Discuss the perfFrequency response is the steady-state response of a system to a sinusoidal input. In frequency-response methods, we vary the frequency of the input signal over a certain range and study the resulting response. - The design of feedback control systems in industry is probably accomplished using frequency-response methods more often than any other, primarily because it provides good designs in the face of uncertainty in the plant model.ormance specifications in the frequency domain and relative stability based on gain and phase margins. Include a consideration of how frequency response methods contribute to meeting desired specifications