Design of L1/L2 GPS BPF Using Closed-Loop Rectangular Ring Resonator

Abstract

In this paper, a new compact dual-band filter based on closed-loop rectangular ring resonator is presented. Two passbands are designed to operate at L1 and L2 global positioning system (GPS) bands, respectively. The first passband is established by utilizing the dimension of square ring resonator that resonates at L1 band. Then, a perturbation mode element is applied to the upper and lower sides of the ring to separate the other degenerate mode and allocate the second passband of the filter at L2 GPS band. The dual passband can be adjusted to meet the designer requirements. The frequency selectivity of the filter is improved by using two symmetric parallel-coupled 0-degree feed structure that introduce a pair of transmission zeros around the passband. A practical dual-band bandpass filter is fabricated and measured. The measured results show good agreement with the simulated ones.

Keywords:

• Bandpass filter
• Dual-Mode
• Even-odd mode theory
• GPS
• Microstrip filters
• Square ring resonator

Additional information

Notes on contributors

Emad Shehab Ahmed

Emad Shehab Ahmed was born in Mosul, Iraq, in 1960. He received the BSc degree in electrical engineering from Mosul University, Mosul, Iraq, in 1982, the MSc degree and PhD degree in communication engineering from M College of Engineering, Baghdad—Iraq in 1990 and 2002, respectively. He is currently an assistant professor of communication engineering at University of Technology, Baghdad—Iraq. His research interests include microwave circuits design, antennas and wave propagation.