Phased-array beam steering by multiplex sampling

Abstract

One approach to phased-array antenna beam forming and steering is to multiplex the element signals into a single channel. Appropriate sampling of the resulting multiplexed signal can provide electronically steered and shaped beams. This paper describes four practical system concepts for linear and ring arrays based on this approach and discusses significant interrelationships between the various concepts. For linear arrays of elements, the two alternatives are to frequency or time multiplex the element signals. Frequency multiplexing of the element signals produces time-multiplexed beam output signals, and time multiplexing the element signals produces frequency-multiplexed beam output signals. It is also shown here that appropriate correlation sampling may be used with either of these to produce easily one or more continuously and electronically steered signal bandwidth beam outputs. Ring arrays of elements may be multiplexed and sampled in a somewhat analogous pair of techniques. It is also pointed out that the beam steering in this case may be visualized as the linear phase steering of a set of linear phase modes into which the signal received at the array may be resolved. Ring array beam forming and steering may thus be directly understood in terms of the previous linear array techniques.