Indented quasi-Yagi antenna array for high-isolation full-duplex radios

An indented quasi-Yagi antenna array is proposed for the purpose of achieving better impedance match by creating and combining out-of-phase return losses from each individual antenna element. The array architecture, jointly with non-reciprocal components such as circulators, can provide higher isolation between the transmitting and receiving paths in a full-duplex radio, without limiting the choices of antenna polarizations and radiation patterns. An antenna array of four meandered quasi-Yagi dipole elements with feeding network is designed and fabricated on Rogers 4350 substrate. The fabricated indented array has demonstrated 16dB average isolation improvement and 13dB return loss improvement over the frequency from 3.3GHz to 3.4GHz.