A portable cradle for carrying a PAP device includes a base and a handle that is provided on the base. In an embodiment, the isolation module includes a step-up autotransformer comprising a first and second winding that are electrically coupled in series at a center node. The housing has an inlet and an outlet fluidly communicating with the internal cavity. The first dielectric layer stacked on the waveguide. The inner sleeve is fixedly attached to one of the outer sleeve and the outer tubular member.