Construction Method and Analysis of Radiation Characteristics of an Ultralarge Array Antenna for Microwave Power Transmission

摘要

When an ultralarge antenna for microwave power transmission is constructed, a promising realization method can be an array of subarray units made of small antennas or an array of aperture antennas. In this case, there are discontinuities of electromagnetic fields between the units or elements so that grating lobes may be generated. In this paper, a method is presented for construction of an array antenna with a diameter on the order of 1 km made of element apertures with a diameter on the order of 10 m. The radiation characteristics are discussed by an analysis. By using the element aperture gap, electric field distribution over each element aperture, and excitation intensity profile over the entire array as the parameters, variations of the radiation characteristics are studied. As a result, it is found effective as a method of suppression of the grating lobe to use the following approaches: (1) the electric field distribution of the element aperture and the aperture dimensions are appropriately selected, (2) the array antenna should have the most densely filled configuration with uniform distribution or cos distribution over each element aperture but with a Gaussian distribution over the entire array.