In frequency response analysis the input to the control system is fed with a sinusoidal signal with different frequencies. The output from the (LTI) Linear Time Invariant system will be of same sinusoidal signal with same input frequency but variation in the magnitude and phase.

Hence the change in the magnitude of the input signal and phase for wide band of input frequencies are determined in Frequency Domain Analysis

**Advantages:**

Some of the advantages of frequency domain analysis are:

- Transfer functions which are complicated to determine the behavior of the experimentally can be determined using the frequency response analysis
- Design of the system and adjusting the parameters of the system can be easily carried out.
- Corrective measurement for noise disturbance generated in the system and parameters variation can be easily determined using frequency analysis
- Absolute and Relative stability of the closed loop system can be estimated from the knowledge of the open loop frequency system
- Frequency domain analysis can also be carried out for the non linear control systems.