Antenna Industry: Tuned to Future of Satellite Communications

The companies that supply transmission systems for use on the ground and aboard spacecraft must continuously innovate as satellite operators strive to meet their users’ growing demand for telecommunications services. Yet even as they overcome daunting technological challenges, antenna companies must also deliver equipment that is more reliable, easier to use, smaller and less expensive than before just to stay competitive.

“We may be small compared with other industries, but we have a huge impact on the world,” says Earth station pioneer Jim Oliver, founder and CEO of AvL Technologies, a satellite antenna firm. “We have to be on the cutting edge all the time.”

The antenna industry’s challenges – and opportunities – are rooted in the continuing quest by satellite operators to find more transmission capacity and deliver better connections to broadcasters, Internet providers, oil-exploration firms and other customers they serve. In the years since the dawn of the satellite industry, when the relatively low-frequency C-band was king, operators have added higher frequency bands to the slices of radio spectrum they use.

After C-band came Ku-band – now a mainstay of satellite communications because of its inherent advantages compared with C-band, such as the ability to use smaller antennas. More recently, the industry has started embracing the even higher Ka-band, which offers very fast connection speeds but poses multiple challenges because a fundamental characteristic of electromagnetic energy: radio waves decrease in length as frequencies go up. Because Ka-band radio waves are shorter than their Ku- and C-band cousins, they require more precise antennas and are more susceptible to interference from atmospheric moisture.

“In all aspects, Ka-band is more difficult than Ku-band and much more difficult than C-band,” says Oliver. “Things are getting harder, but we have to make them easier.”

With multiple satellite operators now either offering or planning Ka-band services, the antenna industry has been investing in the development of systems optimized to operate at high frequencies. Some of the advances in antenna technology have been evolutionary and some revolutionary,” says Jeff Clark, senior director of systems architecture at Intelsat. He points to spot-beam systems, which target signals at defined geographic areas and permit individual frequencies to be used more than once, as an example of an advance in antenna technology that has taken hold across the industry.

 

Key Advances

Some spot beams are steerable, allowing them to be adjusted once a satellite is in orbit. Key advances in the design and capabilities of the satellite-mounted reflectors that move radio waves have also taken place in recent years, Clark says. For example, these components have become less susceptible to the severe temperature extremes in space. This means they won’t change shape as much as previous designs, which results in more reliable transmissions and allows for the use of smaller spot beams, he says.

Improvements in stability have also helped reduce the size of antennas on the ground, says Keith Buckley, CEO of ASC Signal. ASC Signal has developed a sub-reflector tracking system that compensates for the changes in a satellite antenna’s shape that can be caused by variations in air temperature, he says. Left unchecked, these alterations can result in degraded transmissions, particularly at higher frequencies.

The world’s insatiable – and increasing – appetite for connectivity makes tackling the challenges that come with high-frequency transmissions essential for the antenna sector, according to industry officials. “Necessity is the mother of invention, so we find a way” to overcome problems and allow customers to benefit from the capacity and speed these bands offer, says Kent Leka, business area manager for satcom antenna systems at ViaSat.

ViaSat specializes in satellite antenna systems optimized to move large amounts of data efficiently and has played a key role in making Ka-band a viable solution to the satellite industry’s need for transmission capacity.

In addition to developing better ways to handle radio waves, the antenna industry has tapped advances in electronics to produce transmission systems that can handle the complex requirements of higher frequency bands. Smaller circuitry, swifter microprocessors and smarter software have all contributed to the industry’s ability to build antennas that can track satellites with greater precision and tune in radio signals more accurately, according to officials.

 

Host of Benefits

A host of benefits for satellite operators and users alike accompany the challenges that come with using higher frequency bands, says Ali Zarkesh, business development director for satellite communications, Vislink. Whereas C-band Earth stations need to be multiple meters in diameter, making them unwieldy and heavy, Ka-band antennas can be less than a meter across, he notes.

“As you go up through the bands, you can have a smaller dish size because the quality gets higher,” Zarkesh says. “You can have several megabits [of transmission capacity] in a system you can fit into a bag. Everything is smaller, and you can transmit more.”

Antenna suppliers are also leveraging improvements in technology to make satellite communications less complex for users and enable satellite operators to serve a more diverse array of customers than in the past. Some antennas available today can even lock onto a satellite automatically, making it easier for people to learn to set them up with relatively small amounts of training, says Bilal Awada, chief technology officer of C-COM Satellite Systems.

“Everyone wants access wherever they go,” which means the antenna companies are under increasing pressure to deliver easy-to-use systems for use on boats, land-based vehicles and aircraft, Awada says. “We are making sure we offer this kind of connectivity.”

In another example of how the satellite antenna industry strives to makes its products as easy as possible to deploy, ASC Signal announced in October that it would supply seven Ka- and Ku-band antennas as part of a deal to install a teleport in Munich, Germany, operated by HorizonSat Teleports GmbH, a unit of Dubai, United Arab Emirates-based HorizonSat. A key aspect of the contract is that ASC Signal will provide and install the entire facility, as opposed to providing individual components, says Buckley. “One of the challenges we face today when we look to improve antenna technology is you really don’t know how well the installation may go” if it’s not performed by technicians trained by the company.

In addition to permitting satellites to use higher frequencies, technological improvements have enabled satellite operators to place satellites closer together in orbit, which also demands more precise antennas, says Gary Hatch, CEO of Antenna Technology Communications Solutions Inc. (ATCi), makers of Simulsat, an antenna system that can receive satellite signals from more than one orbital slot at once.

 

Transmission Capacity

Despite their hunger for transmission capacity, some satellite operators have been cautious about embracing Ka-band. One example is Intelsat, which traditionally takes a conservative approach to using newly developed systems, Clark says. “We have to strike a balance between pushing manufacturers to change the way they do things [to gain] more optimal performance [and] being cognizant of in-orbit heritage,” he says.

As a result of this mindset, Intelsat has taken a relatively conservative approach to Ka-band even as other satellite operators have closely linked their futures to Ka-band services. Intelsat’s new Epic satellites, due to enter service beginning in 2015, will carry C-, Ku- and Ka-band payloads, but Clark emphasizes that Intelsat is being careful not too rely too heavily on any one frequency range.

“We have a long history of using C- and Ku-band frequencies, but we are gradually moving [toward] Ka-band,” he said. “We have great resources in space, and we are continuing to try to build on them.”

Other operators, by contrast, have embraced Ka-band at the core of their businesses. These companies include Yahsat, based in Abu Dhabi, United Arab Emirates, provider of the YahClick satellite broadband service, and 03b Networks of Jersey in the United Kingdom, which is building a global broadband system using a fleet of middle-Earth-orbit satellites.

When Iridium Communications deployed its global fleet of mobile-communications spacecraft in the late 1990s, the firm was among the first companies to deploy Ka-band services commercially. The company’s fleet of low-Earth-orbit satellites, launched in 1997, uses Ka-band to connect its gateways around the world with its satellites. The Iridium spacecraft also communicate with each other in space using Ka-band transmissions.

Relatively little will change in terms of the way the new Iridium system handles Ka-band transmissions, says S. Scott Smith, executive vice president of Iridium. The antennas will be physically similar, and Iridium has sufficient Ka-band spectrum to handle faster data rates, he says. “We solved those problems 15 years ago,” says Smith. “We were very cutting edge in the 90s.”

A bigger issue for engineers working on the new satellite system has been the fact that Iridium’s L-band allocation has not changed, even though its future handsets will be capable of handling faster data transmissions, according to Smith, who is overseeing the development of the Iridium NEXT system. “The challenge is [fitting] more users and higher data rates into the same 5.5 megahertz of spectrum. It’s all about building electronics so they are more spectrally efficient,” he comments.

Smith says Iridium had to build time into its development schedule to allow engineers to devise new phased array antennas to enable its satellites to deliver better bit rates with a fixed amount of L-band spectrum. The company also wanted to ensure that existing handsets would be able to function with the new satellites, he says, making it necessary to develop equipment that could deliver higher speeds while remaining compatible with handsets based on technology developed more than a decade ago.

Major declines in the size of circuitry, accompanied by jumps in computer speeds, improvements in the algorithms used to process data and the advent of better modems, have made it possible for Iridium to achieve these goals, Smith says. “The size of the antennas and the optics [needed] to transmit or receive energy haven’t changed,” he says.

Aside from the technical challenges that define satellite communications, antenna companies also have to manage the logistical and administrative aspects of supporting space-based communications. This involves working with satellite operators to ensure that antennas will operate properly with particular spacecraft, industry officials say.

”Without a ground station you don’t have a satellite network. We work very closely with operators to make sure we’re meeting every specification out there with our antennas,” says Buckley. “We need to know what their plans are to know how they want their signals radiated to their satellites.”

 

Optimal Service

In addition to meeting requirements laid out by satellite operators to prevent interference and ensure optimal service, antenna companies also must stay abreast of and comply with a broad array of complex international, regional and country-specific regulatory requirements, says Sharon Goldenberg, vice president and general manager of satellite communications at Orbit Communication Systems Based in Netanya, Israel. Orbit specializes in satellite antennas for use on moving vehicles on land and at sea.

Keeping up with these requirements has become more of a priority in recent years, Goldenberg says. “Strict regulatory compliance was not so much of a requirement in terms of system design [10 or 15 years ago]… you could find lots of systems that did not meet the regulations perfectly.”

The regulatory and technical requirements are balanced by the business opportunities created by the satellite industry’s growing need for lighter and less-expensive antennas, Goldenberg says. Orbit has responded to this demand with products such as its OrBand antenna system, which combines a highly compact design with the ability to meet the latest industry standards, Goldenberg adds.

“Smaller systems that are more cost-effective and comply with the regulations are contradictory requirements,” but that’s the challenge the antennas industry must constantly meet Goldenberg says. “The way to do it is by constant innovation…customers expect us to be able to support the progress of technology.”