Error: Unexpected MATLAB expression. SYNTAX ERROR?!

>> f=10:1:100000; % f is the frequency varying from 10 to 100000 in steps of 1hz
>> G=2483.71*(2pi*f*10)(2pi*f*100)*1018/(60.7*2pi*f*100)*10-9+1)(6.07*2pi*f*10*10-9+1);
>> faxis=0.000001*f;
>> plot(f axis,f,'w',f,G,'r')
xlabel('Frequency, rad/s'), ylabel('Gain, V/V')
title('Frequency Response Plots')
subplot(2,1,2), semilogx(w, phase)
xlabel('Frequency, rad/s'), ylabel('Phase, deg')
>> xlabel ('Frequency in Hz')
>> ylabel ('Voltage in volts')
>> text (6,6,'G(f)')
 G=2483.71*(2pi*f*10)(2pi*f*100)*1018/(60.7*2pi*f*100)*10-9+1)(6.07*2pi*f*10*10-9+1);
             |
Error: Unexpected MATLAB expression.

Hey everyone, how are you? I have this code that WAS working not too long ago but when I come to simulate it, it doesn't wanna work and it spits out this error message. This is for a Bode plot Midband voltage amplifier circuit. I have checked my work and everything and it was working before but I don't see what I changed in it. Anyone have any ideas? Thank you :)

Answer 1

[Marta Salas]

You need to checked carefully what you have written in the definition of G, I have spotted some * missing, there is also a missing bracket (bold one) that I can not figure out where it starts:

G=2483.71*(2 * pi*f*10) * (2 * pi*f*100)*1018/(60.7*2 * pi*f*100)*10-9+1 ) *(6.07*2*pi*f*10*10-9+1);

Answer 2

[Image Analyst]

Why doesn't the G= have a >> in front of it? Is it on the same line as the call to text()? Anyway, that line has for ( but 5 ) so there is a mismatch in the number pf parentheses. Fix that.

[Image Analyst]

Also, there is a missing operation in between ) and ( in

.....-9+1)(6.07*.......

You can't have two parentheses back to back like that.

[Sha Ka]

Alrighty, I did some editing and I saw that I had a few mistakes and I am still coming across the same problem:

>> f=10:1:100000; % f is the frequency varying from 10 to 100000 in steps of 1hz >> G=2483.71*(2pi*f*10)*((2pi*f*100)*(10^18))/((60.7*2pi*f*100)*(10^-9))+1)*((6.07*2pi*f*10*(10-9))+1); G=2483.71*(2pi*f*10)*((2pi*f*100)*(10^18))/((60.7*2pi*f*100)*(10^-9))+1)*((6.07*2pi*f*10*(10-9))+1); | Error: Unexpected MATLAB expression.

>>

[Marta Salas]

write 2pi as 2*pi

[Sha Ka]

>> G=2483.71*(2*pi*f*10)*((2*pi*f*100)*(10^18))/((60.7*2*pi*f*100)*(10^-9))+1)*((6.07*2*pi*f*10*(10-9))+1); G=2483.71*(2*pi*f*10)*((2*pi*f*100)*(10^18))/((60.7*2*pi*f*100)*(10^-9))+1)*((6.07*2*pi*f*10*(10-9))+1); | Error: Unbalanced or unexpected parenthesis or bracket.

>>

I got the same result :/

[Marta Salas]

You still have a mismatch in in the number of parenthesis. The symbol "|" indicates which braket is unbalanced

[Sha Ka]

Alrighty, I got that error fixed, now I'm getting this:

>> f=10:1:100000; % f is the frequency varying from 10 to 100000 in steps of 1hz G=2483.71*(2*pi*f*10)*((2*pi*f*100)*(10^18))/(((60.7*2*pi*f*100)*(10^-9))+1)*(((6.07*2*pi*f*10)*(10^-9))+1); Error using * Inner matrix dimensions must agree.

What does that mean?

[Marta Salas]

Maybe you want to use element-wise multiplication: http://www.mathworks.com/help/matlab/ref/times.html

[Sha Ka]

HEY it worked!!! Perfect! Wow thank you so much for all of your help! I appreciate it very much :D

[Image Analyst]

You're welcome. You can "thank" us by voting for our Answers.

Answer 3

[Pallavi]

G=2483.71*(2pi*f*10)(2pi*f*100)*1018/(60.7*2pi*f*100)*10-9+1)(6.07*2pi*f*10*10-9+1);

Please check this expression which says missing parenthesis.

(60.7*2pi*f*100)*10-9+1) is the problem area with no left parenthesis.