Design and Analysis of Dual-Mode Double-Square Loop Resonator for Bandpass Filter Applications

The paper presents a double-square loop (DSL) resonator for a dual-mode bandpass filter; the resonator has two sides of unequal length. We use the IE3D electromagnetic simulation software for evaluating the effects of the DSL-type bandpass filter and an FR4 substrate for comparing the differences between the simulated and the measured results. The center frequency of the filter is set to be around 2.4 GHz in both the simulation and the implementation. The simulated and the measured results reveal that the filter frequency and bandwidth are very similar in both cases and prove that the microstrip-line bandpass filter can be used as a passive component in a variety of applications in the field of communications.