Finding frequency corresponding to some gain in magnitude plot of bode

37 次查看（过去 30 天）

Sunil Kumar Giri 2019-5-9

2
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/461110-finding-frequency-corresponding-to-some-gain-in-magnitude-plot-of-bode

评论： Star Strider 2022-7-26

Hi Community members !

Can you please help me in getting a solution to my problem? I have a transfer function e.g. G(s) = 144000/(s*(s+36)*(s+100)), bode plot of which is given. The magnitude plot passes through -3.76 dB gain at some particular value of frequency. I want to access that particular frequency value using MATLAB program.

Thanks !

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Star Strider 2019-5-9

7
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/461110-finding-frequency-corresponding-to-some-gain-in-magnitude-plot-of-bode#answer_374280

在 MATLAB Online 中打开

Try this:

s = tf('s');
G = 144000/(s*(s+36)*(s+100));
[mag,phase,wout] = bode(G);
mag = squeeze(mag);
phase = squeeze(phase);
wq = interp1(20*log10(mag), wout, -3.76);               % Find Desired Frequency
figure
semilogx(wout, 20*log10(mag), wq, -3.76, 'r+')
grid
text(wq, -3.76, sprintf('\\leftarrow -3.76 dB at %.2f rad/sec',wq), 'HorizontalAlignment','left', 'VerticalAlignment','middle')