s-parameter dipol

Hi, everyone

does anybody know how to measure S parameter of a dipole antenna with a network analyzer? This is the first time I have used a network analyzer, so I hardly know what to do. For i want to know the equivalent impedance of the dipole
antenna, is that the only way I can get it? Somebody help me out! thanks in advance!

Dipole is a balanced antenna and you need a balun (BALanced to UNbalanced) to feed it.
There are a lot of types of baluns that you can use:
http://www.poynting.co.za/tech_training/tut_balun.shtml
After that just connect the unbalanced end to the Port 1 of your Network Analyzer and measure S11 of the antenna.

thank U! Vfone
But i still wonder the two inputs of the antenna is connected to the Balun, but how to deal with the other side of the dipole? Nothing connected? If convenient, would U mind drawing a picture for me! Thank U so much!

You don?t have to connect the other ends of the dipole to something. Actually should stay far from other objects.

got it
you can bend the other ends to get a good direction

but if use balun to converte the two input into sigle port that will be connected to Network Analyses, measurement results will contain the effect of balun, how can i eleminate it, and get the net impedance of dipole through S11?
and if i use ADSmomentum simulate the dipole , do i need draw the balun on the layout? actual dipole antenna don't contain the balun, having two input, how to set the port type? differential port or internal port plus ground reference?

thanks a lot!

Hi hxr

if you know a member of ARRL you can ask him to get for you the
pdf file about dipole.

look at http://www2.arrl.org/tis/info/dipole-h.html
sub. Feeding Dipole Antennas

PL