3 dB 90 ^ Hybrid Quasi-Optical Coupler With Air Field Slab in SIW Technology

• Published in: IEEE microwave and wireless components letters 2014-04, Vol.24 (4), p.221-223
• Main Authors: Djerafi, T., Wu, K., Tatu, S. O.
• Format: Article
• Language: English
• Subjects: Applied sciences; Circuit properties; Couplings; Design. Technologies. Operation analysis. Testing; Dielectric constant; Directional coupler; Directional couplers; Electric, optical and optoelectronic circuits; Electronic equipment and fabrication. Passive components, printed wiring boards, connectics; Electronics; Exact sciences and technology; Frequency ranges; Integrated circuits; Joining; Loss measurement; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Microwaves; millimeter-wave integrated circuits; Noise levels; Permittivity; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Slabs; substrate integrated waveguide (SIW); Substrates; Waveguides
• ISSN: 1531-1309; 2771-957X; 1558-1764; 2771-9588
• DOI: 10.1109/LMWC.2013.2295297

This letter presents a new class of small-size and high performance directional coupler based on substrate integrated waveguide (SIW) technology. This type of coupler is composed of a waveguide section of four arms connected by a central junction. Quasi-optical coupler technique is realized on standard waveguide by simply inserting a slab with different permittivity in central section to act as a mirror. To make this coupler realizable in the SIW format, the air slab is simply implemented by rectangular through-hole. Characteristics of the proposed coupler with respect to various parameters are presented and discussed. A prototype at 10 GHz is designed, fabricated and measured. Experimental results show that the proposed SIW cruciform coupler has a bandwidth of more than 15% over the operating frequency range.