A compact wideband coupler design for 5G applications

Abstract This paper introduces the design of a compact, broadband coupler tailored for 5G applications. The proposed innovative approach deftly combines two distinct techniques: stepped impedance structures and meandering paths. This integration aims not only to miniaturize the coupler and expand its bandwidth but also to uphold exceptional performance, particularly within the core 3.5 GHz frequency band. The method achieves a notable 59% reduction in size compared to conventional designs and realizes an impressive fractional bandwidth of 40%. These attributes make the design particularly suitable for 5G systems, which demand both compact structures and wide bandwidths to support dense signal environments and high data throughput. By uniting these techniques in a single design, this work achieves both significant size reduction and enhanced bandwidth within a streamlined structure, setting it apart from previous studies. Additionally, the coupler maintains a precise quadrature phase difference between its output ports. Extensive experimental results affirm the effectiveness of this innovative approach, highlighting its potential for designing compact, high-performance couplers suited to advanced 5G applications.