ON THE DESIGN OF A HYBRID-CHEBYSHEV COLLINEAR FOLDED DIPOLE ANTENNA-ARRAY

The arrangement of a Mast-mounted folded dipole antenna away with corn er reflectors is considered. The method of moments (MoM) in a wire gri d model is used and a suitable optimization procedure is applied. Due to the constraints for high power gain and low SLL the array is design ed as a simple broadside Chebyshev one. The presence of 120 degrees co rner reflectors change the pattern and makes the array to be a Hybrid- Chebyshev one with approximately the same SLL. The distance of the arr ay from the corner of the reflector is critical for the HPBW. Two diff erent types of antennas with 60 degrees and 120 degrees HPBW in the ho rizontal plane for possible mobile applications are studied. The whole design work is given in a general form, useful for VHF and UHF commun ication applications. To ensure the accuracy, two different wire grids for each model are used. In the examples several interesting cases wi ll be analytically presented.