Abstract: Modern wireless telecommunication requires high linearity of radiofrequency amplifiers.Feedforward technique is the most effective and sometimes the only one that can improve the linearity to satisfy the system demands.It improves the linearity of an amplifier through the following three steps,extracting the nonlinear distorted component from the output of the amplifier,adjusting the amplitude and phase of this nonlinear distorted component to obtain the same amplitude and opposite phase as the distorted component of the amplifier output,and counteracting the distorted component by summing up the adjusted nonlinear distorted component and the amplifier output.ADS is one of the most popular software for radiofrequency circuitry design.Its simulation results can reflect the characteristics of circuits correctly.In this paper,we elaborate the basic theories and methods of feedforward technique.Then we simulate a feedforward amplifier by using ADS software.The simulation shows that the third-order intermodulation component has been improved by more than 40 dB.The result of the present study suggests that the effectivity of the feedforward technique improves the linearity of amplifiers.