New electronically steered and phased array antennas are entering the market as the demand for higher data rates and the expected debut of Low Earth Orbit (LEO) satcom set the stage for innovation.
Antennas and satellite terminals are being developed to serve business jet passengers that are smaller, lighter and consist of fewer line replaceable units (LRUs). One thing these new antennas can do is connect to LEO constellations.
Opinions differ on how much LEO might do for business aviation.
Steve Newell, chief commercial officer for Satcom startup company NXTCOMM, said LEO satellite services can do it all in business aviation. “LEO will allow for smaller antennas and lower cost of installation on the middle of the fuselage. LEO connections will provide significantly more bandwidth and reduced latency than geostationary orbit GEO satellites. Once LEO is built out, there won’t be much talk about the viability of (GEO),” he said.
NXTCOMM is in the military market and has not entered the business aviation market yet. Newell was previously chief commercial officer at cabin telephony company TrueNorth Avionics, where he worked with all the large avionics OEMs. TrueNorth is now owned by Satcom Direct.
ThinKom points to other estimates of lower market penetration by LEO. Bill Milroy, ThinKom’s CTO, notes that Northern Sky Research (NSR) forecasts that, by 2030, only 20% of inflight communications (IFC) will be carried over non geostationary orbit (N-GSO) satellites. This includes LEO and medium earth orbit (MEO) satellites while 80 percent will remain with geosynchronous (GSO) platforms. NSR is a market research firm focused on satellites and space. ThinKom isn’t sure how the market will develop so it is hedging its bets to make sure its antenna solutions are compatible with both GSO and NGSO constellations.
Viasat’s senior director of business for Business Aviation, James Person, said his company’s trio of third generation GEO satellites will have 1,000 gigabits per second of capacity each. Called ViaSat-3, the new GEO satellite constellation is flexible, in that it can automatically direct a lot of that capacity to the East Coast as business jets fire up their engines in the morning and then shift the bulk of it to California when the same thing happens three hours later in the morning there. LEO satellite networks can’t do that as their capacity is evenly distributed throughout the globe, which is not how aviation traffic - or any other usage – is arranged. Eventually, Viasat plans to launch a small number of non-GEO satellites to cover lightly travelled polar routes, which GEOs can’t currently service.
Thinkom’s new Ka1717 mechanical phased array antenna is designed in partnership with CarlisleIT to fit on a regional jet as small as a CRJ 200. The Ka1717 has two 17 inch (active diameter) antennas, one for transmit and the other for receive. Regional jet aircraft haven’t had access to a level of connectivity service comparable to mainline narrow and wide body airline fleets.
The Ka1717 will eventually be offered for use on large business jets. Milroy said it will work well connecting to LEO, MEO, GEO and highly elliptical orbit (HEO) satellites.
Milroy notes that Telesat of Canada indicates its LEO satellites will provide downloads at 600 megabits per second (mbps) and uploads of 200 mbps per aircraft with the Ka1717 antenna. “We can do these pretty crazy data rates,” Milroy said. These rates compare to a typically lower rates from GEO satellites of 60 to 100 mbps download and 10 to 20 mbps upload.
Milroy said a mechanical phased array like the Ka1717 provides four times the performance of an active electronically scanned array (AESA) of the same size. It’s six inch high complete antenna subsystem weighs 160 pounds (250 pounds installed) and consumes and dissipates a very low amount of power.
Starlink is another LEO satellite constellation. Starlink connections have been tested on Gulfstream jets and U.S. military aircraft and by Musk on his private jet. Space X has launched more than 3,000 Starlink satellites into low earth orbit with 1,400 yet to come.
JSX, an operator of 10 Embraer 135 and 145 aircraft on scheduled service from private terminals in the Western U.S. and between New York and Florida, plans to use Starlink for inflight Wi-Fi later this year. Milroy said one caveat for business jet operators is that there is no Starlink system or a service level agreement. If service is spotty you may just “get what you get,” he said.
The technology is moving on from tail mounted antennas to flat phased array and actively scanned electronic array antennas on the fuselage that are “suited to smaller aircraft,” said David Grice Manager, Business Development for Carlisle Interconnect Technologies. Most of the antenna systems that CarlisleIT develops installation kits for are for super midsize jets all the way up to VIP airline aircraft.
CarlisleIT also works with antenna OEM’s to design, package, and qualify antennas, and develops passive thermal management systems for phased array and AESA antennas which generate a lot of heat. These antenna systems have to be able to function while the jet is on the ground on a hot day.
While antennas used in commercial aviation are coming down in size, the need to handle more data than is currently possible with tail mounted antennas in the business aviation world is driving the development of larger antennas for these platforms. At the same time controllers, amplifiers and modems are all being integrated into the antenna to reduce the LRU count and installation complexity. Grice said he expects there to be some antenna announcements at NBAA this year.
Grice says the way forward in business aviation antennas is to follow what the airlines did a few years ago and develop standards so a universal type satcom antenna can work for every aircraft type to avoid the cost of customization. “Then retrofit will become a lot easier,” he said.
The agile electronic antennas will be needed to handle LEO connections, according to Grice. At cruising speed multibeam AESAs will be able to keep contact with one LEO satellite and lock on to another, while keeping in touch with the first one until the transfer is compete. Antennas will need to do this every 6 minutes or so to ensure uninterrupted LEO service to the passenger.
Satcom Direct has been providing Satcom services for private aviation for 25 years and provides software as a service and hardware including satcom terminals. It is now developing a new antenna series named Plane Simple. This series, with fewer LRUs, means there is less wiring required and a less intrusive installation for both forward fit and retrofit.
Plane Simple is a three-antenna product line which will have two tail mounted antennas, one for Ka-band and one for Ku-band, plus a Ku-band electronically steered antenna. The product line will be rolled out in private jets over the next two years, according to Michael Skou Christensen, chief commercial officer for Satcom Direct.
This tail mounted Ku-band antenna is designed to work with the Intelsat FlexExec service and will enter service in October. The company will be flight testing the Ka-band tail mounted antenna later this year for entry into service early next year. It is designed to work with the Inmarsat Jet ConneX service. Finally, the electronically steered Ku-band antenna, designed to be mounted on the fuselage of a business jet, will be tested in 2023 and enter service in 2024. It will connect to the OneWeb LEO service.
Satcom Direct is aiming for a system versatile enough to adapt to new technology during the lifetime of the aircraft in service with the original customer. This is because technology is changing faster than the 5 to 10 years of private jet ownership. A modular system allows upgrades as technology changes by swapping out some components rather than installing an entirely new system.