Novel compact microstrip dual‐mode multistub‐loaded stepped‐impedance resonator and application to communication systems

Abstract

In this article, a novel compact microstrip dual-mode multistub-loaded stepped-impedance resonator is introduced. Steppedimpedance resonator can be used for achieving the fundamental resonance frequency; however, the size of this structure is not compact and resonance frequencies are dependent. Utilizing multistubs as loaded elements improves size miniaturization with low permittivity substrate and brings the advantage of flexible controlling of one resonance frequency whereas the other one is fixed. As an application, a dual-band bandpass filter is presented to operate at 3.5 and 5.2 GHz, corresponding to the worldwide interoperability for microwave access and wireless local area network applications. An overall good agreement between the measured and simulated results is observed, confirming the proposed method.