A Future of Milk Can Antennas
Staring from a balcony at Kigali’s IT hub kLab, Bonaventure Karibo thoughtfully points at a series of antennas perched on the roof of a nearby building and says, “You see that antenna? That should cost just five dollars (3,500 RWF).”
The recent Master’s graduate of Rwanda’s Carnegie Mellon University (CMU) believes that because there is an expectation for electronics "that are clean and look good," companies in Rwanda typically purchase antenna’s that are built abroad costing hundreds, if not thousands, of dollars. However, Bonaventure says, “even with a few simple parts and local materials that you can find in normal life you can make an antenna.”
To prove his point, Bonaventure led a team of Carnegie Mellon University students in building by hand, with materials costing a few dollars, an antenna that can project a wireless network over several kilometers.
What materials are needed to enable an aspiring engineer to construct a device capable of transmitting billions of digital bytes through the equivalent of several football fields of thin air? Well, it turns out construction costs can be dramatically reduced if you and your colleagues are milk drinkers. When asked for the total price of building an antenna Bonaventure purses his lips thoughtfully, then admits that, “We never need to actually buy milk cans” as there is always an empty one lying about. While you would think this would be an insignificant cost of the antenna that the CMU students built, the opposite is in fact true: it is the most critical raw component. The only additional materials necessary are some bits of wire and a metal SMA coaxial connector, purchased for a few dollars since for the moment it has to be imported.
How is it possible to make an antenna with just a milk can and some bits and pieces of wire? Very easily, according to Bonaventure. With a self proclaimed passion for innovation, Bonaventure states that, “It’s all about the physics,” in making an antenna work. However, being a part of the Carnegie Mellon University’s inaugural graduation class surely does no harm. One can’t help but think, as Bonaventure talks about the ‘simplicity’ of mono verses omnidirectional radiation antennas, that a Master’s of Science and Information Technology (MSIT) from one of the most intensive centers of learning in Africa surely comes in handy when deciding to manufacture your own WiFi receiver. CMU in Rwanda was conceived by the African heads of state at the 2007 Africa Connect Conference to be the first Information and Communication Technology (ICT) Center of Excellence on the continent, where students could achieve a world-class education while being culturally immersed in what is now the world’s fastest growing continent economically.
Bonaventure and the students he led, under the supervision of Professor Tim Brown, were able to put their money (or their milk cans) where their mouth is and actually use their noticeably handcrafted antenna to transmit a WiFi signal capable of sharing data at a distance of 2.4 kilometers. While this is a huge distance, Bonaventure and his team have already attempted an even more ambitious version with a predicted range approaching 5 kilometers.
The applications of these specific style of antennas are intriguing, with perhaps clusters of home made antennas acting as affordable last mile internet solutions across the continent, but what Bonaventure’s inventive thinking shows more powerfully is that the ability to design local solutions to Africa’s high-tech needs may not be the impossibility that it seems at first glance. As Bonaventure says himself, “The antenna project made me feel that we Rwandese should be pushing more to innovate for ourselves. Countries like China and Japan began by just making things for themselves. We can do that too.”
CMU in Rwanda
MSIT Program in Rwanda