Small Dual Narrowband BPF with Ultra-Rejection Band Using Grounded Stepped-Impedance Resonator

Abstract

A simple technique, to design a dual narrowband bandpass filter with wide stopband performance, is introduced in this article based on a grounded stepped-impedance resonator (GSIR). The GSIR is a multi-behavior resonator. Following the even–odd analysis, the proposed GSIR is first analyzed to generate the specified center frequencies of the proposed passbands. Next, two ring-shaped stubs are electrically coupled to the low impedance part of the GSIR, using coupling space (s) and direct connection to the input/output ports to determine the filtering response. Finally, an experimental filter for 2.4 GHz wireless local area network and 3.5 GHz worldwide interoperability for microwave access (WiMAX) applications is constructed. The filtering characteristic performances of the simulation and measurement results are compared and discussed. Consequently, two narrow bandwidths, 40 MHZ at 2.4 GHz and 60 MHz at 3.5 GHz, are generated with ultra-high frequency suppression above 20 GHz. The surface area of the designed filter is about 56 mm² terminating the feeding ports.

Keywords:

• Dual-band BPF
• Multi-behavior resonator
• Narrowband BPF
• Small bandpass filter
• Stepped-impedance resonator

Additional information

Notes on contributors

Raaed T. Hammed

Raaed T Hammed received his BSc in electrical and electronic engineering and MSc in electronic engineering from the University of Technology/Baghdad, Iraq in 1996 and 2002, respectively, the PhD in electronic/microwave engineering from the University of Essex/Colchester, UK in 2012. For the last four months in 2012, he was a researcher in the University of Essex. Now, he is currently an assistant professor in the University of Technology. He has professional expertise in the microstrip circuit fabrication process. His research interest includes microwave passive and active circuits such as filters, balun circuit, power amplifier, etc.

Saad M. Abbas

Saad M Abbas was born in 1961 at Baghdad, Iraq. He received BSc and MSc degrees in 1984 and 1986, respectively from the University of Belgrade, Serbia. In 2014, he received his PhD degree from the National University of Malaysia (UKM). Since 2005 he has been an assist professor at the Department of Electrical Engineering, the University of Technology, Iraq. His field of interest includes microelectronics, designing implantable micro-system stimulator, bio-medical implantable devices and inductive coupling links for bio-medical applications. He has published more than 40 published papers in international scientific journals. He is the Editor board Member and a reviewer in several journals. He is an IEEE Member. Email: [email protected]