A Novel Four-Port Directional Structure with Strongly Coupled Transmission Lines Based on Microwave hybrid Integrated Circuits

摘要

Analysis is performed and principles are formulated of optimal strong coupling of microstrip transmission lines. A novel multilayer structure with strong coupling is proposed for implementing ultrawideband 3-dB directional couplers (DCs) based on microwave hybrid integrated circuits (HICs) and devices employing them. Specific features of this structure are considered, and characteristic parameters are studied theoretically. Experimental results are presented.