Broadband Beat: Dishing It Out
By Theresa Foley
The coming wave of new broadband satellites would be useless without comparable advances in user terminals, and earth station developers have a number of impressive advanced antenna designs in the works that will be introduced in the near future. They range from flat antennas to deliver multimedia services to moving platforms to smaller and more efficient stationary antennas that will help satellite systems compete with terrestrial broadband access methods.
Skygate BV, headquartered in Amsterdam with an R&D center in Sofia, Bulgaria, is designing flat antennas with electronically-configurable components for use with DBS and multimedia systems. “We are solving a 30 year puzzle of the affordable flat, electronically steerable antenna,” says Buzz Beitchman, Skygate’s CEO. Skygate will license its technology to others, rather than building the antennas directly.
Skygate’s antennas will be easier to install and use than regular parabolic antennas, and more functional than existing flat satellite antennas because of the advanced electronics in the chips, according to Beitchman. The DBS version of the antennas, which will be in production by late next year for Ku-band satellite users in the United States, will be able to electronically re-point itself at one of three orbital locations, allowing it to capture signals from three satellite locations. He expects that antenna to cost less than $300. By 2002, another small, flat antenna for mobile multimedia uses would become available. The flat antennas are mountable on cars, trucks and boats for users who want to access the Internet or watch TV while moving. The cost should be less than $1,000 at the outset.
Boeing is also developing flat, electronic phased array antennas for its multimedia commercial service for aircraft, Connexion, which will use satellites to provide high-speed data communications at a price comparable to cellular phone service, according to the company. Aircraft equipped for the service will have two antennas, one for transmitting and one for receiving. Ed Laase, Boeing Connexion director of network and operations, says the technical advances include the thinness of the antennas (2 inches), the ability to get guidance information from the aircraft’s systems, and the high number of elements in the antenna arrays (1,552 for receive and 872 for transmit), which will translate into more gain and higher data rates.
The receive antennas are flying now on business jets, while the transmit antennas will begin flight tests in October, Laase says. Installation of the systems will begin in late 2001, with service to start shortly after in North America. Boeing plans to put the system into 400 aircraft the first year, with the production rate of the antennas going to 1,000 systems a year by 2003 as the service is introduced in Europe and then globally.
For fixed broadband multimedia services, several new technological designs are getting ready to be deployed. Norsat International Inc. in Burnaby, British Columbia, has developed complete two-way Ka-band outdoor units for use with SES Astra’s Broadband Interactive multimedia satellite service. The dishes will be delivered starting in November, according to Don Filmer, Norsat’s vice president for strategic development. Initially, 10,000 will be built, but Norsat hopes to deliver much higher quantities in the coming years to SES and other Ka-band operators such as Korea Telecom. Norsat builds the outdoor units, while EMS of Norcross, GA, supplies the indoor electronic components for the system.
Designing the outdoor units for high manufacturing volumes, in the hundreds of thousands or millions, has taken longer than originally anticipated, Filmer says. “The current VSAT assembly process is labor intensive and a small volume activity. To satisfy the need to mass produce, we had to concentrate on the packaging of high frequency devices to be handled by automated assembly,” he says.
Filmer reports that the prototype earth stations function well in rain conditions, but he would not divulge the parameters or limits of performance in rain. “Rain fade does not seem to be an issue,” he concludes.
Skybridge, the Alcatel-led low earth orbit constellation for last mile broadband access, also has a novel earth station in development, which it has displayed at industry shows for nearly a year. The Skybridge antenna has a spherical case that encloses several moving parts that are able to mechanically track multiple satellites as the spacecraft cross the sky, allowing the Skybridge handover of a customer’s connection to occur.
Another program that is related to satellites comes from Satellite Export and Engineering Inc. (SEE), which is supplying 8,000 systems of low noise block downconverters and feedhorns for a Ka-band satellite-based MMDS project. Acording to SEE, this is a first-time application for using Ka-band on a terrestrial wireless transmission system.
Dennis Urquhart, SEE vice president, says the components are a special application of technology because the LNBs that are being used are in three different gain applications and are still obtaining a tight L.O. stability. This allows the transmission to be sent at various distances of one mile up to 50 miles without overpowering the LNB. SEE manufactures the line of Patriot antennas and subcomponents for many of the large satellite operators.
All of the antenna makers are striving to bring costs down while they improve the technology, which means that more consumers are likely to adopt satellite solutions if they are price competitive. “The world wants two things, first to stay connected, and second to be mobile,” says Laase. “The antenna technologies are helping us do that.” v
Theresa Foley is Via Satellite’s Senior Contributing Editor.