A mobile radio antenna system having a self-diplexing function

A coupled N-element antenna system on a mobile unit for simultaneous transmission and reception is discussed. A diplexer is required when an antenna for transmission and that for reception are installed with mutual coupling between them. An attempt is made to reduce coupling between the transmitting point and the receiving point by a lossless network and coupled antennas. The network is connected between the antenna and the input and output ports. The decoupled antenna is analyzed and theoretical and experimental results, which show the feasibility of the antenna system, are described.