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HFSS 13 Radiation Efficiency Well over 100%

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Jack_Swift

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I see there is already a couple of threads about this radiation problem occuring among antenna designers, however, I think my problem was so bizarre that I wanted to open a new thread( most problems I see are right over the 100% line like 101%). I already took an antenna class so I know that efficiency =

(mismatch losses) * ( conduction losses) * (directivity)

where mismatch losses = (1 - abs(Γ))^2 and Γ = (zin - zo)./(zin + zo), this makes it clear that efficiency cannot go over 100%

so why is HFSS v.13 giving me an efficiency of 350%??

I am also aware of meshing and have already tried that, but the problem persists.

Here is a print-screen:

View attachment efficiency.bmp

PLEASE HELP !!!
 

Quick! Patent that suckah! I could use one of those in a number of applications.


the accepted definition is something more like "total radiated power / total accepted power". Sounds like either you set up the calculation wrong, or HFSS simply made a computational error.

**broken link removed**
 

ahaahaha......I am not gonna patent that sucka yet, soon when I am done, it is a MIMO antenna project that uses the GCM bands and WLAN, Bluetooth bands. You should read the article you sent me and read what I said......its exactly what I said( regarding how prad is calculated). I am not sure how HFSS solves things, it has its problems but I love the software.
 

If anyone else has any other suggestions........I already trying meshing ( lamda/10 @ the first resonant frequency). The S11 has a good resonance ( following -6 dB criteria) @ 700 MHz-800MHz, 2.4-2.5 GHz, 2.8-2.9GHz, and 4.33-4.5GHz, however I believe that these are higher order modes thus very inefficient. I just dont understand why there is a spike in one area. If anyone else can help me that would be great!!!
 

You guys are idiots ^

Don't help if you don't know :)
 
Yeah dude......some guys are so stupid their middle names should be " dumb_fuck".....and please don't send me some stupid .pdf .....
 
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    RafidD

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You guys really make me laugh! WE are not the ones who are confused about thinking our antennas are 350% efficient!
 
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Hey ... the only reason you responded with your bullshit answer is to get more points.....stop being a nerd everyday....i bet your on here and facebook all day probably world of warcraft too!! If you don't have a good answer don't respond at all.........papa don't take no mess...ohwwwwwwwwwwww
 

Calm down. As the others wrote, it must be something trivial. Why don't you check your integration area (sweep range for theta and phi) for the radiated field? It's very likely that you sampled the same angles multiple times.
 

Not sure why you are getting bent out of shape. The argument I proposed is a logical one:

1) an antenna can not be greater than 100% efficient. If you do not believe that, read a fundamental book on thermodynamics some day.

2) If 1 is true, then either:
a) your software is incorrectly written,
b) you input the data incorrectly
or
c) your definition for "efficiency" does not follow engineering norms, and therefore is not bound by 100% max efficiency rule 1) above.

If you have a logical response, we are willing to listen.


OT: if anyone has a use for points, PM me, I have no use for them
 
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