A wideband circular array for h.f. communications

This paper describes a study of the use of a single ring array of monopoles for a wideband multiple-beam aerial system for communications.Directional patterns are calculated for 24- and 32-element circular arrays over the frequency band 1-5-10 MHz and for different types of array excitation (or element combination in the case of a receiving array).The calculations are backed by experimental measurements on a model circular array operating over the band 200¿1365 MHz. The study shows that low side-lobe levels (¿6 to ¿9 dB) and acceptably small variations of beam-width, can be achieved over the above frequency band.