By Casia McLeod
AlbertaSat’s very own, John Grey, has been selected as a top 6 finalist in the 8th IEEE Antennas and Propagation Society (AP-S) Antenna Design Contest.
Applicants were asked to design and build an antenna, with a budget of $1500, for a CubeSat that enables high-performance communications with a ground station. The finalists receive necessary travel funds to attend the IEE Antennas and Propagation Symposium in San Diego, California on July 9-15, 2017 where they can demonstrate their working systems. From the 6 teams, 1st, 2nd, and 3rd place are announced at the 2017 IEEE AP-S Awards Banquet at the conference, the top 3 winners will receive cash awards. From there, the final reports will have the opportunity to be considered for publication in the IEEE AP Magazine.
The design contest was very intriguing to John, as one of the largest constraining factors on the Ex-Alta 1 mission has been power production.
“On the last satellite I was in charge of power management, so I understood how bad the situation was in the satellite with regards to the power generation and I knew how much power the radio system used, so trying to reduce that while simultaneously increasing power was really important.”
John is working on the project with Ph.D. student, Thomas Jones. John and Thomas, applied to the design contest in December 2016 and had spent the semester before that preparing and planning their proposal. Thomas Jones works for Mojgan Daneshmand’s M2M lab. By March 31st they are required to have designed and tested the antenna and will then present it at the Symposium in early July. The hope with this project is that AlbertaSat will be able to use it alongside open source hardware, developed here at the U of A, for the transmitter portion of it. This is the load that goes on the end of the transmitter so ideally, there will be a whole AlbertaSat open source radio system to go on the next satellite. John and Thomas’ design is helping AlbertaSat work towards that goal.
“The concept is that satellite power generation is difficult on a cubesat, we don’t have a large surface area for a lot of solar cells, in a best case orbit we’re going to produce roughly 10 W of power and in worst case, roughly 2.3 watts of power. And these values, we’re going to lose a lot of it to efficiencies and electrical power systems beforehand. We’re looking for any way we can increase the power brought into the satellite. This is made even harder cause the satellite now must use a higher frequency radio transmission system and this makes it so that as the frequency goes up, more power is needed. Compared to Ex-Alta 1, we’ll be having even higher power use requirements.”
Something very unique about their design is that it will be combining two traditionally distinct systems. They are designing an antenna integrated into the solar panels of a cubesat. Their design allows for a directional antenna system to be integrated into a cubesat without reducing the area available for solar cells.
By only illuminating the Earth, and not radiating into space, the antenna will require less than a quarter of the power compared to the omnidirectional antenna on Ex-Alta 1. Also, the satellite will not see a drop-in power production, since no solar cells need to be removed to accommodate the antenna. Also, because the antenna is directional, it will only be operational once the satellite is stabilized. The antenna is designed to operate in the 2200 MHz or 2300 MHz range, which is allocated for space-ground communication.
The hope is that AlbertaSat will be able to use the antenna on our cubesat. It would take up 2U’s of the side face and would hopefully interface with the open source structure that AlbertaSat member, Corbin Cooper, designed.
John’s work will open many doors for AlbertaSat and will even help the group financially. This design contest will not only enhance Ex-Alta 2’s power generation, but it will also help bring recognition to the hard work and dedication that AlbertaSat members, like John Grey, bring to our team. We are proud to see our members reaching for the stars. John and Thomas, we wish you the best of luck in San Diego.