Wideband Substrate Integrated Waveguide Chip Filter Using Spoof Surface Plasmon Polariton

• Published in: Micromachines (Basel) Vol. 13; no. 8; p. 1195
• Main Authors: Pan, Dongzhe, You, Bin, Wen, Xuan, Li, Xungen
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 28.07.2022; MDPI
• Subjects: Acoustics; Bandpass filters; Broadband; Capacitors; Cross coupling; Design; Design and construction; Electric filters, Bandpass; Installation; integrated passive device; Plasmons (Physics); Polaritons; Propagation; Sidebands; spoof surface plasmon polaritons (SSPPs); substrate integrated waveguide (SIW); Substrate integrated waveguides; through-dielectric capacitor (TDC); Trends; Waveguides; China
• ISSN: 2072-666X; 2072-666X
• DOI: 10.3390/mi13081195

This article presents a novel wideband bandpass filter based on the integration of a substrate integrated waveguide (SIW) and a spoof surface plasmon polariton (SSPP). An SIW cavity with periodic arrays of meander-slot units is etched on the top metallic layer to achieve the characteristics of a multi-order filter with good performance. The passbands can be flexibly selected by varying the geometric parameters of the SIW and SSPP to adjust the lower and upper sidebands independently. Using a redistribution layer (RDL) process, a novel 3D capacitive interconnection called a through-dielectric capacitor (TDC) is proposed and collaboratively designed with an interdigital capacitor to achieve capacitive source-load cross-coupling. The proposed filter has a center frequency of 60 GHz, with a wide 3-dB fractional bandwidth of about 45.8%. The improved simulated sideband suppression has a 30 dB rejection at 40 GHz and 75.4 GHz, corresponding to a 30-dB rectangular coefficient of 1.28.