Dual-band Multi-Polarization Metallic Cavity Antenna Design for Satellite Communications

A highly reconfigurable dual band cavity structure for satellite communications at K/Ka band is proposed. The key of the presented structure lies on a compact dual stacked cavity system. By modifying the radius of each cavity and the dimensions of the feeding slot, both cavities have been matched at the center frequency of their respective band. Correctly enabling and phasing each input port allows to generate any desired polarization scheme. Cavity radius were carefully chosen to prevent any coupling of the K band cavity with the Ka band one. For demonstration purposes, this structure has been integrated with a Turrin horn antenna that operates as a multimode horn for the Ka band. Monomode operation at the lower band was ensured by limiting the horn aperture radius. In this configuration a directivity of 10.3/12.4dB in K/Ka band was achieved.