Substrate Integrated Waveguide SPST Switch with Single SMD PIN Diode

A substrate integrated waveguide (SIW) switch is presented in this paper. The switch is based on a modified SIW choke (MSC) structure loaded at the coplanar waveguide (CPW) port by a single, SMD packaged PIN diode. The switch covers two or more narrow frequency bands, depending on electrical length of the MSC, while the length over the main signal paths equals the coupling slot width, of about 1 mm. Thin dielectric sheets assembled between the SIW structures have a slight effect on switch's characteristics, and hence the SIW parts can be completely isolated from each other.