ETS-Lindgren 3144 Log Periodic Dipole Array - Manual (Page 7)

1.0 Introduction
The ETS-Lindgren Model 3144
Log Periodic Dipole Array is a
linearly polarized, broadband
antenna designed to operate over the
frequency range of 80 MHz to 2 GHz.
The choice of scaling factors, the various diameters of each element, and the
center-to-center spacing of the booms are such that excellent VSWR
characteristics are obtained throughout the operating frequency range.
The precise design of the feed and the positioning of the elements on the boom
yield optimum phase relationship. This causes the active region, at any given
frequency, to propagate RF energy towards the smaller elements leaving the
elements behind it electrically dead.
The constant gain of the antenna yields an antenna factor which varies linearly
with frequency. The variation is smooth; therefore, accurate interpolation of
performance between specified frequency points is simple.
The Model 3144 is provided with an integral mount and the necessary
attachments to mount the antenna to either a tripod (with a 1/4–20 threaded
mount) or an ETS-Lindgren antenna mast. For the variety of mounting options
available for the Model 3144, see Mounting & Assembly on page 15.
Each Model 3144 is individually calibrated at one meter per SAE ARP 958 and at
three and 10 meters per ANSI C63.5. Actual antenna factors and a signed
Certificate of Calibration Conformance are included.
Introduction | 7