A Compact Diplexer Using Coupled π-CRLH Zeroth Resonators

ABSTRACT

This paper presents a new diplexer design of a new-coupled composite right/left-handed (CRLH) resonator to serve the LTE applications. The realization of the diplexer is designed as coupled two zeroth order π-CRLH resonators to represent with zero electrical length and hence attaining a significant size reduction. The filters are designed to achieve a desired frequency bandwidth of 4% ∼16.7 Q-factor and ∼0.066 coupling coefficient at a centre frequency of 2.1 and 2.6 GHz with transmission zeros. The diplexer exhibits a rejection level of 15–20 dB while maintaining insertion loss of 1 dB for the Tx and Rx bands. The circuit design concepts are verified using equivalent circuit simulations, full electromagnetic simulations and experimental measurements. In conclusion, a good agreement is perceived between the measured and simulated data with size compactness of 30 × 60 mm².

KEYWORDS:

• Composite right/left-handed (CRLH)
• Metamaterial
• Diplexer
• Zeroth-order resonance

Additional information

Notes on contributors

Ashraf Y. Hassan

Ashraf Y Hassan was born in Bonn, Germany. Received the BSc in electronical communication and electronic systems from the Engineering Department of MSA University, Giza, Egypt in 2015. With grade of excellent in graduation project with publication in the field of microwave engineering. He received his MSc degree in wireless mobile communication systems, focused on metamaterial applications in microwave components from University of Greenwich, UK, 2016. Email: [email protected]

Mohamed F. Hagag

Mohamed F Hagag (S’12–M’18) received the BS and MS degrees in electrical and computer engineering from the Military Technical College, Cairo, Egypt, in 2007 and 2013, respectively, and the PhD degree in electrical and computer engineering from Purdue University, West Lafayette, IN, USA, in 2018. From 2009 to 2014, he was a research and teaching assistant with the Electronic Engineering Department, Military Technical College. From 2015 to 2018, he was with the School of Electrical and Computer Engineering and Birck Nanotechnology Center, Purdue University, where he was involved in reconfigurable RF front-end components based on high-Q cavity resonators. Dr. Hagag was a recipient of the Best Conference Paper Award of the IEEE 19th Wireless and Microwave Technology Conference (WAMICON), Clearwater, FL, USA, in 2018 and the Third Place Award of the RF Tunable Filter Student Design Competition of the 2018 IEEE MTT-S International Microwave Symposiums. Email: [email protected]

Ahmed A. Abdel Aziz

Ahmed A Abdel Aziz received the BSc from Avionics Department (with honours), Military Technical College, Cairo, Egypt in 2014. He joined the Avionics Research Centre from 2014 with main concern about RF and metamaterial-based components. He received the MSc degree in graphene and metamaterial structures for microwave applications from the Electrical Engineering Department, Military Technical College, Cairo, Egypt in 2019. Mr Ahmed’s main focus is microwave components, so he is interested in metamaterials, metasurface, and wearable components. Email: [email protected]

Mahmoud A. Abdalla

Mahmoud A Abdalla was born in 1973. He received the BSc degree, with grade of excellent with honours, in electrical engineering from the Electrical Engineering Department, Military Technical College, Cairo, Egypt in 1995. He was awarded the MSc degree in electrical engineering from Military Technical college in 2000, and the PhD degree from microwave and communication group, School of Electrical Engineering, Manchester University, UK, in 2009. He has been with Military Technical College since 1996 where he is now a professor, the head of the Council Committee and the electromagnetic waves / microwave group in Electronic Engineering Department. Also, he has been a visiting professor in Department of Computer and Electrical Engineering, University of Waterloo, Canada since 2017. His research has focused on different metamaterial applications in microwave and millimeter bands specially microwave components, miniaturized multiband antennas and ferrite components, electromagnetic energy harvesting systems, EBG components and radar absorber. He has published more than 200 peer-reviewed journal and conference papers. Dr Abdalla is currently an IEEE senior member, URSI senior member and a member of the IEEE and the European Microwave Association EuMA. He is an editor member and reviewer in many electromagnetic journals such as IEEE Antennas and Wireless Propagation Letters, IET Microwaves antenna and propagation, and others. Dr. Mahmoud was the recipient of Egyptian encouragement state prize award for engineering sciences in 2014. In 2019, he was the recipient of Egyptian El-Sherouq innovation award in electronic engineering. Also, he was awarded the top 1% Publon worldwide reviewer award for 2018 and 2019. In 2020, he was named in the top 2% scientists in “A standardized citation metrics author database annotated for scientific field / “Updated science-wide author databases of standardized citation indicators”.