ETS-Lindgren BiConiLog 3140 Manual page 7

MODEL 3140 BICONILOG™ ANTENNA
© EMC TEST SYSTEMS, L.P. – MARCH 2002
REV C – PN 399258
improve impedance matching to the bow-ties. Even though
the Model 3140 is highly balanced (symmetry +/- 0.5 dB),
in vertically polarized measurements cable position can
effect results, so it is recommended that the cable be
suspended horizontally back from the antenna at least 1
meter before any vertical drop. Below 150 MHz, bow-tie
radiation dominates with a dipole-like pattern, while above
150 MHz the radiation in the plane of the elements is
directional.
The antenna has dual mounting bracket and 1/4x20 UNC
knob for attaching to ETS-Lindgren tripod and tower
adapters. The brackets are spaced to align with the
mounting holes on the Model 7-TR tripod and the ETS-
Lindgren towers. Typical antenna factor data is included in
Figure 11.
Note: The Model 3140 is designed only for immunity
testing. The large size of the antenna makes it impractical
for emissions testing where height scanning is required,
and the bow-tie end plates increase the measurement
uncertainty when the antenna is polarized vertically. Thus,
individual calibrations are not provided for the Model
3140.
Introduction
3