Contoured-beam reflectarray for DBS application including copolar isolation requirements between missions

A reflectarray antenna designed to fulfil both coverage and isolation requirements of a commercial DBS mission with South American coverage (PAN-S) is presented. The PAN-S mission includes requirements for the coverage footprint and isolation with an European coverage (EUR). Both requirements have been used in the design process of a 1.2 m reflectarray. In order to synthesize the radiation pattern, a phase-only algorithm based on the intersection approach technique is used. The isolation requirements are introduced by a suitable definition of the coverage areas and associated templates for maximum and minimum gain. As a result of the pattern synthesis, not only the compulsory isolation with EUR mission is achieved, but also isolation with North America coverage (PAN-N) can be significantly improved. After the pattern synthesis, a reflectarray made of 3 layers of varying-sized patches was designed, by optimising the dimensions of the patches to match the phase obtained from the synthesis for dual-linear polarisation at several frequencies in Tx (11.7-12.2 GHz) and Rx (13.75-14.25 GHz) bands. The results show that the coverage requirements are always fulfilled in more than 90% of the surface in each zone for TX and RX bands.