There are many design steps required for the development and manufacture of MMIC circuits, as illustrated in the MMIC Design Flow. Advanced Design System (ADS) is a central part of the complete MMIC design flow, and is used throughout this process. This application note illustrates, through the design of an MMIC amplifier, several of the common problems faced in designing, simulating, and producing a physical layout of an MMIC circuit, as well as the validation steps that are needed to verify that the physical layout still produces the desired result.