TOTAL POWER of a spiral antenna from CST

Hi,

I'm having problems trying to figure out the TOTAL power efficiency of a spiral antenna from CST;

Power efficiency = Useful power / Total power

or

Power efficiency = a / (a + b + c + d)

where
'a' = total power RHCP forward lobe from 90deg to -90 deg
'b' = total power RHCP back lobe from -90deg to 90 deg
'c' = total power LHCP forward lobe from 90deg to -90 deg
'd' = total power LHCP back lobe from -90deg to 90 deg
... (please see figure attached for the labels)

What I'm interested in is finding the whole TOTAL power of respected lobes. But what CST gave is only the Pmax at boresight (ONLY at 1 POINT - 0 deg) i.e. -6.9 dBW/m2 in the example.


Is there any way I can get the TOTAL POWER at RHCP and LHCP forward and back lobes directly from CST?

Hoping that someone can help me with this problem.


Many thanks

Sue