Accession Number : AD0446155

Title :   BEYOND-LINE-OF-SIGHT DATA TRANSMISSION USING ADAPTIVE ARRAY TECHNIQUES,

Corporate Author : MICHIGAN UNIV ANN ARBOR INST OF SCIENCE AND TECHNOLOGY

Personal Author(s) : Wilburn, Frank E.

Report Date : AUG 1964

Pagination or Media Count : 38

Abstract : State-of-the-art developments in adaptive array techniques applied to beyond-line-of-sight data transmission systems are reported. The general theory of beam-steering by means of a directional reference derived from received energy incident on the array elements is reviewed. The Van Atta method of connecting conjugate pairs of array elements and the phase-inversion principle of terminating each receiver element in a phaseinverting device are examined in detail. For each method, array configurations (i.e., planar array, curved array), element spacing, and the effects of polarization are discussed. Consideration is also given to the following areas (with particular emphasis on their applicability to beyond-line-of-sight relays): types of modulation compatible with adaptive arrays, isolation schemes, and frequency offset. The appendixes include the development of general array relationships to determine phase and amplitude characteristics, special circuitry for a receiving array, and the development of a phase-error approximation for a curved Van Atta array. (Author)

Descriptors :   (*DATA TRANSMISSION SYSTEMS, MICROWAVE COMMUNICATIONS), (*MICROWAVE COMMUNICATIONS, DATA TRANSMISSION SYSTEMS), ANTENNAS, DIPOLE ANTENNAS, ANTENNA RADIATION PATTERNS, POLARIZATION, MODULATION, FREQUENCY MODULATION, AMPLITUDE MODULATION.

Distribution Statement : APPROVED FOR PUBLIC RELEASE