Metam aterial-based planar waveguide filters and components for light-weight multi-channel vehicular transceivers

In this paper, it is presented that novel and compact filters and channel combiners are developed for a lighter multi-channel vehicular transceiver working at an X-band and a Ku-band as high frequencies instead of bulky metallic waveguides. The components are in the form of so-called substrate integrated waveguide(SIW) as planar layered structures. For the purpose of reducing the physical sizes of the aforementioned components further from the conventional SIWs for the frequency bands near the millimeter-wave region, the internal parts of the proposed SIWs play the components of the CRLH-line as a metamaterial structure, which turns out much smaller than the SIWs of the same frequency. This is indebted to the phase-lead effect from the LH zone. Firstly, the compact SIW filters are implemented for the channels, particularly, an X-band and a Ku-band in this case, but applicable to millimeter-wave bands, if needed. Secondly, they are combined in another SIW to keep the two channels least distorted as a compact duplexer. The frequency responses of the filters and the channel combiner are given with the photographs of the fabricated versions. The size-reduction effect by the proposed method is mentioned with the conventional waveguide counterparts. It is easy to predict that the design scheme can be adopted for light-weight and low-profile vehicular transceivers.