Introduction - ETS-Lindgren BiConiLog 3140 Manual

MODEL 3140 BICONILOG™ ANTENNA

INTRODUCTION

© EMC TEST SYSTEMS, L.P. – MARCH 2002
REV C – PN 399258
The ETS-Lindgren EMCO brand Model 3140 is a high-
field addition to the popular bow-tie/log periodic
combination BiConiLog
field-to-power ratio at low frequencies of any of the
BiConiLog™ antennas.
specifically to generate the field levels required for
immunity/susceptibility tests required by standards such as
IEC/EN 61000-4-3 using the lowest amount of input power
possible.
A BiConiLog™ antenna combines a broadband biconical-
like bow-tie antenna with a standard LPDA (log periodic
dipole array) to replace the traditional use of two antennas
in the 26-1000 MHz EMC test frequency range. Many
EMC antennas are variations of a standard tuned dipole,
which must be nearly half a wavelength long to transmit or
receive energy most efficiently. Thus, at 26 MHz, a tuned
dipole would have to be approximately 5.3 meters long,
about 4.6 meters long at 30 MHz, and 2.8 meters long at 50
MHz. Unfortunately, this is too unwieldy for many
anechoic chambers and test sites. The end plates of the
Model 3140 T bow-ties make the bow-tie antenna segment
look like an antenna twice as long as its 1.6 meter length.
The result is about a 10-dB improvement in low frequency
transmit gain compared to a same-length regular bow-tie.
Although bow-ties have been used for all of the elements
on some log-periodic antenna designs in the past, in EMC
applications the advantage gained is an extension of the
TM
family, providing the highest
The Model 3140 is designed
Introduction
1