The performance of high frequency electronic devices can be greatly affected by the materials from which they are constructed. Such devices may be found in products such as cellular telephones, radars, wireless routers, microwave data links, and many others. An important focus of this research project was on the creation of so-called artificial electromagnetic materials that have useful properties that cannot be found in naturally occurring materials. Further, we wished to create useful materials that have properties that we can first specify, then create them accurately in the laboratory for use in devices to enhance their performance (see attached image).

Such a capability was achieved in this research. We made a number of discoveries and contributions to science and engineering based on this NSF-funded research project. For one, we created a new type of artificial electromagnetic material based on what we call a “dumbbell” particle (see attached image). This new type of electromagnetic material is able to achieve designable electromagnetic properties with very large values, without suffering from large losses (which would greatly diminish the usefulness of these artificial materials in devices). We also mathematically refined and extended a famous method for calculating these electromagnetic material properties from accurate computer simulations.

One device that we found can be greatly aided by such artificial materials is an antenna called a resonant cavity antenna (RCA).  The RCA is a class of high-gain antennas, i.e., it is capable of directing the beam towards a desired direction.  Unlike most other classes of high-gain antennas, such as the parabolic dish, the RCA is flat and contains minimum mechanical complexity; so, it is much less expensive. Unfortunately, a big problem with such an antenna is its frequency bandwidth, which limits the rate at which data can be sent and received by such antennas.  Generally, a higher gain RCA operates over a narrower frequency band. Many high-gain applications require minimum useful bandwidths that a traditional RCA doesn’t deliver. Our research provided several approaches to overcome the bandwidth problem and develop more practical RCAs. In fact, the best antenna performance was obtained with a round superstrate that is quite puck like, so, we named this practical version of the RCA the “puck antenna” (see attached image). The performance of a puck antenna that we designed and built from commercial materials was four times that of the traditional RCA and, yet, much smaller.

Also, through this NSF-funded project, we were able to create hands-on learning opportunities for high-school aged students and Native American students. A “Buffalo Antennas” summer camp mini-course was created at our university to give high-school aged students an opportunity to learn about the fascinating world of electromagnetics. Two activities were created for different groups of students, and both involved hands-on laboratory experiences including antenna design and fabrication, soldering, and culminating with the students measuring their own antenna performance.

The first activity involved Native American high school girls (see attached image) and was conducted as part of the SD GEAR UP program, which is a program that helps students be successful in a college setting. This program is operated in collaboration with many schools and represents all nine tribes in South Dakota:  Cheyenne River, Crow Creek, Flandreau-Santee, Lower Brule, Oglala, Rosebud, Sisseton-Wahpeton Oyate, Standing Rock, and Yankton. This program boasts some very impressive statistics: of those students who graduate from these programs, virtually 100% also graduate from high school, 85% attend college, while 7% of them join the military. 

The second activity involved high sc...

Please report errors in award information by writing to: awardsearch@nsf.gov.