Modular approach to the development of a two-way radio receiver system

[摘要] ENGLISH ABSTRACT: The preliminary development of a FM radio receiver module is discussed. An existing narrowbandsystem operating between 48MHz and 50MHz will be replaced. Digital components wereinvestigated, compared and used with analogue techniques to build a more flexible two-way radioreceiver system. A direct digital synthesizer was considered as a replacement for the currentsynthesized phased lock loop local oscillator and much attention was given to the local oscillatorand mixer design, characteristics and measurement procedures.A detailed study of receiver systems was undertaken to determine the specifications needed forevery receiver component to achieve satisfactory receiver performance in the end. Receivercharacteristics as well as receiver measurement procedures are defined. A software tool wasdeveloped to aid the design process, establishing computationally whether the receiverspecifications are met prior to the final design.The complete design process, from fundamental specifications through to the developed finalreceiver module is discussed. A modular design approach was used to guarantee easymanufacturing, substitution and testing. This approach comprises the break-down of the receiverinto well defined components that are each matched to 50O. The separate components of thesystem were designed, measured and characterized to make it possible to replace only a singlecomponent instead of the entire system when a part becomes redundant.

[发布机构] Stellenbosch University