DESIGN AND MEASURED PERFORMANCE OF CYLINDRICAL MICROSTRIP PATCH ANTENNA-ARRAYS FOR SDMA-APPLICATIONS

This paper demonstrates the high flexibility and performance of confor mal microstrip patch arrays and their advantageous use in SDMA applica tions. A fast. mathematically simple and robust algorithm for the patt ern synthesis of cylindrical patch antenna arrays is described. It is based on the least mean square (LMS) method and hence does not need an y non-linear optimisation technique. The involved integrals can be rep laced by rapidly converging infinite sums, using the properties of the Fourier series expansion. The described pattern synthesis algorithm a llows a fast and efficient evaluation of all the array excitation coef ficients, which are necessary to generate the required beams for the S FIR or SDMA operation of base stations for mobile communication system s as well as for indoor WLAN systems. As a design example the measured and calculated performance of a conformal 16x4 element cylindrical mi crostrip patch phased array is shown. Excellent agreement between pred icted and measured radiation patterns is achieved.