What antenna parameters say to u.. Share..

Antenna parameters are very basic but important... Pls share your experiences about what your design parameters says to you. This can help many new comers and can also help the experts... So.. Keep sharing.

It is impossible to say what is important without considering the specific application because it changes so much. For satellite communications, directivity and polarization purity are very important. For handheld devices, directivity is usually a bad thing and polarization impurity is more tolerable. In high power systems, a good impedance match is very important, whereas in low power receivers it is not.

If I want a quick assessment of the performance of an antenna, I will look a plot of S11 vs frequency and the pattern plot at the center frequency. Again, the application may have very special requirements beyond this.

Antenna design follows the system specifications. For communication, antenna gain and radiation pattern are important. Any antenna should be matched to line impedance (50 Ohms or waveguide) for a good result.
What is your application?

Thanks... This is exactly what I am expecting through this forum...

How u study radiation pattern and what is the best selection of theta and phi.
Sometimes return loss is good enough to explain the performance of system but corresponding gain is very poor and vice-versa.

Explain...

1.Theta and phi value 90 degree is best but, i can not assure without knowing antenna structure and frequency
2.use optimetrics to find the exact parameters then you can get good result