In an era of evolving high-speed Internet satellite communications and the rugged domed antennas that make connectivity reliable in the middle of the ocean, it’s interesting that flat panel antennas (aka phased array antennas) for SATCOM are being introduced for sale to the leisure marine market this year.
“Going Domeless”, an article in the May/June 2017 issue of Marine Electronics Journal, offers a look at one approach to marine flat panel systems. As a pioneer in the use of mobile flat panel antennas for satellite television, KVH was asked to weigh in on this new technology and its practicality for marine applications, a response we’re pleased to share below.
KVH: Marine conditions favor dome antennas
(May 1, 2017 – republished courtesy Marine Electronics Journal)
KVH is a major manufacturer of traditional stabilized marine antennas, both satcom and TV. We asked them to comment on flat-panel antennas. Here’s what Rick Driscoll, VP Satellite Products & Services, told us:
Most of the press describing use of flat-panel antennas revolves around two-way satellite communications, or VSAT. One reason for this is that generally TVRO services require simultaneous reception of wide bandwidths (typically a GHz or more) and simultaneous dual polarity. This simultaneous reception is difficult to realize in dynamically scanning flat-panel designs.
Kymeta is very interesting technology, and there may be applications that lend themselves to their design approach and constraints. However, we don’t feel Kymeta will have universal applicability, particularly in applications with low elevation angles, highly dynamic environments (like maritime) and/or applications where wide bandwidth and simultaneous reception and/or transmission are required. If the “hybrid” approach (mentioned in the article) involves mechanically moving or tilting the flat-panel antenna, then it would defeat much of the purpose of the flat panel.
Pitching and rolling are problems
The biggest difference between flat-panel/phased-array antennas and reflector-based/dome antennas in the maritime market is that flat-panel antennas don’t perform as well on a boat that may be pitching, rolling, or cruising in northern latitudes. The reason has more to do with geometry than with the antenna technology itself. With a flat-panel antenna, you will get a weaker signal when the panel isn’t fully perpendicular to the satellite, which can happen quite often at sea depending on boat location and motion.
Having been a pioneer in flat-panel technology when we introduced a phased-array satellite television antenna more than 10 years ago, KVH remains excited about the potential of low-cost, high-performance flat-panel antennas to provide better experiences for our customers in suitable applications. We still make a phased-array satellite television antenna for the automotive market—it’s called the TracVision A9. For the maritime market, our engineers have always found that our reflector-based/dome antennas are better suited (TracVision TV-series and HD-series for satellite television; TracPhone V-IP series for satellite communications) than flat panel as there are many issues created by boats pitching and rolling that make phased-array signals weaker in that application.
Buyers: ask questions
With flat-panel antennas, captains and boat owners should be sure they ask about elevation range and how their vessel’s location and motion will affect the phased-array antenna’s performance; they need to ensure the phased-array antenna will be compatible with the satellite service provider’s bandwidth; and they need to really think through the issue of having several phased-array antennas on the boat to do the same work that one dome antenna has proven it can do for years.