A novel compact diplexer employing substrate integrated waveguide loaded by triangular slots for C-band application

Abstract

This article presents a novel design of compact Substrate Integrated Waveguide (SIW) filters loaded with a triangular slot. First, the filtering response is obtained by loading a triangular slot on the top of the SIW cavities. Later, these SIW filter structures are cascaded to develop a SIW planar diplexer. To achieve lower and upper channels of the diplexer, two SIW cavity-backed filters loaded with triangular slots are excited with in-line feedings. To demonstrate the analysis, the proposed SIW diplexer has been simulated, fabricated, and tested. The measured S-parameters are in good agreement with the simulated results, showing the lower and upper passband insertion losses based at 6.2 GHz and 7.75 GHz are obtained as 0.87 dB and 0.75 dB including the losses from both the SMA connectors, respectively. The fractional bandwidth (FBW) is more than 5.1% at each passband with high isolation better than 22 dB. The fabricated prototype has a compact size of 0.88 (${\lambda }_g^2$).

Keywords:

• SIW
• triangular slot
• bandpass filter
• diplexer

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work is partially supported by the National Institute of Technology, Tiruchirappalli seed grant [NTT/R&C/SEEDGRANT/19-20/P.09/ECE/SSK] and IMPRINT-II under grant [IMP/2018/001932]. In part by the National Natural Science Foundation of China under Grant [62071211]; and in part by the University Key Research Project of Guangdong Province under Grant [2018KZDXM063].

Notes on contributors

N. C. Pradhan

Nrusingha Charan Pradhan received the B.Tech. degree from Biju Patnaik University of Technology, India, in 2013, and the M.Tech degree in electronics engineering from Pondicherry Central University, Puducherry, India, in 2016. He was with the Integrated Test Range, Defence Research and Development Organisation, Chandipur, India (ITR-DRDO) for a period of two year. He is currently a Research Scholar with the Department of Electronics and Communication Engineering, National Institute of Technology, Tiruchirappalli, India. He has 18 technical papers. His current research interests include microwave integrated circuits, Substrate Integrated Wave Guide Components for Millimeter Wave Applications. Mr. Pradhan is a Student Member of the IEEE AP Society, the MTT Society. He is a Student branch Chair of the IEEE-MTTs Society NIT, Trichy. He is a IEEEXtreme ambassador 15.0 at IEEEXtreme.

S. S. Karthikeyan

Karthikeyan Sholampettai Subramanian received the Ph.D. degree from IIT Guwahati, India, in 2011. He has 13 years of educational activity and research experience in the area of RF and microwave. He was the Short-Term academic foreign visit U.K and France. He is currently Assistant Professor with the Department of Electronics and Communication Engineering, National Institute of Technology, Tiruchirappalli, India. He has authored or co-authored more than 100 scientific research papers and technical reports. His current research interests include microwave integrated circuits, biological effects of microwaves, computer-aided design of MICS, metamaterials/frequency selective surfaces (FSSs), fractal antennas, MIC antennas, metamaterial antennas, and substrate-integrated waveguides. He is a member of the IEEE, IEEE MTT-S, and IEEE AP-S. He is a Life Member of the ISTE.

R. K. Barik

Rusan Kumar Barik received the B.Tech degree in Electronic & Communication Engineering from Biju Patnaik University of Technology, Rourkela, India in 2012, M.Tech degree in Communication Systems Design and Ph.D. degree in Electronics Engineering from Indian Institute of Information Technology, Chennai, Tamil Nadu, India, in 2015 and 2018, respectively. He joined the Department of Electronic & Communication Engineering, Christ University Bangalore, India, as an assistant professor in 2018. He is currently a Post-Doctoral Researcher with the Engineering Optimization and Modeling Center, Department of Engineering, Reykjavik University, 102 Reykjavik, Iceland. His research interests include multiband microwave passive devices, multiband antennas, and SIW components.

Q. S. Cheng

Qingsha S. Cheng received the B.Eng. and M.Eng. degrees from Chongqing University, Chongqing, China, in 1995 and 1998, respectively, and the Ph.D. degree from McMaster University, Hamilton, ON, Canada, in 2004. In 1998, he joined the Department of Computer Science and Technology, Peking University, Beijing, China. In 1999, he joined the Department of Electrical and Computer Engineering, McMaster University, where he worked as a postdoctoral fellow, a research associate, and a research engineer. He is currently an Assistant Professor with the Department of Electrical and Electric Engineering, Southern University of Science and Technology, Shenzhen, China. His research interests include surrogate modeling, CAD, modeling of microwave circuits, software design technology, and methodologies for microwave CAD.