Accession Number : AD0487494

Title :   FULL-SCALE PATTERN MEASUREMENTS OF SIMPLE HF FIELD ANTENNAS.

Descriptive Note : Special technical rept.,

Corporate Author : STANFORD RESEARCH INST MENLO PARK CA

Personal Author(s) : Ray, Willaim A.

Report Date : MAY 1966

Pagination or Media Count : 78

Abstract : This report is concerned with pattern and impedance measurements on typical HF field-expedient antennas--slant wires, inverted L's and unbalanced dipoles--installed over open farmland in California. Measurements of a balanced dipole and a short monopole over metal ground screens are included for comparison. Contour maps of the radiation patterns were measured with an aircraft-towed transmitter at elevation angles between 3 and 60 degrees in two polarizations, and the response ratios between the two polarizations were tabulated. Several frequencies between 2 and 15 Mc/s were measured on each antenna. Input impedances are given for each antenna over this frequency range. The results clearly demonstrate that physically simple antennas are not necessarily electrically simple. Pattern distortions due to imperfect ground, as well as considerable radiation from counterpoise wires and the outside of coaxial feedlines, were observed. The unbalanced dipole feedlines, in particular, radiated below the dipole's half-wave resonance, although no feedline radiation was evident at resonance. (Author)

Descriptors :   (*ANTENNA RADIATION PATTERNS, MEASUREMENT), (*DIPOLE ANTENNAS, ANTENNA RADIATION PATTERNS), (*ANTENNAS, ANTENNA RADIATION PATTERNS), ELECTRICAL IMPEDANCE, HIGH FREQUENCY, POLARIZATION, ANTENNA FEEDS, ELECTROMAGNETIC RADIATION, RESONANT FREQUENCY.

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE