Stepped Impedance Resonator (SIR) bandpass filter on metamaterial substrate / Mohd Rosdi Abu Bakar

Bandpass filter is a very popular filter used in mobile and radio wireless communication. Recent development of wireless communication system demand an efficient bandpass filter to select the required signal from the adjacent signals. This paper presents a Stepped Impedance Resonator (SIR) Bandpass filter (BPF) incorporated with Defected Ground Structure (DGS) for Wimax application. The arrowhead DGS was introduced in the design to obtain metamaterial characteristics with negative values of permittivity (£r) and permeability (u). The advantage of metamaterial is reducing the size of the filter without effecting the performance of the device that resonates at 3.5GHz. Two filters were designed and simulated: conventional and metamaterial SIR BPF using Computer Simulation Technology (CST) and Genesys Software. Both filters were fabricated on a same substrate, Rogers RO3003 with permittivity, Sr = 3.0 and thickness, h = 0.5mm. The measurement of the fabricated filters was done using Vector Network Analyzer (VNA). The metamaterial filter shows 25.29% smaller in size compared to the conventional and it is also improves the return loss by 29.04%. It was proven that the DGS approach in designing the filter can reduce the size of the device.