Cal_RSP_kxy_Single.m

function [RSUp, RPUp, RSDn, RPDn, RS21, RP21, RS12, RP12]=Cal_RSP_kxy_Single(num_dl, Eplist, dl, klz, nUp, nDn)

 %The reflection coefficients
    RP21 = zeros(num_dl);
    RP12 = zeros(num_dl);
    RS21 = zeros(num_dl);
    RS12 = zeros(num_dl);

    for l=1:num_dl
        RP21(l) = (Eplist(l) * klz( l + 1) - Eplist(l + 1) * klz(l))./(Eplist(l + 1) * klz( l) + Eplist(l) * klz(l + 1));
        RP12( l) = -RP21( l);
        RS21(l) = (klz(l + 1) - klz(l))./ (klz(l) + klz(l + 1));
        RS12(l) = -RS21(l);
    end
    % For The Upper layer
    RPUp = 0;
    RSUp = 0;

    for m=1:nUp
        l = num_dl - m+1;
        exp11 = exp(-1i * (klz( l+ 1) - klz( l)) * dl(l));
        exp12 = exp(1i * (klz( l+1 ) + klz( l)) * dl(l));
        exp21 = exp(-1i * (klz( l+1) + klz( l)) * dl(l));
        exp22 = exp(1i * (klz(l+1 ) - klz( l)) * dl(l));

        RPUp = (RPUp.* exp11 + RP12( l).* exp12)./(RPUp.* RP12( l).* exp21 + exp22);
        RSUp = (RSUp.* exp11 + RS12( l).* exp12)./(RSUp.* RS12( l).* exp21 + exp22);
    end
    %For the lower space
    RPDn = 0;
    RSDn = 0;
    
    for m=1:nDn
        l = m+1;
        exp11 = exp(1i * (klz( l - 1) - klz(l)) * dl(l - 1));
        exp12 = exp(-1i * (klz(l - 1) + klz(l)) * dl(l - 1));
        exp21 = exp(+1i * (klz(l - 1) + klz(l)) * dl(l - 1));
        exp22 = exp(-1i * (klz(l - 1) - klz(l)) * dl(l - 1));
        

        RPDn = (RPDn.* exp11 + RP21(l - 1).* exp12)./(RPDn.* RP21(l - 1).* exp21 + exp22);
        RSDn = (RSDn.* exp11 + RS21( l - 1).* exp12)./(RSDn.* RS21(l - 1).* exp21 + exp22);
    end
end