Abstract: A waveguide has distal, medial and proximal sections. The distal and medial sections rotate relative to each other and to the proximal section. In a first configuration, the waveguide transforms linearly polarized electromagnetic radiation at the proximal end of the proximal section to linearly polarized electromagnetic radiation at the distal end of the distal section and vice versa. In a second configuration, the waveguide transforms linearly polarized radiation at the proximal end of the proximal section into circularly polarized electromagnetic radiation at the distal end of the distal section and vice versa. Preferably, the distal and medial sections include respective eight-wavelength polarizers and the proximal section includes a quarter-wavelength polarizer. A multi-band antenna feed includes two such waveguides, one nested inside the other, for transforming electromagnetic radiation of respective frequency bands.

Abstract: An effective marine stabilized antenna system, in terms of antenna to radome size and antenna/RF performance complies with all relevant worldwide SatCom regulations. The combination of a dual offset Gregorian antenna (DOGA) with a stabilized polarization over elevation over tilt over azimuth pedestal, and a control/stabilization algorithm, ensures antenna orientation restrictions guarantee compliance with side-lobe intensity regulations. Operating a dual offset Gregorian antenna substantially within a pre-determined antenna cut range of a 45 degree angle relative to a configuration of the antenna and a relative position of a target provides antenna performance that complies with applicable SatCom regulations, despite having to flip the antenna 90 degrees to continue tracking the satellite.

Abstract: A method for operating a ring network includes the steps of configuring the ring network with static configuration information and then deterministically exchanging operational data between a plurality of nodes on the ring network, while operating the ring network in accordance with the static configuration information. This system facilitates communications that meet the high reliability and performance requirements of vehicle communications, in particular in aircraft data networks (ADNs), while reducing the cost, weight, and complexity of conventional implementations.

Abstract: A waveguide has distal, medial and proximal sections. The distal and medial sections rotate relative to each other and to the proximal section. In a first configuration, the waveguide transforms linearly polarized electromagnetic radiation at the proximal end of the proximal section to linearly polarized electromagnetic radiation at the distal end of the distal section and vice versa. In a second configuration, the waveguide transforms linearly polarized radiation at the proximal end of the proximal section into circularly polarized electromagnetic radiation at the distal end of the distal section and vice versa. Preferably, the distal and medial sections include respective eight-wavelength polarizers and the proximal section includes a quarter-wavelength polarizer. A multi-band antenna feed includes two such waveguides, one nested inside the other, for transforming electromagnetic radiation of respective frequency bands.

Abstract: An effective marine stabilized antenna system, in terms of antenna to radome size and antenna/RF performance complies with all relevant worldwide SatCom regulations. The combination of a dual offset Gregorian antenna (DOGA) with a stabilized polarization over elevation over tilt over azimuth pedestal, and a control/stabilization algorithm, ensures antenna orientation restrictions guarantee compliance with side-lobe intensity regulations. Operating a dual offset Gregorian antenna substantially within a pre-determined antenna cut range of a 45 degree angle relative to a configuration of the antenna and a relative position of a target provides antenna performance that complies with applicable SatCom regulations, despite having to flip the antenna 90 degrees to continue tracking the satellite.

Abstract: A ground station antenna includes a LNB with at least one dipole, a feed horn, a waveguide between the LNB and the feed horn, and a rotation mechanism. By rotating a portion of the waveguide, the polarization of an electromagnetic wave propagating between the LNB and a satellite is transformed to match the polarization to (one of) the dipole(s) and to an antenna on the satellite. Another ground station antenna includes a main waveguide, two mutually orthogonal branch waveguides, a coupling mechanism for coupling two orthogonal antenna dipoles to the proximal end of the waveguide, and a transformation mechanism that transforms the polarization of an electromagnetic wave propagating between the branch waveguides and a satellite via the antenna dipoles to match the polarization to one of the branch waveguides and to an antenna on the satellite.

Abstract: A system for stabilizing two antennas on a mobile platform, the antennas including a first antenna associated with a first geo-stationary satellite and a second antenna associated with a second geo-stationary satellite, the system comprising an upper alignment system and a lower alignment system. The upper alignment system is configured for being a common support for the antennas. The upper alignment system has an intermediate element. The upper alignment system is configured for pointing the antennas relative to the intermediate element, such that the angular displacement between the antennas is matched with the angular displacement between the satellites. The lower alignment system is connected to the upper alignment system and the mobile platform. The lower alignment system is configured for maintaining the orientation of the intermediate element in order to compensate for rotation of the mobile platform, such that the antennas are maintained pointing toward their respective satellites.

Abstract: A method for aligning an antenna polarization axes of a dual polarized end-user terminal having an antenna. The antenna is aligned with a satellite in relation to azimuth and elevation. The end-user terminal is configured in an alignment mode to produce a first output corresponding to a first component of a received signal parallel to a first polarization axis of the antenna and a second output corresponding to a second component of the received signal parallel to a second polarization axis of the antenna. The first polarization axis is orthogonal to the second polarization axis. The method includes the steps of: receiving a linearly polarized signal; autocorrelating the first output and the second output to produce a measurement of autocorrelation; and adjusting the antenna polarization axes to minimize the measurement of autocorrelation.