Analysis of a circular array of monopoles using a radial guide field matching method

A radial guide field matching method (RGFMM) is used to analyse a circular array antenna consisting of one active monopole surrounded by a concentric array of passive monopoles terminated in arbitrary loads. An equivalent admittance matrix for this antenna system is determined to study the input admittance of the active monopole when the peripheral elements are terminated in open or short circuits. It is shown that the effect of the radial guide height in RGFMM on the input admittance of the active element becomes negligible when the guide´s height is of the order of one wavelength. RGFMM results are compared with free space method of moment (FSMoM) results for a small switched-beam array of 7 monopoles. Good agreement is noted.