Advances in planar coaxial SIW resonator filters design

In the chapter it has been demonstrated that the application of a coaxial topology to the SIW was able to boost considerably the properties of this promising technology, since it enables for an important size reduction preserving an overall good EM performance. The latter has been demonstrated where the in-depth analysis of the coaxial SIW performance helped to understand the resonant nature of the structure, resulting in a conclusive equivalent circuit composed by a substrate-integrated coaxial line loaded by a capacitor. The proposed topology showed a wide variety of configurations, which were represented by the variations of the resonator slope parameter, enabling designers to adapt easily the resonator properties for satisfying different requirements.