TRANSMISSION LINE FORMULAS

Phase constant: B = 6.28/LAMBDA
Input impedance of line length L: Zl = Zo * (Zb + jZo * tan(B * L))/ (Zo + jZb * tan(B * L))

where:
Zb = load impedance
Zo = characteristic impedance of line

Impedance of short circuited line length L: Zsc = jZo * tan(B * L)
Impedance of open circuited line length L: Zoc = -jZo * cotg(B * L)
Impedance of line an odd number of quarter wavelengths long: Z = (Zo * Zo) / Zb
Impedance of line an integral number of half wavelengths long: Z = Zb
Voltage Standing Wave Ratio: SWR = Zr / Zo or Zo / Zr; Zr = R (Imaginary part is 0)
Voltage Standing Wave Ratio: SWR = (1 + SQRT(Pref / Pfor))/(1 - SQRT(Pref / Pfor))

where:
Pfor = forward power
Pref = reflected power

Voltage Reflection Coefficient: /r/ = (SWR - 1)/(SWR + 1) = SQRT(Pref / Pfor)
Return Loss: RL (dB) = -20 * log(/r/)


RF LINKS

http://www.qsl.net/wb6tpu/swindex.html - The unofficial Numerical Electromagnetic Code (NEC) Archives. Plenty of good antenna freeware.

http://www.rfglobalnet.com - Information source for the RF and Wireless Design industry

http://www.cebik.com - Many useful info about antenna modelling, books, tips, tricks,....

http://www.antennex.com - Another good antenna web site