Exponential power delay/decay channel

If I want my channel gain to resemble an exponential power delay profile is it enough to define:

h=  [1 0.66]

if I have two channel taps (i.e memory length of 2) and

h= [1 0.66 0.44]

for three taps? or is it more complicated than that?

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I found this vector

   [1 0.66 0.44 0.29 0.13 0.05]

when googling "exponential power delay profile" source: http://www.mathworks.com/matlabcentral/newsreader/view_thread/67532

I am trying to simulate an optical channel (wireless).. so h must be real and deterministic (not random)