Matlab bode plot with specific cut off frequency

This scrip displays a bode diagram however the cut off frequency is incorrect. I need the cut off frequency to be 15kHz whilst showing the gain to be 27dB. Does anyone have an idea how I can achieve this? Thank in advance.

clc

format long

C1 = 0.000000000150;
C2 = 0.000000000470;
R1 = 10000;
R2 = 180000;
R3 = 2700;
R4 = 56000;

G = (R3+R4)/R3;

A = 1/(C1*R2)
B = 1/(C2*R2)
C = (1/(C1*R1))*(1-G)
D = 1/(C1*C2*R1*R2)
E = (A+B+C)


%{
Numerator = {[G 0 0] };
Denominator = {[1 0] [A] [B] [C] [0 D]};
T = tf(Numerator, Denominator)



Numerator = {[G 0 0] };
Denominator = {[1 (A+B+C) D]};
T = tf(Numerator, Denominator)
%}
%{
T = tf([G 0 0], [1 (A+B+C) D]);
%}

%T = tf([21.740 0 0], [1 1.418439716*10^4 5.263157895*10^-6]);
T = tf([G 0 0], [1 E D]);
%T = tf([21.740740740741 0 0], [1 -13778303.125821 7880220646.1781])

options = bodeoptions;
options.FreqUnits = 'Hz'; % or 'rad/second', 'rpm', etc.
bode(T,options);
grid on

Im looking to achieve something like this.

Answer 1

[Star Strider]

The easiest option may be to define the radian frequency function:

w = linspace(0, 1.5E+4, 1E+3)*2*pi;

and then supply it as an argument to bode —

clc

format long

C1 = 0.000000000150;
C2 = 0.000000000470;
R1 = 10000;
R2 = 180000;
R3 = 2700;
R4 = 56000;

G = (R3+R4)/R3;

A = 1/(C1*R2);
B = 1/(C2*R2);
C = (1/(C1*R1))*(1-G);
D = 1/(C1*C2*R1*R2);
E = (A+B+C);


%{
Numerator = {[G 0 0] };
Denominator = {[1 0] [A] [B] [C] [0 D]};
T = tf(Numerator, Denominator)



Numerator = {[G 0 0] };
Denominator = {[1 (A+B+C) D]};
T = tf(Numerator, Denominator)
%}
%{
T = tf([G 0 0], [1 (A+B+C) D]);
%}

%T = tf([21.740 0 0], [1 1.418439716*10^4 5.263157895*10^-6]);
T = tf([G 0 0], [1 E D]);
%T = tf([21.740740740741 0 0], [1 -13778303.125821 7880220646.1781])

w = linspace(0, 1.5E+4, 1E+3)*2*pi;


options = bodeoptions;
options.FreqUnits = 'Hz'; % or 'rad/second', 'rpm', etc.
bode(T,w,options);
grid on

.

[Aaron Frost]

Sorry I forgot to mention that I need to gain to be visible showing 27dB

This is what im looking to achieve but it needs to be with matlab

[Star Strider]

Try something like this —

% clc

format long

C1 = 0.000000000150;
C2 = 0.000000000470;
R1 = 10000;
R2 = 180000;
R3 = 2700;
R4 = 56000;

G = (R3+R4)/R3;

A = 1/(C1*R2);
B = 1/(C2*R2);
C = (1/(C1*R1))*(1-G);
D = 1/(C1*C2*R1*R2);
E = (A+B+C);


%{
Numerator = {[G 0 0] };
Denominator = {[1 0] [A] [B] [C] [0 D]};
T = tf(Numerator, Denominator)



Numerator = {[G 0 0] };
Denominator = {[1 (A+B+C) D]};
T = tf(Numerator, Denominator)
%}
%{
T = tf([G 0 0], [1 (A+B+C) D]);
%}

%T = tf([21.740 0 0], [1 1.418439716*10^4 5.263157895*10^-6]);
T = tf([G 0 0], [1 E D]);
%T = tf([21.740740740741 0 0], [1 -13778303.125821 7880220646.1781])

w = logspace(-3, log10(1.5E+8), 1E+3)*2*pi;


options = bodeoptions;
options.FreqUnits = 'Hz'; % or 'rad/second', 'rpm', etc.
bode(T,w,options);
grid on

Fx = gcf;
Kids = Fx.Children;
MagPlot = Kids(3);
YdB = MagPlot.YLim

YdB = 1×2

-3.000000000000000 0.267445587351631

Ymag = db2mag(YdB)

Ymag = 1×2

0.000000000000001 21.738418068660366

.