Please help: Frequency/Time domain

[pollop]

Somebody please explain to me in basic terms what:
1 - the time and frequency domains are
2 - what kind of measurements are they used for
3 - what is the most common domain for antenna measurements
4 - can i see an example of antenna measurements in the time and frequency domain

sorry for all the questions, i am a beginner and want to learn fast, hope you can help

thanx in advance

 

[A.Anand Srinivasan]

time domain is when the x-axis is time i.e variation of something studied with respect to time eg:- AC, DC
freq domain is when the x-axis is freq i.e variation of something studied with respect to freq eg:- gain of an amplifier

antennas parameters like directivity and gain vary with frequency and hence antenna can be analysed in freq domain,.... i'm not that sure of the time domain analysis of antenna..........

 

[pollop]

thanks for a quick reply.
I understand the time and frequency graphical representation, it is more about the interpretation of the graphs that is difficult.

Added after 16 minutes:

for example, how would a spectrum analyzer be used to test an antenna?

 

[A.Anand Srinivasan]

maybe you can transmit constant amplitude signal of all frequencies and receive them using the antenna and then check the output signal amplitude corresponding to each frequency using the spectrum analyser and find the gain of the antenna for different frequencies......

 

[RFCMOS]

Hello,

You can find a lot of reference on antenna and their measurements set-up by browsing google.
for example:
www.radio-electronics.com/info/antennas

wireless.ictp.trieste.it/handbook/C6.pdf