Simulating complex circuits with an electromagnetic (EM) simulator can require time and computing power, especially for a design as complex as a recently developed millimeter-wave frequency converter from Mimix Broadband. Fortunately, the firm was able to rely on the AXIEM software from AWR on a desktop personal computer (PC) to study the entire structure of the device, including innovative passive circuits, and reduce the overall size of the chip without compromising performance design goals. The design involved more than 100 ports and 100,000 unknowns. In addition to validating the performance of the chip, the designers learned a great deal more about the circuit's physics as well. The complete success story is available on the AWR Corporation web site.