Lockheed Martin and Penn State University have developed an innovative antenna technology that is now under consideration for use in next-gen GPS satellite payloads. They worked together to dramatically improve the design of the conventional short backfire antenna by significantly increasing its aperture efficiency (gain), without affecting its rugged and compact design, nor increasing its weight.
This type of antenna was originally developed in the 1960s at the Air Force Research Lab. Since then, it has been used in many ground, sea and space applications, perhaps most notably in the communication between NASA and the Apollo spacecraft, and it is still in use on terrestrial communication antenna towers today. However, few significant advances have been made to this decades-old design.
To use this type of antenna in space, it is important that the antenna be high performing and reliable, as it gets only once chance. The newly developed antenna is smaller, lighter, has higher efficiency and is more mechanically robust than the heritage designs used on GPS satellites. It can also withstand the tough environment in space. According to Penn State's Douglas Werner, the research team was able to engineer the electromagnetic properties to meet the stringent radio-frequency (RF) requirements without sacrificing other operational requirements that are unique to the space environment.
These properties are made possible through the use of metamaterials. Compared to conventional short backfire antennas, the new antenna offers a one decibel increase in gain (25 percent increase); a hexagonal shape instead of the circular shape, which results in an additional gain increase when used in an array antenna application; and dual band capability that allows the antenna to operate with high efficiency at the two frequencies required for GPS applications.
The ongoing collaboration works exceptionally well. Penn State is a world leader in metamaterial-enabled RF systems and the associated electromagnetic simulation and optimization tools required to realize the design and implementation of the proposed concept. Lockheed brings Penn State’s team, the vision, and they do the heavy computational lifting with their cutting edge capability. Because Lockheed Martin won the contract for the next generation of GPS satellites, the research team's design may be a perfect fit for future GPS satellite payloads, a fact that Werner and his graduate students find particularly exciting.
The paper with the research results, "A Metamaterial-Enabled Design Enhancing Decades-Old Short Backfire Antenna Technology for Space Applications," was published in Nature Communications.
