Two weeks ago my local section of the IEEE coordinated the wireless portion of a Science Olympiad competition. Science Olympiad is a competitive event for high school students. The object of the wireless portion is to build the highest gain 2.4GHz antenna.
Many of the antennas involved a driven element inside a can. One antenna had director elements made of copper tape inside a can.
Another student built a fractal antenna. It did not work very well. When we put it on the vector network analyzer, we found it had an intermittent open in the connector, which we were not able to repair at the event. It would be interesting to see how it works with the connection problem fixed.
Two teams accidentally used reverse-polarity SMA connectors instead of the standard SMAs. Reverse-polarity connectors were created to discourage users from exceeding the EIRP limits by connecting high-gain antennas to high-power transmitters. Reverse polarity connectors are now almost as common as the standard polarity connectors, frequently leading to confusion. Fortunately my colleague Robb Peebles of LS Research was on hand to improvise connectors, in one case using aluminum foil, so all students who used the wrong connector type were able to participate.
It is difficult to measure an antenna’s gain without an anechoic chamber. Constructive and destructive interference of reflected radio waves results in signal strengths varying wildly over very short distances. The test that the event currently uses does not address this multipath fading. The procedure allows students to pick three distances at which their antennas are measured. Knowing fading will be an issue, some students request one of their measurement be at a very large distance. On the off chance the location they pick turns out to be a point with constructive interference, the formula will reward them with more points. They rightly work the random element of multipath fading to their advantage. There are ways to mitigate multipath fading that I hope to see adopted at the event next year.
By chance I met a teacher and Science Olympiad coach from a school district an hour south of me. He explained that the similarities between Science Olympiad and athletic competitions helps generate support for Science Olympiad funding. Still, the school allocates several times more money to athletic than to academic competitions.
Support for academic competitions will hopefully grow over a time. Many teenagers around the world know they need to know science and technology if they want to earn an affluent lifestyle. Students who think an affluent lifestyle is a birthright will be disappointed as the world continues to globalize.
The students I met at the event had great enthusiasm for technology. They asked me and my colleagues why their antennas performed as they did and how to do better at the next event. I think of students like these when I hear dire predictions about how the world economy could be devastated by politicians’ and bankers’ bad decisions. No matter how much taxes and inflation fluctuate, these students will be creating the stuff that drives the economy.