An investigation into the factors controlling the economic design of beam arrays

The engineer, faced with the problem of designing beam arrays for transmission and reception purposes, should satisfy himself that his proposals are technically and economically sound. He thus requires to know the anticipated performance and cost of each section of complete array systems, to enable him to arrange an equable balance between gain in distant field strength and capital outlay needed to obtain this gain. The factors concerned in the solution of the problem are:- (1) the angle of elevation of the axis of the main lobe of radiation of the beam to give the highest gain in field; (2) the economical design, fabrication, and erection, of structures to support the array; (3) the most economical type of feeders and transmission lines to use, having regard to the energy losses and pick-up of the lines. These three factors are investigated in the paper, and, from the results of the investigation, deductions are drawn regarding the gain of a horizontal type of array composed of numbers of half-wave radiators grouped in various ways. It is shown that the cost of array systems increases rapidly not only with wavelength but also with the angle to the vertical at which the radio energy is required to be projected or received.