A compact dual-band patch coupler design for modern wireless applications

Abstract

This paper presents a compact rectangular patch hybrid coupler design which can be operated at dual resonant frequencies and is suitable for modern wireless applications. The dual-band functionality while maintaining practical compactness is achieved by introducing a series of parallel rectangular slots. The proposed design is optimized by the CST studio suite software and etched on the FR4 substrate. The good agreement between the simulated and measured frequency responses indicate that the presented coupler is capable of operating from 2.44 GHz to 3.1 GHz and from 5 GHz to 5.8 GHz, with fractional bandwidth of 24.44% and 14.8%, respectively, and a size reduction of 56.28%. The robust simulation results indicate that the proposed design is suitable for microwave integrated circuits (ICs) that require small size and dual functionality.