In this paper, a compact tri-band microstrip filter is designed and fabricated for application in wireless communication systems such as Bluetooth, WIMAX (World Wide Interoperability for Microwave Access), and WLAN (Wireless Local Area Network). In the proposed filter, three resonators, i.e., Stub-Loaded Resonator (SLR), Stepped-Impedance Resonator (SIR), and Square Split Ring Resonator (SSRR), are used. The dimensions of the proposed filter are equal to 16.2×12.3 mm2 or 0.219λg×0.166λg. These dimensions indicate that the proposed structure has reduced the size by about 40% compared to the conventional samples. This is the main advantage of the proposed filter. Finally, in order to investigate analysis and simulations, the proposed filter is fabricated. The results prove correctness of the design, analysis, and simulations.
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