Personal computers, and the software within them, have changed the world. Much can be said about the "wireless revolution," and the tremendous convenience of being able to reach anyone with a cellular telephone. But in the last several decades, it has been the PC that has had the greatest impact of any electronic device on most lives. It is the operating system and application software that defines the functionality of the PC. And in this industry, computer-aided-engineering (CAE) software is a tool of choice for most designers, replacing the trusty slide rule.

Microwave software developers have taken full advantage of the processing power. With today's multicore processors, PCs have many times the power of even workstations of a decade earlier. That processing power allows electromagnetic (EM) simulators, for example, to divide complex analytical problems into parts to be solved separately, and then combined to reach a final answer.

Still, for all the analytic power contained in modern microwave CAE programs, there is always a risk of relying too much on tools and not enough on skills. For writers, learning to spell words correctly is one of the skills of the craft. A computer spell-checker can do it for them, but it can't teach them to spell.

Similarly, depending on microwave CAE software to optimize a design is not necessarily learning how to design. True, a great deal can be learned by taking note of what changes take place in a design from one iteration to the next as the CAE program's optimizer takes steps to enhance performance. But, as one of the authors in this issue points out (see Zelman Harbater and his advice on designing waveguide tapers on p. 51), a design must be close before it can be optimizedthe computer can't do all of the work.

Using an EM simulator can provide tremendous insight into the fields around a high-frequency circuit or structure. Properly used, an EM simulator, or circuit simulator, or system simulator, can help an RF engineer dramatically improve the performance of a design. But to truly understand why the performance has improved, that engineer should go back to Maxwell's equations and develop an appreciation for their elegance and how Maxwell was able to capture the physics of natural phenomena, the propagation and radiation of electric and magnetic fields, into the symbolically beautiful language of mathematics. As Zelman Harbater explains in his article, understanding the design equations at the heart of microwave CAE simulators, rather than just using the simulator, is a major step toward becoming a better engineer.