Bruce Elbert, President, Application Technology Strategy, spoke about satellite antenna technology at an Apex educational session.
He said the first full demonstration of broadband access to a satellite was by NASA in 1993.
Elbert added that there are now many lower-profile, high-efficiency antennas coming to market, but are these the future for connectivity services?
He delivered a white paper on the range of antenna options for aircraft with a focus on the latest technologies and their impact on broadband services to passengers.
He said that all operators offering broadband services use geostationary satellites and Boeing introduced its “Connexion by Boeing” (CBB) broadband service 10 years ago using a phased-array antenna.
“There is a technical issue with flat phased-array antennas,” he said. “The problem is that the signals come in at an angle. With a flat panel array you lose half of your signal when that angle comes down to 30 degrees.
“In those days if you flew much higher than 60 degrees latitude you lost the satellite. But you get better performance nearer the equator where the arrival angles are much higher.”
He said Boeing eventually moved to a mechanically-steered antenna to get around the problems of operating at high latitudes, but geostationary satellites don’t work when you get above about 80-85 degrees.
Today, most applications are made via broad-beam satellite, but he added that future spot beam satellites will provide faster, higher-powered connectivity.
Elbert said that adjacent satellites can be interfered with if you don’t control the beam width of your transmission. Near the equator, you can get interference to adjacent satellites with a mechanically-steered antenna (so-called skew angle issues), but with a phased-array antenna this is less prone to happening.
Gogo is due to introduce its new 2Ku antenna, which is a dual-aperture phased array that does away with skew-angle issues.
He concluded by saying the selection of the antenna you use should be based upon your own particular needs. You may need multiple antennas to cope with all your requirements.
If you want to know more about how satellite antennas work you can read our special Get Connected antenna feature.