[500 points] Comparing harmonic radiation patterns in HFSS

[si14]

antenna radiation patterns normalized

Hi all:

I want to compare my harmonic radiation patterns in HFSS?

I have two antennas:
1) reference
2) improved antenna that has a reduced second harmonic radiation

I expect that the radiation of the 2nd antenna in the 2nd harmonic would be lower than the radiation of the 2nd harmonic of the reference antenna. but the both radiations are equal and even the second antenna has better radiation(more radiated power) in the 2nd harmonic!!!

I am not sure whether I am seeing the correct answer in HFSS. The only thing that I can guess is that the radiation patterns are normalized ones.

Use PM to contact me. Also I am in hurry.

Thanks.

 

[si14]

antenna radiation harmonic

Hi all:

I haven't still get the answer. Does any one know how to compare the radiation patterns for an antenna in any software, doesn't important. In papers, there is only the measurement results, no simulation. I am wondering if it is possible to do the simulation for this purpose.

Do you have any idea?

Thanks.

 

[aboutfunk]

Re: [500 points] Comparing harmonic radiation patterns in HF

1. Yes, in general the RP are normalized. You should consider not only the radiation pattern but the input impedance of the antenna at each frequency. At the end what is important is the radiated power in terms of the applied power at the input of the antenna.
Let's say that at frequency f1 your antenna has S11 = -20 dB and a maximum directivity of 5 dB. At frequency f2=2f1 the antenna has S11=-2dB (is not adapted) and the maximum directivity is 10 dB. What do you think is the better case in terms of the total radiated power. Evidently the first one.

2. However, this depends on your optimization goal. If you are more interested in the beam width of the antenna, the normalized RP at each frequency is enough.

3. What kind of antennas are the reference and the optimized.

bye

 

[grendhell]

Re: [500 points] Comparing harmonic radiation patterns in HF

I'm not sure if I understood what you are looking for, but in HFSS you can plot the gain of the antenna, which already takes into account the efficiency.
You could also compare both gain and efficiencies of the two antennas at the frequencies of interest.
I also find useful to export the data I'm interested in, such as gain, efficiency or whatever else in a csv file and then post-process the data with matlab/excel/etc.

I hope this helps you

 

[shazdek0ch0l0]

use cst and hfss
and compare these patterns!

am i correct?

 

[ksugahar]

use MoM to compare the results.

CST and HFSS both solve for closed spaces.