This web site is devoted to my final year project. The project title is "An Expert System for Designing Phase-Locked Loops" (AJF/4), and my project supervisor was Tony Fisher.
The phase-locked loop is a well-studied electronic circuit which is used to lock the frequency and phase of an oscillator onto a given signal, to synthesize signals at rational multiples of a given frequency, to filter noisy signals, and for all sorts of other clever applications. The design of a PLL involves the choosing of values for many parameters, including loop order, damping factor, loop bandwidth and resonant frequency. Different applications demand different choices for parameter values and different loop configurations, and the parameter values interact in a complex way.
A full account of loop design and of the theory behind phase-locked loops is given in Phaselock Techniques by F.M. Gardner or Phase-Locked Loops by Roland E. Best.
The idea of the project is to design a piece of web based software that will guide the user through the complex world of phase-locked loops, so they can then physically implement the design. The suggested language to implement the software in is Java / Javascript, as this will give the user a GUI interface, thus making it more "user friendly", and easier to guide them through the design process.
One solution currently existing is Tony Fishers Interactive Digital Phase Locked Loop Design Package. This is a fairly simple PLL design package implemented in web forms, entry fields and buttons. The user is left on their own when it comes to chosing good and correct values for the design of a PLL.
Below is the basic layout of a phase-locked loop, by clicking on the link below the diagram you will be taken through the design process:
An Expert System for Designing Phase-Locked Loops or if you would like to have a zipped up version of the web site click here: Zipped Web Site