Mutual coupling characteristics of binomial and Chebyshev arrays using 16 element patch antennas with choke for repeater systems

Repeater systems will become practical in the IMT-2000 system in order to provide service in locations where presently radio waves cannot reach. We have examined an antenna structure, in the form of a patch array antenna of 4 elements, for a repeater (Michishita, N. et al., IEE 12th Int. Conf. Antennas and Propagation, 2003). At the edge of the ground plane is a choke structure, and this structure´s parameters effect the FB (front-to-back) ratio. We investigate a 16 element patch array antenna which references the 4 element design method and present the mutual coupling characteristics of the 16 element patch array antennas with chokes. The repression of the FB ratio by a choke is small in the case of the 16 element array, because its side lobe level is large. We examine the effect of restraining the mutual coupling using a binomial and Chebyshev array by controlling the amplitude of each element. The binomial and Chebyshev arrays effect the restraint of the side lobe level, and the mutual coupling can be made less than -100 dB by choosing suitable parameters.