Development of a Beacon Antenna System with Automatically Controlled Directivity

Item

Title
Development of a Beacon Antenna System with Automatically Controlled Directivity
Creator
Kazel, S.
Rodriguez, G.
Date
1962
Abstract
The surface of interference nulls in the combined pattern of two or more radiating elements is described. It is shown that phase-modulation of the individual radiators can reduce the severity of the nulls. If suitable phase modulation waveforms are used, the nulls are completely eliminated. Sine-wave linear, and square-wave phase modulation are compared. It is shown that sine-wave modulation creates fewer interfering sidebands than square-wave modulation. On the other hand, square-wave modulation appears useful for any number of interfering radiators, while sine-wave modulation is limited to three radiators. Switching between individual radiators is shown to give identical results as square-wave phase modulation. Experimental measurements of the radiation pattern of a 3-slot antenna on a 15 inch diameter cylinder and the effects of 180 degree phase shifts are presented. It is verified that the phase reversal interchanges maxima and minima for both linear and circularly polarized receiving antennas.
Date Issued
1962-12-07
Extent
45
Corporate Author
Armour Research Foundation
AD Number
AD-292 641
Contract
DA 11-022-ORD-4222
Distribution Conflict
Yes
Index In
U.S. Government Research Reports, Vol. 38, No. 7, p. 31
Index Price
$4.60
Distribution Classification
2
DTIC Record Exists
No
Report Availability
Not available via Contrails
Type
report
Item sets
Illinois Tech Related
Public Access Conflicts

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