Matching for electrically long antenna

[Shika93]

I need to simulate a monopole antenna in 1-5 MHz band. At this frequency, the monopole is very long, therefore I define a simple dipole (10 cm long) in CST, analyze it, export the touchstone for Z11 and use the complex conjugate of Z parameters (in 1-5 MHz) in order to make this antenna resonate. The Z* would act like an active matching circuit. I don't need to design such circuit, since I only need the coverage pattern of this monopole installed on a structure.
Through the Combine Results in the schematic task i obtain the pattern. The problem is that conbined result is identical to the 3D results, so pattern identical.
It doesn't make sense, since the non-matched S11 is mostly 0 dB flat between 1-5 MHz, while the S11 using Z* goes below -100 dB in that band.
I would expect a different pattern.

Someone tried similar solution without defining an active circuit? I also don't know how to desing such circuit in any case.

 

[volker@muehlhaus]

The problem is that conbined result is identical to the 3D results, so pattern identical.

You need to be careful what pattern you look at.
The default gain pattern in many EM tools assumes that your antenna is driven with a port that matches the antenna impedance, i.e. you don't see loss from mismatch. But there should be some setting/option to include mismatch loss.