Phase Center Study of the Electromagnetic Band Gap Antenna: Application to Reflector Antennas

Recent studies have shown that the electromagnetic band gap (EBG) antenna can be used to feed a reflector, especially to realize multibeam coverage with geostationary satellite. However, it is necessary to evaluate its performances in terms of aperture efficiency to compare this solution to the classical ones. Among all the parameters which contribute to the aperture efficiency, one of the most important is the phase center, which has never been determined for EBG antennas. This is the aim of this letter. After defining a simple method to calculate the phase center of the EBG antennas, the position and the frequency evolution of this parameter will be studied. Then, the performances of such a feed associated with a Side Fed Offset Cassegrain Antenna (SFOCA) will be evaluated and compared with a classical feed for reflector, a Potter horn