Gaussian beam power distribution

Power distribution of a microwave Gaussian beam

A microwave beam density distribution on a surface P_beam (x,y) may be expressed as
P_beam (x,y)=P_tot (2/(pi*wx*wy)) exp⁡(-2(x^2/(wx^2 )+y^2/(wy^2 ))),
where, wx and wy are the characteristic dimensions of the microwave beam with a Gaussian distribution and P_tot is the total power of the beam.
The shape of the power beam isolines are in the form of ellipses defined as
(x/a)^2+(y/b)^2=1
where, x and y are the dimensions of the launcher mirror, in the x and y coordinates, respectively, and a and b represent the lengths of the semi-major axis and semi-minor axis, respectively, considering a > b.
Inputs:
Ptot=1E6; % Total power of the beam [W]
wx=62.9E-3; % Characteristic dimension of the beam %in the x coordinate[m]
wy=50E-3; % Characteristic dimension of the beam in %the y coordinate[m]
xmax=100.7E-3; % Dimension of the surface in the x %coordinate[m]
ymax=80E-3; % Dimension of the surface in the x %coordinate[m]
N=6; % Number of isoline divisions
Outputs:
P_beam (x,y) plot
Table (Isoline,a,b,Power)