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Antennas and Microwaves

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Welcome to my Antennas and Microwaves page, I hope you find your visit interesting and informative.  As a practicing Antenna engineer for some 14 years, this page probably comes under the heading “old habits die hard”. However,  the site’s existence may go some way to proving that life in rural France hasn’t turned me into Banjo playing hillbilly just yet - close friends have their own opinions on this!

 

The contents are basically things that I have found interesting or useful over the years or that I am still tinkering with.  

Contents

> How  to make yourself a reference dipole. Designs are best suited for the frequency   range 800-3000Mhz but could be scaled outside this band with a little experimentation.

> A few of the projects I have worked on.

> A practical look at the surface currents and voltages on some common antennas.

> Calculating balanced impedances from single ended S-parameter measurements.

> Defining, evaluating and using coordinate transform matrices.

> Vector Network Analyser script for WinSpice3, including Noise Figure analysis in a Microwave system.

> Useful links

> A scalable design for a circularly polarised Reflect Array . Presented in 3 pages that include  NEC model, design spreadsheet, construction details and measured results.

> Low cost prototyping of microwave PCBs using a desktop sign maker.

> During a trawl of the web, I decided to have a look at what freely available alternatives there were to the ubiquitous Matlab, this is my two-penneth on the subject.

> A collection of m-files that allow plotting of Smith Charts, Admittance Charts etc.  Also Time Domain Reflectometry (TDR) for balanced and un-balanced transmission lines, using standard to mixed mode S-param conversion.

> A Toolbox to assist in the design of phased arrays. Arrays can be defined in 2D and 3D and constructed using a variety of element models. These include :  patch (circular and rectangular) , helix, user defined and interpolated (using external data).

> A  fairly comprehensive technical note, with emphasis on the practical side. Covering by way of an example, array aperture theory, array specification, power splitter design and mutual coupling correction strategies.

> A nice little demo of the Heisenberg’s uncertainty principal using RF test kit.

> An electro-mechanical phase shifter for those on a tight budget. Specification includes 360deg phase shift at 2.45Ghz, 13dB return loss, 1dB insertion loss and direct control via PC parallel port.

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> If you have any comments or suggestions, here’s the place to scribble.

> Or e-mail directly, here.

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> An active phased array demonstrator, using the very low cost phase shifters.

> A Solar Flare Detector using a loop antenna, PC and Spectrum Lab software. This was a more of a general interest project so I’ve put it in the ‘Tech Shed’ along with some other fun projects.