Senior Design Story
Pete Weber recently completed his senior design project under the supervision of Dr. Mohammad R. Zunoubi. Although it is an electrical engineering project, it has no wires, chips, black boxes or moving parts. In fact, it basically consists of a few thin strips of copper laid down on a thin board. But these strips, hooked up to a microwave signal, will filter out all electromagnetic signals except those whose frequencies fall in a narrow predetermined band. Using other methods would require many precisely determined physical devices like capacitors and inductors or, if done digitally, complex processors and specialized programming techniques.
“I was thinking that I wanted to design some kind of electronic filter,” says Pete. “Then I sat in on a senior design presentation by Barry Treloar and Kip Kostenbauder. They had designed a microwave filter, but the thing basically looked like a big rectangular pipe with a few screws in it, and in fact, that's what it was. Pure geometry was accomplishing this complex and important engineering task – there was something mysterious about it. Of course you don't get something for nothing. The theory behind all this stuff is formidable. But when I realized that similar physical processing of microwaves can occur on the microchip level as well – that there were actually integrated circuits with all these tiny tunnels and alleys shuttling electromagnetic waves around - I knew I wanted to do something related for my senior project.”
Pete's project, rather than taking “pipe” form, was constructed of “microstrip”, which is more closely related to what would be used in an integrated circuit. Years of research has resulted in sophisticated theory, design equations and techniques for making all types of microwave filters in many forms. A special milling machine in the microwave lab was particularly suited to the construction of Pete's final design.
“Personally, I wish I had finished my project a semester early; then I would have spent my last semester just playing around with designs, software and that milling machine, making and testing different microwave circuits. And I highly recommend that any student who even suspects he/she might be interested, take the Microwaves course when they offer it. You might be worried that it's an extension of the Electromagnetics courses you are so glad you don't have to take again, but it's not - and a whole new world of engineering might open up.”