AH-118 Horn Antenna
Theory of Operation
3
This chapter explains the following:
a)
Overview
b)
Theory of Operation
3-1
3.0 Overview
This section describes the theory of operation of the Horn Antenna.
3.1 Theory of Operation
Broadband antennas allow measurement of signals over a wide frequency
range. These antennas do not require any tuning or balun switching during
measurement. It is very useful for sweep measurement over the frequency
range of operation. Models AH-118 Horn Antennas are broadband
antennas that operate in the frequency range of 1 GHz to 18 GHz.
Model AH-118 can both receive and Transmit over the frequency range of
operation and ise used for susceptibility and emissions testing in EMC
Laboratories.
Before the Horn antennas are used for measurement they have to be
calibrated. Typically antenna calibration is performed in an open field test
site( OATS). During calibration a known field strength (dBuV/m) is
generated around the antenna at each frequency (1 GHz - 18 GHz). The
difference between field strength (dBuV) received by the antenna and
known field strength generated ( dBuV) is the antenna factor (dB) for that
frequency. During EMC testing the antenna factor for the frequency of
interest is added back to reading on the EMI meter or spectrum analyzer
to measure field strength.
dBuV/m (field strength) = dBuV (output measured) + Antenna Factor
Distributed by: Reliant EMC LLC, +1 408 916
‐
5750, [email protected], www.reliantemc.com
