A Compact Filtering Power Divider Based on Spoof Surface Plasmon Polaritons and Substrate Integrated Waveguide

• Published in: IEEE microwave and wireless components letters Vol. 32; no. 2; pp. 101 - 104
• Main Authors: Pan, Bai Cao, Yu, Ping, Liao, Zhen, Zhu, Fang, Luo, Guo Qing
• Format: Journal Article
• Language: English
• Published: IEEE 01.02.2022
• Subjects: Bandwidth; Compact design; filtering power divider; Power dividers; Resistors; Scattering parameters; spoof surface plasmon polaritons (SSPPs); Substrates; Surface plasmon polaritons; Wireless communication
• ISSN: 1531-1309; 1558-1764
• DOI: 10.1109/LMWC.2021.3116169

In this letter, a compact bandpass filtering power divider with tunable bandwidth based on spoof surface plasmon polaritons (SSPPs) and substrate integrated waveguide (SIW) is proposed. The hybrid-SIW-SSPP structure shows good potential to expand the scope of bandwidth control of the device. The bandwidth can be designed in a wide range by simply optimizing its dimensions or loading interdigital structures (ISs). Defected ground structure (DGS) is also introduced on the bottom layer to further improve the out-of-band suppression. And good isolation can be obtained via additional resistors welded across the SSPP slot. A prototype loaded with dumbbell-shape DGS and two resistors is fabricated with an overall size of 45 mm <inline-formula> <tex-math notation="LaTeX">\times18 </tex-math></inline-formula> mm <inline-formula> <tex-math notation="LaTeX">\times0.5 </tex-math></inline-formula> mm. Both <inline-formula> <tex-math notation="LaTeX">S_{21} </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">S_{31} </tex-math></inline-formula> are around −3.8 dB within the whole <inline-formula> <tex-math notation="LaTeX">X </tex-math></inline-formula>-band. The simulated and measured results agree with each other well.