On the theoretical functioning of some types of centimetric linear arrays

The functioning of linear arrays is explained in terms of familiar filter theory. Three basic types of array are considered, particular attention being paid to the non-resonant array, and the theory of each is investigated, first of all for an array consisting of radiators free from mutual interaction and then for a more general case. It is shown that the non-resonant array has a wide frequency band and that the design is in no way critical, but that the beam direction changes with frequency and that a truly broadside beam is unobtainable. Resonant arrays necessarily produce truly broadside radiation but their impedance characteristics limit their use to applications requiring only a very small frequency band. The leaky wave-guide type of array is only applicable when beams are required at comparatively large angles to the normal, and for this reason little work has been done on this kind of array. It is concluded that the non-resonant array is at present the most generally useful type, both on account of its inherent characteristics and the fact that most of the necessary experimental information has been acquired.