Frequency response analyzer is a critical tool in evaluating control systems. It involves the application of a range of pure sinusoidal inputs with different frequencies (or frequency components) and the study of the output response characteristics as a function of the input signal frequencies. The advantages of this method are in its ability to determine the stability and give information about the behavior of systems at frequencies diverse from the standard DC level. Just like gain and phase response analysis helps in identifying the problems and solutions, this frequency analysis allows for striking out the effective problems as well as begins to indicate the solutions by proposing the optimum gain/phase plot as shown below. This analytical approach helps in planning and optimising various contexts of control system in electronics, automotive, defence, and aerospace industries.