WLAN TX Measurements (Option K91) R&S FSL
1300.2519.12 2.138 E-11
Literature
[
1]
Institute of Electrical and Electronic Engineers, Part 11: Wireless LAN Medium Access
Control (MAC) and Physical Layer (PHY) specifications, IEEE Std 802.11–1999, Institute of
Electrical and Electronic Engineers, Inc., 1999.
[2]
Institute of Electrical and Electronic Engineers, Part 11: Wireless LAN Medium Access
Control (MAC) and Physical Layer (PHY) specifications: Higher–Speed Physical Layer
Extensions in the 2.4 GHz Band, IEEE Std 802.11b–1999, Institute of Electrical and
Electronic Engineers, Inc., 1999.
802.11b RF carrier suppression
Definition
The RF carrier suppression, measured at the channel center frequency, shall be at least 15 dB below
the peak SIN(x)/x power spectrum. The RF carrier suppression shall be measured while transmitting a
repetitive 01 data sequence with the scrambler disabled using DQPSK modulation. A 100 kHz
resolution bandwidth shall be used to perform this measurement.
Measurement with the R&S FSL
The RF carrier suppression as defined in the standard is a determination of peak ratios. The
unscrambled 01 data sequence provides a spectrum with distinct peaks enveloped by the transmit filter
spectrum. An IQ offset leads to an additional peak at the center frequency.
The following measurement sequence can be used in normal spectrum mode:
1. Use power trigger or external trigger
1. Use gated sweep with gate delay at payload start and gate length = payload length
(Delay–Comp ON and RBW = 50 MHz for gate settings)
2. Set RBW = 100 kHz
3. Set Sweep Time = 100 ms
4. Set Span = 20 MHz
5. Set Detector = RMS
6. Set Marker 1 to center frequency
7. Use Marker 2 as Delta Marker and set it to max. peak
Fig. 2-89 is a screenshot of this measurement. The delta marker shows directly the RF carrier
suppression in dB (white circled value).
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