/13.9%, 1.49 dB/18.7%, and 0.60 dB/49.3%, respectively. Relative to the filter size reduction, the FQC-SSIR (folded quad cross-tub impedance resonator) was incorporated. The resultant observations indicated a possibility of BPF size reduction up to 46%. Also, the proposed framework was found to yield (at 2.62, 1.80, and 0.82 GHz) 1.76 dB/12.5%, 1.21 dB/17.7%, and 0.57 dB/49.6% transmission coefficient/fractional bandwidths, respectively. It is also worth indicating that the filter employed LTE2600, WCDMA1800, and GSM800. Therefore, the model exhibited a good agreement, which was depicted by the comparison outcomes between the measured values and the simulated values. Hence, the proposed design was found to be valid and reliable.