The antennas have been developed for use in Leo One's non-voice, non-geostationary mobile satellite service (NVNG MSS) system, commonly known as a Little LEO system.

The Leo One system will consist of 48 low-Earth orbiting satellites capable of providing near real-time store-and-forward messaging services to users around the world.

The Leo One satellite antennas were designed to optimize communications with receivers on the Earth within the satellite footprint.

The proprietary satellite antenna design is expected to provide significant benefits in the quality and reliability of service to be provided to subscribers.

Radiation patterns of the prototype satellite antennas based on the Leo One system design are successful.

Satellites of the Leo One constellation need to be able to communicate with receivers at any point on Earth visible to the satellite. In order to transmit the same power density to any point on Earth under the satellite, the antennas on the Leo One satellite must radiate in an "isoflux" pattern.

Quadrifilar helical antennas were chosen because they are particularly suited to produce "isoflux" coverage as well as satisfy other system requirements.

Each satellite will have two (2) UHF and one (1) VHF quadrifilar helical antennas as shown in the artist's conception right. The three antennas were initially designed on a computer using specialized antenna analysis software.

A baseline design for the satellite antennas that satisfies Leo One's system requirements was produced, and prototype antennas were fabricated (photo right) and tested on the deployment mechanism.

Measurements of the antenna radiation patterns were taken and compared against the theoretical predictions. The patterns were in excellent agreement, experimentally verifying the design of the Leo One satellite antennas. The antennas are now in the engineering development phase.

Leo One received its FCC license to construct, launch and operate its non-voice, non-geostationary mobile satellite service (NVNG MSS), commonly known as Little LEO mobile satellite service, on February 13, 1998. Its 48-satellite constellation is slated to be operational in 2002. Leo One will offer a wide range of near real-time messaging services including tracking and fleet management, monitoring and remote control, two-way messaging, emergency services and transaction processing.