Fullwave analysis of non-contacting rotary joint choke sections using the generalised scattering matrix (GSM) approach

An accurate fullwave analysis of waveguide (WG) rotary joint non-contacting choke sections is presented. The generalised scattering matrix (GSM) approach is used, with the constituent matrices having been obtained through a mode-matching formulation for a general waveguide bifurcation, a coaxial-to-coaxial WG junction, and a circular-to-circular WG junction. This approach is ideally suited to geometries where there are small gaps whose precise dimensions are critical for proper component operation. A detailed analysis of these components, using modern numerical modelling, does not appear to have previously been published.