Cross Polarization Measurement

Dear all,

I've projected a Vivaldi antenna with the auxiliary of CST Microwave Studio. After the realization of the antenna, I've measured the far field radiation pattern using the anechoic chamber. The measured and the simulated co-polar radiation pattern are not so different. In particular the behaviour of the two curves is almost the same; obviously the levels of the patterns are different. Instead, the comparison between the measured and the simulated cross-polar radiation pattern shows a deep difference. What can I deduce from this? Are there any justifications?

Thanks for your help!

What antenna did you use as reference antenna for cross-polarization measurement? All antennas (even dipoles) have their own cross-polarization that have to be taken into account.

I used a standard gain horn as reference and I used the three point method to calculate the values of the radiation pattern of the AUT...