## Radio Math Stuff

### Some useful (and not so useful) math for radio applications

Matrix Inversion - complex admittance and impedance
matrices (links to spreadsheets and Matlab stuff)

Exponential Integrals - Sine and Cosine integrals
pop up in mutual impedance calculations

Euler's number (shows up in a variety of places)

Bessel functions - patterns of uniformly illuminated
circular apertures (and FM modulation, too)

Wye/Delta (or T/Pi) transformations

Transmission line equations (including hyperbolic functions)

Transmission line impedance formulae (particularly microstrip, etc.) tlz.htm

Two Port Matrix representations (including conversions
between them)

### Other useful math stuff

A great set of matrix routines for use in Excel. They do complex math, create
admittance matrices, etc. It's just an Excel add-in that doesn't make ANY changes
in your configuration. Delete the files and it's gone.
http://digilander.libero.it/foxes/index.htm

Here are the zip files:

The Excel Add-in http://digilander.libero.it/foxes/matrix18.zip

Documentation:
http://digilander.libero.it/foxes/MatrixTutorial1.zip (This one's just a
big 200+ page pdf after expanding it)

If you use these, you'd better learn about entering matrix functions in Excel
(Ctrl, Shift, Enter). It's in the first few pages of the tutorial, above, and
in the help file with the add in, but takes getting used to.

More Excel: XLZIZL is a spreadsheet that analyzes transmission lines and matching
components by AC6LA. Extremely useful. Kind of slow to download because it's
at qsl.net, but worth the time:
http://www.qsl.net/ac6la/xlzizl.html

radio/math/index.htm - 10 Jan 2005 - Jim
Lux

(Radio Home Page) (Jim's
Home page)