Definition of ground reflection coefficient in phased.Tworaychannel

Hello,

assuming the propagation of a purely vertical polarised FMCW radar uses the phased.TwoRayChannel. Is it correct to calculate the ground reflection coefficient used by the phased.TwoRayChannel property: GroundReflectionCoefficient as

Gamma_v = epsilon_r * sind(tgt_ang) - sqrt(epsilon_r - cosd(tgt_ang).^2)./ ... (epsilon_r * sind(tgt_ang)+ sqrt(epsilon_r - cosd(tgt_ang).^2));

where tgt_ang reflects the grazing angle (90°-angle of incidence) calculated by Matlabs rangeangle function? Since the E-Fields are vertically polarized only I do not want to start using polarization throughout my simulation.

Thank you! Dominic

Answer 1

[Honglei Chen]

This is a valid equation and it could work. Since this is for parallel incidence, i.e., the signal is in the incidence plane, you want to make sure that your signal satisfy that requirement.

HTH

[Dominic Ruh]

just in case someone else will ever use the equation given above. There was one brace lacking that I corrected in here:

 Gamma_v = (epsilon_r_medium2 * sind(tgt_ang(2,2:2:end)) - sqrt(epsilon_r_medium2 - cosd(tgt_ang(2,2:2:end)).^2))./ ...
            (epsilon_r_medium2 * sind(tgt_ang(2,2:2:end))+ sqrt(epsilon_r_medium2 - cosd(tgt_ang(2,2:2:end)).^2));

[Dominic Ruh]

the section on "Ground Reflection and Propagation Loss" from here:

https://de.mathworks.com/help/phased/ref/phased.tworaychannel-system-object.html?s_tid=doc_ta#buw2tng

helped me a lot...