Equations from Yagi Antenna Design

*K* defined as wavelength to radius of element.

- three term approximation

- exponent of wavelength to element radius ratio

__Mutual Impedance__

for *s > 2* wavelengths

Mutual impedance calculated from Uda-Mushiake

__Compute directivity__

Drive voltage to elements

Positions of elements in wavelength.

*X* axis follows boom

Position of elements above or below boom (*y* dimension) in wavelength

Wavelength to element diameter at design frequency

Wavelength over diameter at test frequency

Element length at design frequency

Element spacing

Mutual and self impedances

Element currents from all mutual and self impedances and driving voltages.

Input impedance

__E and H plane directivity__

__Read data files__

Read data from file and converted it to a vector

Number of elements

Set frequency

Define each vector to a constant to make MathCad forget its previous size

Element spacing

Mutual and self impedances

Element currents from all mutual and self impedances and driving voltages.

Input impedance

Mathcad file developed by

**Dr.R****oman N Tunkel**,

04/06/2002

__tunkelr@rcn.com__