WASHINGTON — Communications technology firm Harris Corp. of Melbourne, Fla., is ready to sell large, unfurlable Ka-band satellite antennas that will enable greater throughput and more spot beams for commercial satellites, company officials said April 5.
Harris expects satellite manufacturer Space Systems/Loral of Palo Alto, Calif., to order the first 5-meter Ka-band mesh antenna later this year, Bill Gattle, Harris vice president of space communications systems, said in an interview.
For decades the majority of commercial communications satellites have operated at frequencies ranging from L-band starting at around 1 gigahertz to Ku-band frequencies up to about 18 gigahertz. In just the past few years, some of the industry’s biggest players have invested in higher-frequency Ka-band satellites to better support bandwidth-intensive applications such as high-definition television signals. This frequency, however, is more susceptible to foul weather conditions than other more commonly used satellite frequencies.
The migration to higher frequencies will continue as bandwidth requirements grow and the traditional satellite frequencies become even more congested, said Laura Hammer, director of Harris’ space structures division.
“I think it’s because the bandwidth in the other frequencies is getting so crowded, and I think that it’s the consumer’s insatiable demand for more bandwidth with mobile devices, faster and faster Internet speeds, and real-time video demands both in the government arena as well as in the consumer arena,” Hammer said. “We’ve definitely seen a tremendous increase in the number of satellite owners and operators that are planning to put up a Ka-band satellite in the next couple years.”
Harris is one of the leading suppliers of solid reflector antennas for spacecraft and has built more deployable mesh antennas than any other company, Gattle said. The majority of Ka-band satellites ordered to date use small solid dishes, such as those Harris is building for Inmarsat’s three Global Xpress satellites. Harris expects to be first to market with large, unfurlable Ka-band antennas, he said.
Unfurlable mesh antennas provide large apertures that enable greater throughput and the ability to put more spot beams on the ground, Gattle said. Deployable antennas also have less weight and stowed volume and superior thermal and acoustic properties, he said. However, they are more complex to build and therefore more expensive. Harris believes the greater revenue streams these larger antennas would provide will more than make up for the difference in price.
“Unfurlable is slightly more complex to build than a solid,” Gattle said. “So there’s a trade that you’re making for the price. [Operators would be] getting a lot more throughput and capacity, so they’re going to get that back on the revenue side.”
While Harris has never flown an unfurlable Ka-band antenna, it has built 50 antennas with similar radial rib designs in other frequencies that have worked properly on orbit, Gattle said. Harris built the 12-meter S-band reflector on Eutelsat’s W2A satellite that turned out to be defective, but that system was based on a different, more complex design, Gattle said.
Large, unfurlable antennas require a large satellite bus, so they are not an option for smaller communications satellites, Gattle said. Harris estimates there will be two to four of these large commercial Ka-band spacecraft ordered each year, which could each carry two to four unfurlable antennas.
The company is also developing what it calls a fixed mesh reflector, which is in the same smaller size class as solid reflectors but uses a mesh similar to its unfurlable models. Fixed mesh reflectors will have thermal and acoustic properties similar to Harris’ unfurlable antennas and be lighter than solid reflectors, Gattle said.
Harris believes the industry will move toward even higher frequencies in the future that require more sophisticated reflector materials.
“We’re also looking to extend the frequency range of our products by using something called X-mesh, which will get us to even higher frequencies,” Gattle said. “We believe this trend’s going to continue, and people are going to want to get into higher frequency ranges like Q- and V-band over time.”
