new jap wrote:
Hi Alan,
the i is in the right place as this will imply that it is of a harmonic nature, i.e. in cosine and sine terms. Without i, we get just a loss factor, which is why there is no i infront of alpha (the authors call this the loss decay constant). Also, the exponential terms with alpha always get a minus sign in the front to imply that it is a decaying exponential, i.e. loss. Beta, on the other hand, represents the propagation constant which can travel in opposite direction (hence plus and minus signs are possible) and for which i is necessary.
Yes, I was afraid you were going to say that! Oh well!
I've just noticed that your calculation of k has a numerical value of 4.xxxx. This means that sqrt(1-k^2) will be imaginary, so this will introduce imaginary components into the bowsq function. Also, since phi hasn't been eliminated, a non-zero value will also keep imaginary components in bowsq.
Alanm