German firm QEST (Booth No. 4672) is here at NBAA presenting its line of compact satellite communications antennas with new superconducting sensor and micro-cooling technology. The company said the antennas offer about twice the performance of existing models at half the size.
According to QEST’s chief technology officer, Dr. Joerg Oppenlaender, the new dual-band (Ku- and L-bands) fuselage-mount antenna measures less than 17 inches in diameter and six inches in height and weighs 33 pounds (including the antenna’s tracking platform). It is capable of transmitting voice and high-speed data and receiving satellite TV signals.
One claimed advantage is that the antenna requires less signal strength and so will maintain performance in regions of the world where satellite coverage is not complete, such as over the Atlantic and Pacific oceans. Compared with a typical satcom antenna which generally requires around 50- to 52-EIRP (equivalent isotropic radiated power) signal strength from a satellite, the QEST unit can operate with a signal as low as 46 dBW EIRP for standard digital video broadcast satellite (DVB-S) or direct satellite service (DSS) modes.
The QEST antenna also boasts an extended bandwidth that allows it to operate in both Ku- and L-bands simultaneously. Other satcom systems would have to have two separate antennas positioned on different parts of the airframe and need larger antennas to operate at comparable EIRP levels.
The QEST equipment’s bandwidth capacity allows it to multi-task a variety of communications requirements simultaneously so that, for example, high-definition live TV can be viewed in the cabin at the same time that passengers are accessing the Internet or making phone calls. The L-band connection can operate at datalink speeds of up to 432 kilobytes per second in receive and transmit mode, allowing for permanent, global connection to Inmarsat’s Swift64 and SwiftBroadband services. Simultaneously, the Ku-band link can receive at speeds of up to 40 megabytes per second per transponder.
The combination of the two bands creates a hybrid, asymmetric Internet connection that operates similarly to a ground- based network but with higher data rates. QEST also believes that the antenna’sperformance can help satcom service providers to overcome congestion issues that can compromise connection rates.
Working with a large industrial partner in a research and development project that was concluded in June, QEST has successfully implemented several proofs-of-concept and prototype applications of its antenna. The unit’s performance parameters have been confirmed by an independent test laboratory, and it has also passed all relevant environmental tests (for example, temperature and vibration).
Oppenlaender told NBAA Convention News that the foundation for the patented antenna’s superior performance is the application of an advanced cryo-electronic, low-noise amplifier that operates at very low temperatures and doesn’t reduce the signal-to-noise ratio of the receiving antenna. The micro-coolers used for the antenna have already been proved in demanding real-world applications, including use in the forward-looking infrared systems for Eurocopter’s Tiger attack helicopter.
The other key factor for the new antenna is the use of super-conducting elements made from special ceramic materials that further reduce the noise output of the receiving system. QEST believes it is significantly ahead of leading avionics houses in having advanced these aspects of antenna technology.
According to marketing director Michael Stobinski, the company is now looking to engage with hardware partners and satcom service providers to put the antenna into service on an aircraft. Here in Atlanta this week, company sales executives are also eager to talk with business jet operators who would be interested in buying the system.
Stobinski indicated that the initial purchase price of the QEST system will likely be slightly more expensive than existing antennas. However, he said he fully expects operators to benefit from lower cost of ownership due to the reduced structural reinforcement required as well as lower fuel burn and maintenance costs. The company is targeting a mean time between failure rate of between 15,000 hours for business jet applications and 40,000 hours for commercial airliners.
QEST is part of the Draexlmaier group and is based at Holzgerlingennear near Stuttgart. The superconductor research work has been done in association with Germany’s University of Tubingen.
