How to plot this equation and get this curve??

Here is the equation :

T = 10.^(-A/20)

The plot of A vs C is :

My code so far:

N = 15;
C = linspace(0, 35, N);
A = linspace(0, 10, N);
T = 10.^(-A./20);
X = sqrt(1-C.^2);
Y = 1-T.*X;
PG = (C/Y).^2;

for a1 = 1:numel(C)
    for a2 = 1:numel(A)
        X = sqrt(1-C.^2);
        Y = 1-T.*X;
        PG = (C/Y).^2;

        plot(C,A);
        xlabel('C (dB)');
        ylabel('A (dB)');
        title(sprintf('Power multiplication'))
        
    end
end

Answer 1

[Alan Stevens]

The following plots the curves:

Cfn = @(CdB) 10.^(-CdB/20);
Tfn = @(C,M) (1 - C./M.^0.5)./(1 - C.^2).^0.5;
Afn = @(T) -20*log10(T);

Mvals = [2, 5:5:20, 30, 40, 50];
CdB = 1:0.05:24;
C = Cfn(CdB);
str = [];
for j = 1:numel(Mvals)
    
    M = Mvals(j);
        for k = 1:numel(CdB)
            T = Tfn(C(k),M);
            A(k) = Afn(T);
        end
        A(A<0)=NaN;
    semilogy(CdB,A)
    hold on
    str = [str;sprintf('%4d',M)];

end
axis([0 28 0.01 10] )
grid
xlabel('C [dB]'), ylabel('A [dB]')
legend(str)

[STP]

Hi, thankyou. Semilogy is new for me. :)

How to go about to get different values on X-Y axis for eg. M on Y and A on X (for different C), etc etc along with the current one?

[Alan Stevens]

As follows:

Mfn = @(C,T) (C./(1-T.*(1 - C.^2).^0.5)).^2;
CdB = 4:4:16;
C = Cfn(CdB);
T = 10^-5:10^-3:1;
AdB = Afn(T);
str = [];
for j = 1:numel(CdB)
    
        for k = 1:numel(T)
            M(k) = Mfn(C(j),T(k));  
        end
        
        semilogx(AdB,M)
        hold on
        str = [str; sprintf('C = %4d', CdB(j)) ];
end
grid
xlabel('A [dB]'), ylabel('M')
legend(str)

Or with CdB = 10 and 12:

Note that this matches your last image only if the C values are positive, rather than the negative values on the image.