ETC Report No. : 16-09-RBF-027
Sheet 8
of 36 Sheets
FCC ID:
2AC96WDP
8
4 RADIATED EMISSION MEASUREMENT
4.1 Applicable Standard
For intentional radiators, according to §15.249 (a), the fundamental field strength shall not
exceed 94 dBµV/m and the harmonics shall not exceed 54 dBµV/m. For out band emission
except for harmonics shall be comply with §15.209 or at least attenuated by 50 dB below
the level of the fundamental.
4.2 Measurement Procedure
A. Preliminary Measurement For Portable Devices
For portable devices, the following procedure was performed to determine the maximum
emission axis of EUT:
1. With the receiving antenna is H polarization, rotate the EUT in turns with three
orthogonal axes to determine the axis of maximum emission.
2. With the receiving antenna is V polarization, rotate the EUT in turns with three
orthogonal axes to determine the axis of maximum emission.
3. Compare the results derived from above two steps. So, the axis of maximum emission
from EUT was determined and the configuration was used to perform the final
measurement.
B. Final Measurement
1. Setup the configuration per figure 1 and 2 for frequencies measured below and above 1
GHz respectively. Turn on EUT and make sure that it is in normal function.
2. For emission frequencies measured below 1 GHz, a pre-scan is performed in a shielded
chamber to determine the accurate frequencies of higher emissions will be checked on a
open test site. As the same purpose, for emission frequencies measured above 1 GHz, a
pre-scan also be performed with a 1 meter measuring distance before final test.
3. For emission frequencies measured below and above 1 GHz, set the spectrum analyzer
on a 100 kHz and 1 MHz resolution bandwidth respectively for each frequency measured
in step 2.
4. The search antenna is to be raised and lowered over a range from 1 to 4 meters in
horizontally polarized orientation. Position the highness when the highest value is
indicated on spectrum analyzer, then change the orientation of EUT on test table over a
range from 0
。
to 360
。
with a speed as slow as possible, and keep the azimuth that
highest emission is indicated on the spectrum analyzer. Vary the antenna position again
and record the highest value as a final reading. A RF test receiver is also used to confirm
emissions measured.
