Analysis procedure for arrays of waveguide slot doublets based on the full T-network equivalent circuit representation of radiators

An array of longitudinal slot doublets in a rectangular waveguide may be modelled by an equivalent single-slot array in a halfheight waveguide. The slot electric fields display an increasing degree of asymmetry with large slot offsets and a reduction in waveguide height. In such cases, the values of the series elements in the equivalent T-network representation of radiators become significant. Existing analysis techniques ignore their effects and use a simple shunt element equivalent circuit model. The paper presents an offcentre-frequency analysis procedure for slot arrays which is based on the full T-network model for individual radiating elements. Calculations display excellent agreement with measured and fullwave analysis results for the scattering parameters of a slot doublet array.