Theory and techniques of power distribution systems of microwave multi-channel arrays

Abstract

There are two trends in the field of array design: the 1-st is that receiving arrays are formed by using the fiber-optics signal distribution circuits; the 2-nd is that transmitting arrays are designed with application of feeder or space power distribution system (PDS).

In this paper, more than 20 years of the author’s practical experience in designing the feeder multi-channel PDS is generalized.

PDS is a structure consisting of a large but finite quantity of elements with a number of accessible inputs and outputs, through which the electromagnetic energy is transmitted. Transmission lines, two-channel or cyclic devices, inhomogeneities, and other elements are the components of PDS.

PDS theory includes the methods of microwave multi-channel circuit and element frequency characteristics analysis; methods of PDS structures synthesis with a desired amplitude and phase distribution; methods of statistical analysis; methods of evaluation of wave amplitudes and phases in PDS internal circuits; three-arm divider theory; theory of cyclic devices based on transmission line combinations; cyclic algorithms for the evaluation of PDS and their components that are based on the idea of a deliberate consequent association of one or two pairs of arms, and the device characterization with the aid of recurrent formulas; mathematical models of PDS elements.

As examples of the theory application to practical task solutions, the results of PDS modeling for several thousand channels are presented. Also, sample synthesis of wide-band and cyclic devices and three-arm dividers based on transmission line combinations, with arbitrary division ratio and various load resistance’s is demonstrated. The techniques of PDS optimization by the feeder lines length modification are shown. The dissipation losses and distributed loads influence on the characteristics of PDS as a whole are presented as well.

Techniques of PDS are illustrated by the fragments of 128-channel system, 8-channel power divider, two and four-channel dividers (summators) for a high power level based on high-quality transmission lines.