18
July 6, 2010
AN1559.0
WLAN aggressor cancellation. Once the “WLAN
Optimization Setup (Static Coupling Channel)” is ready,
use the software provided to configure the device as
previously described:
1. Select the WLAN frequency band of operation.
2. Start with the lowest gain setting.
3. Then adjust the I and Q (or gain and phase) until the
maximum attenuation is achieved at the desired
frequency.
Figure 18 is an example of the type of cancellation that
should be achieved when the I and Q values have been
optimized.
ATTENUATOR PAD
TO SET COUPLING LOSS
WLAN AGGRESSOR
NETWORK
ANALYZER
QHX220
CANCELLATION
NODE
POWER
SPLITTER
PORT 1
PORT 2
POWER
SPLITTER
50
Ω
TERMINATION
PATH
FIGURE 17. WLAN OPTIMIZATION SETUP DIAGRAM
-90
-40
-30
-20
-10
0
-50
-60
-70
-80
AFTER CANCELLATION
BEFORE CANCELLATION
FIGURE 18. EXAMPLE OF OPTIMUM CANCELLATION (WLAN)
Application Note 1559