Compact Band-Pass Filter Using Modified Ω-shaped Resonator and Source Load Coupling for Transmission Zero Improvement

Abstract

This article investigates a compact band-pass filter using modified Ω-shaped resonator and source load coupling for transmission zero improvement. In this article, source load coupling has been used to improve the insertion loss response and a number of transmission zeros in the upper stop-band, so that the chance of interference from adjacent wireless bands can be reduced. In order to determine the metamaterial characteristics for the designed filter structure dispersion diagram and vectored electric-field with no phase variation has been illustrated. The simulated and measured 3dB fractional bandwidth for the designed filter structure is 26.05% and 26.12% at the center frequency of 2.38 and 2.33 GHz respectively. It offers compactness with an electrical footprint area of 0.245λg × 0.201λg, where λg is the guided wavelength at the center frequency of 2.33 GHz. The presented filter structure seems a potential candidate for different wireless applications such as Bluetooth (2.4-2.48 GHz), WLAN/Wi-Fi (2.4-2.49 GHz) and Wi-MAX (2.5-2.69 GHz).