Friday, March 7, 2014
Antenna Tech Comes of Age
In the final days of 2013, efforts to boost broadband connectivity onboard Air Transport (AT) and business aircraft got a big push with the launch of the first Inmarsat Global Xpress (GX) satellite and JetBlue’s Fly-Fi service. These two events, signaling the entry of Ka-band services into the AT market, topped off a year of growth and innovation in service and technology offerings for an industry straining to supply enough bandwidth to meet surging user requirements. One of the hidden keys that is making the innovative service possible is the humble antenna, now more capable and lower profile.
The demand for continuous access to higher quality connectivity is coming mainly from the cabin, where passengers increasingly “expect to have an experience that mimics the Internet in their home or office,” says Jack Jacobs, vice president of marketing & product management at Honeywell. A recent survey of 3,000 adult fliers conducted by Honeywell in the U.K., U.S. and Singapore lent support to these views, finding that “more than three in four fliers … think wireless access should always be available on planes.”
JetBlue’s Fly-Fi is just one small evidence of how much the market has taken notice. For example, the number of commercial aircraft with wireless Wi-Fi or cellular phone connections, pegged at 4,048 or 21 percent of the global fleet, at the end of 2013 is projected to increase to 14,000 aircraft, or about 50 percent of the fleet by 2022, according to research firm IHS.
That growth track is sparking competition among industry vendors to introduce faster and more efficient offerings. Last December, JetBlue tapped into the higher speed Ka-band with the launch of its Fly-Fi in-flight Wi-Fi service onboard three of its Airbus A320s. The U.S. airline uses ViaSat’s new Exede product that delivers 12 Mbps per device, regardless of the number of passengers using the service, says Lance Diamond, director of business development at ViaSat.
After launching the Inmarsat-5 F1, the first of the three GX satellites, Inmarsat is on track to provide by the end of 2014 “seamless global Ka-band coverage [and] … consistent higher performance of up to 50 Mbps to mobile or fixed terminals,” according to the company, which tapped Honeywell to develop, produce and distribute the onboard hardware enabling users to connect to new networks. The hardware is to include a steerable directional antenna system mounted outside of the skin; subcontractors including Thales Alenia Space and Qest are slated to help integrate the avionics and antenna systems, and provide the apertures.
Inmarsat has also signed with Redmond, Wash.-based Kymeta, a 2012 startup company that has drawn support from high profile investors including Microsoft founder Bill Gates, to develop very low profile antennas for business jets using the GX aviation service. A radical departure from existing designs, Kymeta’s Aero Antenna “has no moving parts,” says Håkan Olsson, the company’s senior director of marketing. It utilizes an electronically steered beam that orients towards the satellite using its antenna surface made of metamaterials, or synthetic materials with properties not found in nature, as Olsson explains. These metamaterials can manipulate incoming electro-magnetic radiation such as light or radio waves to redirect it in a variety of potentially useful ways, says Olsson, and the Aero Antenna is just one use.
In practical terms, the use of metamaterials in place of moving parts allows the device to be flat and thin, and when it’s mounted on the aircraft surface, the module including receiving (RX) and transmitting (TX) panels is only 20 x 20 inches wide and about 2 inches high. By comparison, medium profile Ka-band antennas with radomes can be as much as 12 inches high, or more.
“The low profile … results in lower drag compared to a mechanically steered antenna, which ultimately means lower fuel consumption,” says Olsson. “The flat design … enables smaller aircraft to be equipped with high speed Internet connectivity where traditional solutions are either too large or too expensive.”
Also, because it has no moving parts, the device has much lower maintenance costs and also consumes less power than traditional phased array antennas, requiring only a few watts of power to operate.
Kymeta plans to deliver the antenna to Inmarsat in early 2015, according to Olsson. Looking forward, “a key challenge to commercializing the Aero Antenna is to focus on the right opportunities as Kymeta has received an overwhelmingly positive response to its technology with many requests for solutions across many different kind of aviation applications.”
Innovation isn’t confined to the Ka-band. Gogo is set to launch this year its Ground to Orbit (GTO) hybrid Ku-band and Air to Ground (ATG) systems that will offer speeds of 70 Mbps and up to aircraft flying throughout North America, says Anand Chari, Gogo’s senior vice president of engineering and chief technology officer.
GTO is “all about lower profile antennas,” Chari says. That lower profile comes from using a smaller receive only Ku-band along with its latest ATG offering ATG-4. “The [Ku] antenna also can be positioned to lie in a much flatter position on the aircraft and is roughly half the height of typical aero antenna/radome, which results in much less drag/fuel burn,” he says. “Gogo’s satellite antenna can use a number of today’s … and future Ku-band satellites including spot beam Ku satellites.”
Chari lists a number of advantages to the technology, from using satellite for reception and ATG-4 for the return link. He notes that since Gogo’s antenna is receive only and won’t interfere with other satellites, it is more efficient than two-way antennas that must limit their transmissions to avoid such interference. In addition he claims that the ATG offers the best return link from aircraft with low latency.
Of course, Gogo’s offering, now used on more than 2,000 commercial aircraft, has coverage limitations since it relies on ground-based infrastructure, but the company is addressing that shortfall by signing on to use Global Xpress and Ku-band service. “Gogo has always positioned [itself] … as a technology neutral company, meaning that we offer a variety of different solutions to our customers,” said Chari. “Despite what many of our competitors claim, we don’t see a one-size fits all solution; what’s best for a 787 flying overseas is not the same as what you might use for a regional jet flying from Des Moines, Iowa, to Chicago.”
With the addition of these offerings, Original Equipment Manufacturers (OEMs) and operators can choose from a variety of broadband solutions, including Ku- and Ka-band, Inmartsat’s Swiftbroadband L-band and ATG options.
With all these choices, “I think the focus has moved away from technology and more towards service,” said Alan Hnatiw, SATCOM antenna program manager at Esterline CMC Electronics. “Each technology has demonstrated that it can fulfill a niche,” and operators must determine “what they want to offer and how much they can charge the end user … [for a] particular capability,” and what their customers want or are willing to pay for.
|Gogo’s newest GTO technology. Courtesy of Gogo.|
In the midst of these broadband wars is a growing divide between services offered in the cabin and cockpit. “We participated actively in the ARINC 781 Attachment 8 Workgroup together with the major aircraft manufacturers … [and] were impressed with the result, which defines data security and segregation requirements for the Inmarsat SBB Safety Services provision,” Gram says. “Our read of the situation is a clear direction to keep all aircraft professional communication on L-band services due to the robustness of the frequency band combined with … [its ability to] secure the professional aircraft domains against data infringements from the outside.”
In fact, two separate satellite communication systems are becoming the standard now, says Hnatiw. Dedicated high data rate solutions using large Ku/Ka antennas for the cabin are now employing non-safety certified networks and high reliability safety certified equipment and networks to meet the application requirements for the cockpit, he says.
“Cockpit applications do not require the high data rate offered in the cabin, but solutions using Swiftbroadband and Intermediate Gain antennas, such as the Esterline CMC Electronics CMA-2200SB, can still offer mega-bit class performance with an antenna weighing approximately 6 pounds.”
To address this segregated market, Cobham will begin rolling out its Aviator S series antennas in 2015, which will offer a range of systems offering single channel and multichannel systems, designed with the data segregation architectures in a two box form factor that is slated to make IP data connectivity a realistic provision on all types of aircraft.