# Get FIR Hilbert coefficients from Matlabs envelope() function

How can I get the used Hilbert filter coefficients from the Matlab function envelope()?

filter_length = 10;
[up1,lo1] = envelope(input_data, filter_length,'analytic');


The filter is created by windowing an ideal brick-wall filter with a Kaiser window of length fl and shape parameter $$\beta = 8$$.
$$h[n]=\begin{cases}\frac{2}{n\pi},& n\textrm{ odd}\\0,&n\textrm{ even}\end{cases}\tag{1}$$