Bode function - poles and zeros

I have the following transfer function : G = 1/(2*(s*1E-2)*(1+s*1E-2));

I am looking to draw the phase and magnitude plot for this function. I used the following script :

s = tf('s');
G = 1/(2*(s*1E-2)*(1+s*1E-2));
bode(G)                                               
[mag,phase,wout] = bode(G);

Is my aproach correct and if it is, can someone explain to me what are the poles and the zeros for the function ?

My guess is that I have 2 poles : one in 2*E2 and one in 1*E2. Is this correct ?

Answer 1

[Star Strider]

The pzplot function:

s = tf('s');
G = 1/(2*(s*1E-2)*(1+s*1E-2));
bode(G)                                               
[mag,phase,wout] = bode(G);

figure
pzplot(G)

shows one pole at -100 and another pole at 0.

Note that there is an error in the coding for ‘G’ that I corrected. There is either a misplaced parenthesis or a missing multiplication operator. The poles remain unchanged regardless how I permute those corrections.

[Grigorie Vlad]

Ok, but can you help me understand how the 2 constant is influencing the magnitude plot ?

[Star Strider]

It is (obviously) dividing the magnitude by 2, however it is not affecting the pole locations because it multiplies the enitre denominator.

[Grigorie Vlad]

Sorry, but I still not undertand. I ploted the function with and without the 2. All I see that changed is that the magniture plot started from 40 dB(without the 2 constant) and from 34 dB(with the 2 constant). I am having problems understanding how that came to be.

[Star Strider]

Very simply:

Calc = 20*log10(1/2)

produces:

Calc =
    -6.0206

[Grigorie Vlad]

Ah I think I understand the magnitude plot. One more thing : the phase plot does not change at all, is that correct ?

[Star Strider]

That is correct. The phase plot should not change.

[Grigorie Vlad]

Ok, now it is all clear. Thank you very much for the answer and for your time !

[Star Strider]

As always, my pleasure!