Effect of transition waveguides on dielectric waveguide directional couplers

• Published in: IEEE transactions on microwave theory and techniques Vol. 37; no. 4; pp. 686 - 690
• Main Authors: Shanjio Xu, Peng, S.T., Schwering, F.K.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.04.1989; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Approximation methods; Circuit properties; Coupling circuits; Dielectric losses; Directional couplers; Electric, optical and optoelectronic circuits; Electronics; Exact sciences and technology; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Performance loss; Scattering; Waveguide components; Waveguide junctions; Waveguide theory; Waveguide transitions; Directional coupler; Dielectric charge; Mode coupling; Microwave coupler; Analysis method; Waveguide junction; Bent waveguide; Waveguide
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/22.18840

The coupling of energy between two curved dielectric waveguides is investigated by the staircase approximation method, which combines the building-block approach of multimode network theory with a rigorous mode-matching procedure. Particular attention is directed toward two major effects of transition waveguides on the performance of directional couplers composed of dielectric waveguides: one is the change in the coupling length, the other is the radiation loss. The coupling problem is analyzed in terms of the scattering of an incident guided mode by the coupler structure as a whole. Numerical results are given to illustrate the coupling characteristics of various structures and to establish useful guidelines for the design of directional couplers.< >