ETS-Lindgren 5411 GTEM! Test Cell - Manual (Page 35)

GTEM! Use
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6.0 GTEM! Use
The intended use of the Gigahertz Transverse Electromagnetic (GTEM!™) Cell is
for radiated immunity testing and radiated emissions testing. The following
sections on GTEM! usage provide a general overview of these uses. Note that
the test operator, as with any test facility, must plan and implement the testing of
all devices thoroughly to ensure repeatable results.
Radiated Immunity Testing
Radiated immunity testing is conducted to ascertain if the Equipment Under
Test (EUT) will respond to radiated energy in the electromagnetic ambient in a
deleterious manner. The GTEM! provides an ideal facility for the accomplishment
of such tests in a laboratory environment. Immunity testing is typically performed
using either of the following techniques.
S
UBSTITUTION
M
ETHOD
This method uses the principle of calibrating the test volume. An E-field probe is
positioned in the center of the test plane and the input power is increased until
the required test field is measured. The input power is then recorded as a
function of frequency to create an empty volume calibration file.
For the test, the field probe is replaced by the EUT and the forward power values
of the calibration file are replayed while the device is monitored.
D
IRECT
M
ETHOD
In this method the field probe and EUT are both placed in the GTEM! and the
forward power increased until the required field is measured. This is repeated for
each frequency as the EUT is monitored.
The test setup usually consists of the components shown in Typical Automated
Radiated Immunity Test Setup on page 37.