Multiplex cyclic commutation and its applications

It is shown how a rotating set of N circumferentially transposing links can connect N stator inputs commutatively to N stator outputs: thus replacing at least N2 switch contacts and N moving parts (or the equivalent number of relays or solid-state switches) by 2N contacts and a single moving part. The same algorithm permits a set of N rotating contacts, sharing a common track, to retain one-to-one connections with a single track of N stationary contacts. Examples are given of embodiments suitable for: commutation, to time-share test equipment in production testing; multiple slip rings sharing a common-contact track; beam steering for multiple transducer arrays. A number of other possible applications are suggested. The technique has been applied to beam steering for a wide-band wide-aperture circular h.f. antenna array. Here, it enabled a rotary printed-circuit switch to substitute for a capacitive `gonio¿, with dramatic savings in cost, bulk, and production time.