Accession Number:

AD0653165

Title:

FULL-SCALE PATTERN MEASUREMENTS OF SIMPLE HF FIELD ANTENNAS IN A US CONIFER FOREST

Descriptive Note:

Special technical rept.

Corporate Author:

STANFORD RESEARCH INST MENLO PARK CA

Personal Author(s):

• Ray, William A.
• Barker, Gary E.
• Martensen, Sandra S.

Report Date:

1967-02-01

Pagination or Media Count:

136.0

Abstract:

During May and June of 1965, measurements of field-expedient antenna impedance and radiation patterns were conducted in a conifer forest. The antennas measured included dipoles, slant wires, and inverted Ls. The pattern measurements were conducted with an aircraft-towed transmitter. The results are presented on contour maps showing individual polarization response for elevation angles from 5 to 60 from the horizon and power response from 5 above the horizon to the zenith for several frequencies between 2 and 15 Mcs. Input impedances are presented on Smith charts for each antenna over the frequency range that the above pattern data are presented. In addition, curves of resonant frequency and input impedance as a function of antenna height are presented for selected dipoles. The results demonstrate that the trees surrounding the antennas begin to cause perturbations to the vertical polarization response of antennas at approximately 8 Mcs.

Descriptors:

• *MEASUREMENT
• *HIGH FREQUENCY
• *ANTENNAS
• DATA PROCESSING
• WIRE
• MAPS
• POWER
• ANTENNA RADIATION PATTERNS
• RADIO TRANSMITTERS
• INVERTER CIRCUITS
• DIPOLE ANTENNAS
• FORESTRY
• ANTENNA ARRAYS
• ELECTRICAL IMPEDANCE
• SITE SELECTION
• TABLES(DATA)
• TREES
• AIRCRAFT
• POLARIZATION

Subject Categories:

• Electrical and Electronic Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE