how to find efficiency in hfss

[cyberspace9]

dear all
can anyone plz tell me how to find efficiency in hfss.
i mean how to plot (efficiency vs frequency ) graph in hfss ?

thanks

 

[pir0texnik]

Just plot in far field plot. There are a few types of efficiensy. It woud be time consume if your frequency sweep has very many points.

 

[si14]

I think the losses are not very accurate in HFSS. So the efficiency is not accurate. Does anyone has any measurements and compared to simulations?

 

[cyberspace9]

thanx
inside far field, i can find only radiation efficiency (inside antenna params).

can you plz elaborate more what to click step by step to find efficiency?
thanx again

 

[Ivan_]

Ok, if u want to evaluate antenna efficiency, from antenna theory u know that
G=ηD, being G the gain, D the directivity and η the efficiency that keeps into account for losses. If u are using the definition of 'realized gain' in HFSS, u are including all dielectric, ohmic and mismatch losses. Otherwise, the normal gain definition allows to keep into account only for ohmic and dielectric losses. Then, the efficiency is η=G/D. If G=D, ur efficiency is 1 but this is just an ideal case. What I suggest is to create an output variable called 'efficiency' defined as the ratio between the gain (the one u choose) in mag and the directivity in mag along the direction of the global maxima (i.e. broadside).

I.

 

[pir0texnik]

I use "RadiatedPower" for efficiency estimation. If your antenna is excited by 1W you'll get part of radiated outside the air box power including ALL losses within the confines of the calculation domain in %.

PS: Results->Crate far fied plot->Antenna params->RadiatedPower