Series-Fed Microstrip Patch Arrays Employing Metamaterial Transmission Lines: A Comparative Study

The comparison of two different series-fed microstrip patch arrays, designed to radiate at broadside and occupy the same volume, is reported in this paper. The first array is composed of three radiating elements that are interconnected with conventional transmission lines. In the second array, spiral- based metamaterial transmission lines are employed for the series interconnection of the radiating elements. The small length of the metamaterial lines allows for the use of four radiating elements within the volume originally occupied by the first array. The latter approach provides a larger bandwidth of operation, reduced side lobe level and could be used for the synthesis of passive phased arrays with beam scanning properties.