User's Manual

Rev 1.34, June 2, 2004
Copyright © 2001-2004 Motorola, Inc. All rights reserved. Page 21 of 44
14. Change the spectrum analyzer settings as follows:
a. Sweep range: 3000 MHz to 11000 MHz
b. Markers: 3100 MHz and 10600 MHz
15. Note the RF power output of the transceiver between the two marked frequencies (3100
MHz and 10600 MHz) and verify that it is below the –41.3 dBm ceiling specified in
paragraph (c) of section 15.517 of the FCC CFR 47, Part 15. The transmit spectrum
should be below -51.3 dBm above 4.9 GHz.
16. Change the spectrum analyzer settings as follows:
a. Sweep range: 10000 MHz to 12000 MHz
b. Markers: 10600 MHz
17. Note the RF power output of the transceiver above the marked frequency (10600 MHz)
and verify that it is below the –51.3 dBm ceiling specified in paragraph (c) of section
15.517 of the FCC CFR 47, Part 15.
18. Change the spectrum analyzer settings as follows:
a. Sweep range: 1164 MHz to 1169.067 MHz
b. Resolution bandwidth setting: 1 kHz
Note 1: A digital spectrum analyzer such as the FSU26 measures RF power contained in
a frequency span specified with the resolution bandwidth value. A digital spectrum
analyzer takes this measurement by determining the power at many discrete points
(called sweep points) between start and stop frequencies (the sweep span). The
instrument divides the sweep span into a number of slices one resolution bandwidth
wide, measures the power in each slice and plots the result. Note that sections of
the sweep span will be missed (i.e. have no data points) if the sweep range divided
by the number of sweep points exceeds the resolution bandwidth. The plot of
resulting measured values would be meaningless. To prevent generation of such
meaningless results, the measurements made in steps 18 through 23 of this
procedure must be broken into sweep points that are about 4/10ths of a resolution
bandwidth. For example, in the GPS band, the 1164 MHz to 1240 MHz span (sweep
span = 76 MHz), 15 separate measurements (5.0667 MHz per measurement with
10001 points means 507 Hz per point) are made to provide approximately two data
points per resolution bandwidth slice. For the 1559 MHz through 1610 MHz span
(sweep span = 51 MHz), 10 separate measurements (5.1 MHz per measurement
with 10001 points means 510 Hz per point) are made to provide approximately two
data points per resolution bandwidth slice.
Note-2: An alternative to the FSU-26 is the ESIB which is designed to automatically
make certified accurate EMI measurements. With general purpose analyzers,
there is no guarantee the results are accurate -- it can be difficult to get known
accurate results due to the flexibility and interaction of the various sweep
parameters that are all under user control. The ESIB forces the steps of
.4*RBW to insure that highly accurate results are obtained and no spectral
peak is lost. It also has the following advantages:
(1) Built in transducer tables as well as a calibrated low-noise (9 dB NF)
preamp, and multiple detectors including an RMS detector. These allow
accurate measurements of the low signal levels in open-air tests because it
allows a real-time display that is calibrated for all antenna and cabling
effects. The real-time display allows frequencies and peak-levels at