Compact multilayered three-channel multiplexer using synthesized microstrip lines and striplines

A compact multilayered three-channel multiplexer is investigated in this paper. The multiplexer is developed by integration of ten synthesized microstrip lines and striplines. It has three transmission passbands at 0.9, 1.8, and 2.4 GHz. Open-circuited stubs are utilized as wave trapping circuits to provide port isolation. A new idea for synthesizing high-impedance artificial line is discussed. The proposed multiplexer shows a compact size of 14.5 × 12.5 mm
²
. The circuit configuration and simulated and experimental results are discussed.