7 research outputs found

    Adaptive multibeam antennas for spacelab. Phase A: Feasibility study

    Get PDF
    The feasibility was studied of using adaptive multibeam multi-frequency antennas on the spacelab, and to define the experiment configuration and program plan needed for a demonstration to prove the concept. Three applications missions were selected, and requirements were defined for an L band communications experiment, an L band radiometer experiment, and a Ku band communications experiment. Reflector, passive lens, and phased array antenna systems were considered, and the Adaptive Multibeam Phased Array (AMPA) was chosen. Array configuration and beamforming network tradeoffs resulted in a single 3m x 3m L band array with 576 elements for high radiometer beam efficiency. Separate 0.4m x 0.4 m arrays are used to transmit and receive at Ku band with either 576 elements or thinned apertures. Each array has two independently steerable 5 deg beams, which are adaptively controlled

    Contribution à la morphologie de l'artère saphène chez l'homme

    No full text
    Popowsky J. Contribution à la morphologie de l'artère saphène chez l'homme. In: Bulletins et Mémoires de la Société d'anthropologie de Paris, V° Série. Tome 4, 1903. pp. 596-607

    Zur Entwickelungsgeschichte der Dammuskulatur beim Menschen

    No full text
    corecore