In front of the blog we have emphasized the importance of the signal system is omitted here, the main section to analyze the transfer function of the relationship between the Bode plot, and draw the corresponding Bode diagram of the transfer function.
The section from the amplitude-frequency characteristic with the frequency characteristic expression starts, the lead and further the relationship between the transfer function of the Bode plot, the relationship mathematical approximation, amplitude-frequency, phase-frequency characteristic curve can be plotted by the analysis is complete, the two given complex the transfer function shown by approximating the corresponding Bode plots, using the model simulink matlab simulation inside the control, to obtain consistent and theoretical results, a simple circuit analysis shows to be introduced into the final low-pass high-pass characteristic, and to matlab simulation as the end .
The frequency characteristics of the circuit which is more abstract mathematical model transfer function characterized, i.e. a description of the circuit varies with frequency characteristics, conclude the following:
Amplitude frequency characteristics:
. A is a single zero slope jw + 20dB / decade line
b-pole (1 / jw) is a slope of -20dB / decade line.
C if multiple pole or zero, each time re-root. , pole -20dB / dec zero + 20dB / dec, for example:.
S ^ 2 zero 40dB + / On Dec
S ^ zero. 3 60dB + / On Dec
. 1/2 ^ S pole -40dB / On Dec
. 1 / pole. 3 ^ S -60dB / dec
d., and by the start and end of order pole-zero substantially determines the trend of the curve
Phase-frequency characteristics:
. A zero position on jw is the complex frequency domain (0, w) is a positive angle to the axle + 90 °, + 90 ° to the contribution of phase-frequency characteristic
b position of the pole 1 / jw in the complex. the frequency domain (0, -1 / w) and the positive axis angle of -90 °, -90 ° to the contribution of phase-frequency characteristic
c. contribution single zero up to + 90 ° phase shift
d. contribution-pole up to -90 ° phase shift
e. by its start and end points of order pole-zero substantially determines the trend of the curve
