Design an ionospheric radio link over a distance of 2500 Km given that the ionosphere effective height is 275 Km and the electron density N= 2*1011 /m3, namely find :
i- the angle of incidence on the ionospheric layer.
ii- choose a suitable operating frequency (Hint: use f=.85 fMUF).
iii- the required antenna height.
iv- at night N is reduced to 5*1010, find the new operating frequency.