dissipation loss..........RF, Microwave and Antennas

what is dissipation loss?
.....
what is the meaning of formula for dissipation loss..

dissipation loss = 10 log ((1-(S11^2))/(S21^2)) base10

what does this graph indicates?(attached

Is your equation with the division correct? There is something like dissipation loss, but that is 1-( |S11|^2 + |S21|^2 ). It is the loss in the DUT, calculated from comparing incident power minus reflected power minus transmitted power.

i was bit confused with the dissipation loss relation.....
what outcomes can be drawn from the dissipation loss vs frequency graph?....attached

I think your equation makes no sense with S11^2/S21^2 and so your graph makes no sense.

yes you are right......its
1-( |S11|^2 + |S21|^2 )
and graph is for this equation only.....
And if I'm not wrong .....from graph it can be concluded that loss is minimum for 3-4GHz....
what other outcomes?