Difficult Understanding Magnitude and Phase Shift of Transfer Function

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SUMMARY

The discussion focuses on understanding the magnitude and phase shift of a transfer function, specifically addressing the transition from the initial equation to the equations for magnitude and phase shift. The participant highlights confusion regarding the calculation of the magnitude from the complex denominator and the presence of a negative sign in the phase shift equation. Key insights include the importance of multiplying the numerator and denominator by the complex conjugate to clarify both magnitude and phase angle. Resources such as Khan Academy are recommended for further clarification.

PREREQUISITES
  • Understanding of transfer functions in control systems
  • Familiarity with complex numbers and their properties
  • Knowledge of magnitude and phase shift calculations
  • Basic skills in manipulating mathematical equations
NEXT STEPS
  • Study the process of calculating magnitude from complex numbers in transfer functions
  • Learn about phase shift calculations in control systems
  • Explore the use of complex conjugates in simplifying expressions
  • Review Khan Academy's resources on complex analysis for deeper insights
USEFUL FOR

Students and professionals in engineering, particularly those studying control systems, electrical engineering, or anyone seeking to deepen their understanding of transfer functions and complex number manipulation.

wellmoisturizedfrog
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TL;DR
I am unsure if my current understanding of transfer functions is correct.
Hello,

My textbook offers the following transfer function as an example.

1701556509480.png


It then goes on to explain that the following equations represent the magnitude and phase shift of the transfer function.

1701556549125.png


However, I am having some difficulty jumping from the first equation to these equations. From my understanding, in order to find the magnitude of the transfer function, the magnitude of the complex number in the denominator is found. I'm not sure if this logic is correct.

I am also unsure about how the equation for the phase shift of the transfer equation has a negative sign in front. I understand the other aspects of it, though.

I would appreciate any clarifications.
 
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Plotting the complex numbers graphically may help you understand why the denomiator is that way.

Multiply numerator and denominator by complex conjugate of denominator should help understand the angle.
 
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scottdave said:
Multiply numerator and denominator by complex conjugate of denominator should help understand the angle.
And the magnitude as well......this is the standard way to manipulate complex numbers.
 
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Ah I see, thank you for the insight! I appreciate the insight and resources.
 
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