Manual

ANSI C63.17-2006
Methods of Measurement of the Electromagnetic and Operational Compatibility of UPCS Devices
4.4 Limits for radiated and conducted tests
When conducted tests are performed, the limits from Equation (1), Equation (2), and Equation (3) or
Equation (4) in 4.3.1 through 4.3.4 apply directly. For radiated tests, those limits must be translated to the
equivalent limits on EIRP and monitoring threshold field strength, respectively. EIRP limits corresponding
to Equation (1) are given in the following equation:
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gGGP
gGgP
AA
A
≤+
>+
≤
,
,
EIRP
max
max
EUT
(5)
To test for monitoring threshold compliance using radiated techniques, a reference antenna is used to
generate the required field strength at the monitoring antenna. The EUT’s antenna gain affects the EUT’s
radiated interference level into other users intended to be protected by the LBT and LIC provisions, and the
test for monitoring compliance needs to account for this. Accordingly, the transmit power P
Tref
that must be
applied to the reference antenna terminals to induce the effective signal detectable by the EUT’s monitoring
elements can be expressed in terms of the EUT’s antenna gain as follows:
()
REFTref
4log20 GrGTP
AM
−
−
−
=
π
λ
(6)
where
T
M
is the desired signal level received by the EUT
G
A
(dBi) is the EUT’s antenna gain in the direction and polarization of maximum
G
REF
(dBi) is the gain of the reference antenna in the direction of the EUT and copolarized
λ is the signal wavelength in meters
r is the distance from the reference antenna to the EUT monitoring antenna in meters
4.5
4.6
Conducted measurements of products with identical collocated transmitting
and monitoring antennas
Disconnect the EUT antenna and measure power P
EUT
at its terminals during EUT transmission, as
specified in Clause 6 of this standard. Measure the monitoring threshold(s) using the procedures in Clause 7
of this standard.
Conducted measurements of products with collocated transmitting and
monitoring antennas of different types
When the monitoring antenna is different from the transmitting antenna, it must be verified that the
monitoring antenna provides coverage equivalent to or better than that of the transmitting antenna. This
means that the monitoring system shall cause deference to any transmission of sufficient strength to induce
a power level in the EUT transmit antenna that exceeds the threshold for the EUT, measured at the
transmitting antenna input.
The transmit power compliance test of Clause 6 shall be performed as stated in 4.5. Calculate the maximum
appropriate threshold T
L
or T
U
using Equation (2) or Equation (3), and verify that the EUT transmits when
interference power sufficiently less than T
L
or T
U
is applied to the monitoring antenna terminals and defers
when interference power equal to or greater than T
L
or T
U
is applied to the terminals.
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Because the EIRP limit is independent of G
A
for G
A
> 3 dBi, and most practical radiating devices will not have a gain sufficiently
below 3 dBi for the difference 3 dBi − G
A
to be accurately measurable, there may be a gain-independent EIRP limit in the future.
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