Enhanced Isolation Between Two Closely Spaced Vivaldi Antennas Using a Rasorber Wall

An effective method for enhancing the isolation between two Vivaldi antennas using a metamaterial wall with rasorber is proposed in this work. The mutual coupling is reduced by adding the rasorber wall, which can absorb the electromagnetic (EM) interference energy from the transmitting antenna to the receiving antenna. The designed rasorber wall is constructed by two kinds of frequency selective surface (FSS) and foam substrate. Due the good absorption of the rasorber structure, the isolation between antennas has enhanced by more than 15 dB on average at X band.