Band-stop filter design based on split ring resonators loaded on the microstrip transmission line for GSM-900 and 2.4 GHz ISM band

Abstract

Split-ring resonator is a popular research topic in literature. As known, it may be used in the design of electromagnetic metamaterials. Additionally, these structures can be preferred in microwave filter devices. In this study, a band-stop filter was designed for GSM-900 and 2.4 GHz ISM band by using split-ring resonators. Two split-ring arrays (sizes of one of these arrays were larger than the other) were loaded on the transmission line and each array consisted of four identical rings. Thus, a dual-band pass filter was obtained and this filter covered the frequency of 0.91 (GSM) and 2.43 (ISM) GHz. Then, this proposed design was fabricated and measured. According to the measurement results, the fabricated structure operated at 0.93 GHz and 2.47. The experimental results were consistent with the simulation results. As a result, thanks to the proposed structure, two frequencies can be stopped at the same time. There is no need to design a different filter structure for each frequency.