Low-Cost and High-Q Millimeter-Wave Resonator Using Substrate Integrated Waveguide Technique

A substrate integrated waveguide (SIW) cavity directly coupled to a planar circuit, i.e. microstrip line or coplanar waveguide, is presented. Different coupling topologies and coupling probes are discussed. Empirical equations to predict the resonance frequencies of the cavity are provided. A temperature stability coupling topology were fabricated and measured. Finally, as an example of potential applications, a filter using two SIW cavities was designed and measured.