Compact Low-Loss Selective Coupler (CLSC) Concept for Insertion Loss, Mutual Coupling and Size Miniaturization

This paper presents a new class of feeding network which exhibits compact, low-loss, high isolation. By using multiple stub lines, compact, low-loss, selective coupler (CLSC) is implemented. The proposed CLSC demonstrates a transmission coefficient of over -1.5 dB and an isolation value of over -30 dB across a frequency band spanning from 24 GHz to 50 GHz for demonstration purposes. This study enables miniaturization of the insertion loss, mutual coupling, and overall dimension of the entire feeding network structure and can be applicable to various microwave and millimeter-wave (mmWave) applications.