This paper presents a comprehensive study on the design of a 30 GHz, circularly polarized (CP), single horn-fed, metallic electromagnetic band gap (EBG) antenna. Three different approaches have been studied in order to create a 20 dBi antenna with an axial ratio (AR) lower than 1 dB over a 500 MHz bandwidth. Based on theoretical and experimental results, a conclusion is given on the best solution to obtain the desired characteristics. Perspectives and guidelines are also given for the design of multi-feed EBG antenna as a reflector focal feed for Ka-Band Space Applications.
