A two-layer self-diplexing antenna using a circularly polarized ring patch antenna

Isolation between the transmitting and receiving antennas due to orthogonal circular polarization has been investigated for a two-layer self-diplexing antenna. The total isolation due to the polarization and the frequency separation was shown to be more than 35 dB by the experiments. The isolation due to the orthogonal circular polarization was more than 22 dB. The isolation can be estimated according to the axial ratio of far-field radiation patterns. The antennas can be used as mobile terminal antennas for satellite communications.<>