Stone Knives and Bearskins
RF design has clearly come a long way over the past 30 years that I have been involved in one way or another. Unfortunately, it’s never been as sexy as computers and integrated circuits, so by and large, even the engineering community is not aware of the progress and innovation. Outside the engineering community, near total ignorance exists among most people. It’s amazing to me how few people realize there is a radio inside their “wireless cellular phone”! I’m not sure what they associate the term “wireless” with, but it’s certainly not like the old WW I and WW II movies where they “fire up the wireless.
” To me, the two greatest innovations in RF have been the development and deployment of the cellular telephone network and the tremendous power of RF simulation. Interestingly, neither is a very new idea.
Cellular phones, of course, can trace their germination all the way back to Marconi himself. But, the real concept sprouted in the 1940s when mobile telephones first appeared. The concept of frequency re-use with low-power cells was conceived in 1947 by Ring and Young of Bell Labs (thank you Wikipedia!). Essentially, it was the same concept that is used today.
Simulation is similar. The mathematics to describe the functions of RF and travelling waves were developed many decades ago. Engineers fiddled with their slide rules to predict behavior and did so with surprising accuracy given their tools were “equipment that is hardly far ahead of stone knives and bearskins”, to quote one of my favorite characters in literature: Mr. Spock.
What was necessary to make either concept a practical reality was that shapely sexpot: the computer. And, not just “a” computer, like the ENIAC — filling a room, but one orders of magnitude faster, with orders of magnitude more memory, and infinitely smaller. I honestly believe that the folks who designed ENIAC truly never imagined computers as powerful, containing as much memory, or as small as what we have today.
So there is that conundrum again… the computer is the essential and sexy component of even the most advanced RF systems! But what systems those are!
At Mentor Graphics, our flagship simulation products are HyperLynx and IE3D. These simulators allow multi-billions of iterations to accurately predict high-speed digital and high-frequency (to tens of GHz) RF circuit behavior. Even more important, designs can be changed and re-simulated in the blink of an eye (well…almost). Designers now have the freedom to optimize their designs, account for real-world issues and influences, and by the time the product goes to manufacturing, darn near all the possible problems have been diligently accounted for and eliminated.
It kind of reminds me of a nickname that the computer center technician gave me and a couple of buddies way back when. He would look up and say “Here comes the trial-and-error programming crew!”
If he had only realized how far ahead of our time we were!
* Mark Forbes is Content Manager for Mentor Graphics Corporation with more than years in electronic design, antenna design, product marketing, and documentation. Mark has patents in antenna design and digital communications, and is the inventor of the Ventenna, a concealed antenna system. He has a BSEE from Bradley University in Peoria, Illinois.