A thermally stable dual-polarized waveguide array

This paper presents simulated and measured results for a dual polarized slotted waveguide antenna panel in C-band. Dual polarization is achieved by interleaving ridge waveguides with rectangular waveguides standing on the narrow side, using each type of waveguide for the corresponding linear polarization. The complete arrangement is fitted within the same footprint as a single polarized array of waveguides with classical broad wall slots. By exciting the radiating waveguides from barline networks, an improvement in thermal stability and more freedom in the selection of excitation coefficients are achieved compared to the classical solution with a coupling waveguide on the rear side of the radiating waveguides. The antenna panel has been designed using two major tools: An inhouse waveguide antenna design tool with heritage from the design of the ERS and ASCAT antennas in combination with simulations in Ansys HFSSTM. It is worth noting that the design was successful and the results consistent in all steps: The radiation pattern from the initial optimizations based on element patterns for the slots has an excellent agreement to the measured pattern of the final manufactured panel. No extensive breadboarding or design iterations have been necessary. The main application for the presented panel is to be used as part of a satellite based wind scatterometer instrument on MetOp Second Generation (MetOp-SG) but it is also a candidate for other applications involving thermally stable dual polarized antennas with good power handling capability.