Phase-locked cellular oscillators
Biological oscillators occur frequently in nature---and many systems, such as the growth of certain bacteria, are governed by the 24-hour circadian clock. Furthermore biological phase-locked oscillators, as identified by researchers, are clearly an integral part of the structure of the brain in humans, and in animals in general. Such systems are most conveniently investigated via computer models. This thesis describes the computer-modelling of phase-locked systems in which the oscillator is a cellular automaton---a device often used by scientists to model the growth or decay of populations within biological and other systems. The latter part of the thesis shows how these computer models have been implemented in a two-dimensional form using gate array technology, and results are presented to demonstrate the overall loop performance. It is not suggested that the phase-locked loops described in this thesis should be translated directly into practical commercial products---the primary objective of the research described being to originate a new type of phase-locked loop based around a novel variable frequency oscillator. However, the summary at the end of the thesis indicates how the designs might be modified so as to allow a direct silicon implementation.