Slow-Wave Substrate Integrated Waveguide

• Published in: IEEE transactions on microwave theory and techniques Vol. 62; no. 8; pp. 1625 - 1633
• Main Authors: Niembro-Martin, Alejandro, Nasserddine, Victoria, Pistono, Emmanuel, Issa, Hamza, Franc, Anne-Laure, Vuong, Tan-Phu, Ferrari, Philippe
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.08.2014; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Circuit properties; Cutoff frequency; Design. Technologies. Operation analysis. Testing; Electric, optical and optoelectronic circuits; Electromagnetism; Electronic tubes, masers; Electronics; Engineering Sciences; Exact sciences and technology; Integrated circuits; Magnetic fields; Magnetic noise; Metals; Micro and nanotechnologies; Microelectronics; Microstrip; Microstrip transmission lines; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Microwaves; Phase velocity; Planes; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Simulation; Slow-wave effect; Solid modeling; substrate integrated waveguide (SIW); Substrates; Topology; transition from microstrip to slow-wave SIW (SW-SIW); Waveguides; Electromagnetism; Multilayer coating; Return loss; Substrate integration; Travelling wave tube; Waveguide; Cut off frequency; Microstrip line; Phase velocity; Electric field; Transmission line; transition from microstrip to slow-wave SIW (SW-SIW); Simulation; Interconnection; substrate integrated waveguide (SIW); Integrated circuit; Slow-wave effect; Slow wave structure; Magnetic field; Double layers; Via hole
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2014.2328974

This paper describes a new concept of substrate integrated waveguide (SIW): a slow-wave substrate integrated waveguide (SW-SIW). Compared to a conventional SIW, the proposed topology requires a double-layer substrate with a bottom layer including internal metallized via-holes connected to the bottom conductive plane. The slow-wave effect is obtained by the physical separation of electric and magnetic fields in the structure. Electromagnetic simulations show that this topology of SIW allows decreasing the longitudinal dimension by more than 40% since the phase velocity is significantly smaller than that of a classical SIW. Simultaneously, the lateral dimension of the waveguide is also reduced. By considering a double-layer technology, SW-SIWs exhibiting a cutoff frequency of 9.3 GHz were designed, fabricated, and measured. The transversal dimension and the phase velocity of the proposed SW-SIW are both reduced by 40% as compared to a classical SIW designed for the same cutoff frequency, leading to a significant surface reduction. Moreover, an original kind of taper is proposed to achieve a good return loss when the SW-SIW is fed by a microstrip transmission line.