Intersil QHx220 Installation manual

1
Application Note 1559
QHx220 Hardware User Guide
Table of Contents
QHx220 System Overview ................................................................................................................... 2
General Application System Block Diagram for QHx220 .......................................................................... 2
Description of QHx220 System Block Diagram....................................................................................... 2
Essential Factors to Integrating the QHx220 Device into Your System ..................................................... 3
Connecting the QHx220 Evaluation Board to a PC for Manual Control ...................................................... 4
MTV Product Application ..................................................................................................................... 5
QHx220 Board Layout ....................................................................................................................... 5
QHx220 Board Schematics (for MTV) ................................................................................................... 6
QHx220 Board Bill of Materials (for MTV).............................................................................................. 7
MTV Optimization Setup (Static Coupling Channel) ................................................................................ 7
MTV Application Setup ....................................................................................................................... 9
GPS Product Application ................................................................................................................... 10
QHx220 Board Layout...................................................................................................................... 10
QHx220 Board Schematics (for GPS) ................................................................................................. 11
QHx220 Board Bill of Materials (for GPS) ............................................................................................ 12
GPS Optimization Setup (Static Coupling Channel)............................................................................... 12
GPS Application Setup ..................................................................................................................... 14
WLAN Product Application ................................................................................................................. 15
QHx220 Board Layout...................................................................................................................... 15
QHx220 Board Schematics (for WLAN) ............................................................................................... 16
QHx220 Board Bill of Materials (for WLAN) ......................................................................................... 17
WLAN Optimization Setup (Static Coupling Channel) ............................................................................ 17
WLAN Application Setup ................................................................................................................... 19
Q:ACTIVE........................................................................................................................................... 19
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 |Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2010. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
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QHx220 System Overview
General Application System Block Diagram for QHx220
Description of QHx220 System Block
Diagram
The block diagram shown in Figure 1 illustrates the
typical system architecture for the implementation of the
QHx220 noise canceller. The QHx220 integrates the LNA
gain stages in the sampler path as well as the DACs
which control the I and Q (or ultimately the gain and
phase) of the device. The LNA gain stages and the I and
Q are controlled via the SPI bus interface. The GUI
software supplied with the evaluation board provides a
means to manually tune all of these parameters.
A known noise source is sampled by a variety of tapping
methods depending on the accessibility of sampling the
noise source. The sampled noise is then filtered by a
bandpass filter that has the same bandwidth as the
victim receive band. It may be possible to eliminate this
filter stage. However, this is dependent on the
characteristics of the aggressor source, the sampling
methodology and the location of the cancellation node
within the receiver chain. The QHx220 has internal LNA
gain stages that can be set to pre-amplify the sampled
input noise if necessary. The amount of pre-amplification
required (if any) depends on coupling factors between
the noise source and the victim antenna as well as the
level of the sampled noise at the input of the QHx220.
Since the dynamic range of the QHx220 is typically 50dB,
the noise level at the input of the QHx220 should be
approximately 25dB higher than the noise level present
at the victim receiver (when using the minimum gain
setting). Higher gain settings should be used when it is
not possible to find a strong enough tapping point of the
noise source. Setting this level correctly will allow for a
maximum tuning range when using the QHx220 tuning
control. This characterization will determine the amount
of pre-amplification necessary for any given application.
It is important to remember not to exceed the -45dBm
maximum input power of the QHx220 device. The
QHx220 has a high output impedance which only
introduces, on the order of tenths of a dB, insertion loss
FIGURE 1. TYPICAL APPLICATION DIAGRAM
SAMPLER
CANCELLATION
NODE
COUPLING CHANNEL
VICTIM
ANTENNA
NOISE SOURCE
SIGNAL INTEGRITY
VIA SPI BUS
VICTIM
RECEIVER
AND
BASEBAND
PARAMETER FEEDBACK
FC FC
QHx220
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to the victim receiver path. It taps the victim receive
path directly.
The QHx220 evaluation platform is an open loop system,
meaning that the optimization is performed manually.
With the addition of a microcontroller and some kind of
signal quality parameter fed back from the victim
receiver such as C/N, BER, RSSI, etc., the system can
operate closed loop. A simple algorithm can be coded to
optimize the gain and phase of the cancellation signal
based on the previous state of the quality parameter
provided by the victim receiver. Seed values can also be
used to improve the initial starting point state for the
optimization algorithm. Thus minimizing the number of
iterations required to achieve convergence. A look-up
table could also be implemented for systems operating
on multiple channel frequencies, but this may not be
necessary for extremely narrow band applications.
Essential Factors to Integrating the QHx220
Device into Your System
The purpose of this section is to provide some design
guidelines to ensure the successful integration of the
QHx220 into your system.
1. DO NOT exceed approximately -45dBm (exact limits
are specified within the datasheet depending on
frequency band) maximum input power of the
QHx220 device.
2. The sampled noise must be the same noise
(correlated with) as the noise that aggresses the
victim antenna. The amount of correlation is
proportional to the amount of cancellation that can
be achieved using the QHx220 device. It is often
necessary to try multiple tapping points and tapping
methods in order to achieve the best possible
correlation to the noise present in the victim
antenna.
3. Be sure to choose the correct level of pre-amplification
as described in the previous sections. If this is not
set correctly, it will limit the tuning range of the
QHx220 device and hence limit the amount of
cancellation that it is possible to achieve.
4. The delay from the noise source to the cancellation
node (via the coupling channel) should be matched
with the delay of noise source to the cancellation
node (via the sampler path). The main source of
mismatched delay is often due to the filter in the
receiver path. Using the same filter in the sampler
path is often a simple means of achieving sufficient
matching of the delay of both paths. One could also
move the cancellation node to precede the filter in
the receive path and eliminate the filter in the
sampler path. This could have drawbacks in some
applications depending on the out-of-band noise
characteristics and the noise sampling method
used.
5. The high impedance RF output of the QHx220
devices must be placed <5mm from the cancellation
node (the tapping point of the victim receiver),
otherwise resonances can occur that will attenuate
the cancellation signal. Figure 2 shows the effect of
varying the distance “L” between the QHx220 output
and the tapping point of the victim receiver.
FIGURE 2. DISTANCE FROM CANCELLATION NODE vs FREQUENCY
VICTIM ANTENNA
TO RADIO FREQUENCY (GHz)
dB (S(2, 1))
-5
-10
-15
-20
-25
0
0 0.5 1.0 1.5 2.0 2.5 3.0
L = 10mm
L = 5mm
L = 20mm
L = 25mm
L = 15mm
1516 14 13
12
10
9
11
6578
QHx
1
3
4
2
L
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Connecting the QHx220 Evaluation Board to
a PC for Manual Control
The Basic I-Q Control Software User Guide (AN1563)
provides a detailed description of how to install the
software GUI program that is used to manually control
the QHx220 evaluation board. The software should be
installed prior to connecting the hardware to the PC. The
Basic I-Q Control Software User Guide (AN1563) also
provides detailed instruction on how to configure all the
software settings required to control the frequency band,
gain, and gain and phase of the device. Please note that
the evaluation boards are populated to operate in a
specific frequency band. A tank circuit and matching
components are specifically chosen for each desired band
of operation. If a different frequency band is chosen via
the software GUI, then the QHx220 board should be
reconfigured accordingly. The correct BOM for MTV, GPS,
and WLAN frequency bands can be found in the
subsequent sections of this user guide.
A USB controller board plugs into the USB port of the PC
and is used to control the SPI bus interface of the
QHx220 device. The USB controller board also has a 1.8V
regulated supply that is used to power the QHx220
device. The user may alternatively power the device with
an external power supply if so desired. A custom cable is
also provided which is keyed so that it plugs into the USB
controller board in the correct orientation. Figure 3 shows
the USB controller board and cable connection.
The opposite end of the cable plugs into the QHx220
evaluation board to provide the 1.8V power supply
voltage and SPI connection to control the device. These
connectors are not “keyed” so please be sure that they
are oriented correctly. There are markings on the socket
and plug of each connector to identify the correct
orientation. Figure 4 shows these markings and the
orientation of the cable connections.
Three Hirose to SMA cables are provided for all of the RF
connections (Noise Sampler Input and Rx Input/Output).
FIGURE 3. THE QHx220 USB CONTROLLER BOARD
FIGURE 4. QHx220 USB CONTROLLER BOARD WITH PARTS LABELED
1.8V
INPUT
LED
NOISE SAMPLER
INPUT
Rx INPUT
(FROM ANTENNA)
Rx OUTPUT
(TO RECEIVER)
INTERSIL
QHX220
SPI
INTERFACE
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MTV Product Application
The following is a general overview on how the QHx220 can be applied for use in Mobile TV product applications.
QHx220 Board Layout
SPI INTERFACE
NOISE
SAMPLER
INPUT
INTERSIL
QHx220
1.8V INPUT
Rx INPUT
(FROM ANTENNA)
Rx OUTPUT
(TO RECEIVER)
GND
LED
FIGURE 5. QHx220 EVALUATION BOARD LAYOUT (MTV)
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QHx220 Board Schematics (for MTV)
FIGURE 6. SCHEMATIC OF QHx220 EVALUATION BOARD (MTV)
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QHx220 Board Bill of Materials (for MTV)
MTV Optimization Setup (Static Coupling
Channel)
The following sections explain how to set up a static
coupling channel which is used to perform self
cancellation. The test setup in the following section is a
useful environment to become familiar with tuning the
device to the desired frequency the user would like to
cancel in the final application. It will also provide an
intuitive means of obtaining the starting I and Q values
for achieving cancellation in the MTV Application setup.
A network analyzer is used to show the frequency
response of the QHx220 while performing the
optimization to achieve cancellation. It is suggested to
perform the following setup of the network analyzer
before connecting it to the rest of the test setup.
1. Set the desired frequency bandwidth for the
application.
2. Change the output power to -45dBm. This provides
some margin for the -45dBm maximum input
requirement of the QHx220 since there is an
additional 6dB loss from the power splitter. However,
if pre-amplification is used (operating in high gain or
boost mode) then the power should be reduced an
additional 10dB to 15dB per gain stage.
3. Perform a 2-port calibration of the network analyzer.
4. Select the S21 measurement mode.
The power splitter connected to the output of the
network analyzer is used to divide the aggressor signal
into two separate paths. One path goes to the sampler
input of the QHx220 which samples the aggressor signal.
The other path is fed to what will later be used as part of
the receive path for the MTV receiver. An attenuator pad
is used in this path to set the coupling losses. This loss
represents the coupling loss between the aggressor
source and the MTV victim antenna. For the purpose of
this evaluation the attenuator should be roughly 10dB to
20dB for a typical coupling factor. Keep in mind that the
second power splitter adds an additional 6dB to the
coupling factor. Since the QHx220 has ~50dB dynamic
range, this range of attenuation should set the aggressor
power in the middle of the tuning range of the QHx220
when using the lowest gain setting of the QHx220.
Higher gain settings can be used for stronger coupling
factors or weaker noise sampling or tapping methods.
It is important to set the power level of the network
analyzer to -45dBm. This will ensure that the sampler
input maximum power level is not exceeded. The
TABLE 1. QHx220 MTV-SPECIFIC EVALUATION BOARD BILL OF MATERIALS
ITEM QTY REFERENCE PART VENDOR VENDOR PART # DISTRIBUTOR
1 3 C0, C2, C5 100pF KEMET C0402C101J3GACTU Digikey_399_1022_1_ND
2 2 C3, C4 10nF KEMET C0402C103K3RACTU Digikey_399_1278_1_ND
3 2 C1 2pF Panasonic ECJ-0EC1H020C Digikey_PCC020CQCT
4 1 C6 22pF Murata GRM0335C1E220JD01D Digikey_490-1253-1-ND
51 C7 DNP
6 1 L0 39nH Panasonic ELJ-RE39NJF2 Digikey_PCD1158CT
7 1 L1 22nH Panasonic ELJ-RE22NJF2 Digikey_PCD1155CT
8 1 L3 10nH Panasonic ELJ-RE10NJF2 Digikey_PCD1151CT
9 2 L2, L8 100nH Panasonic ELJ-RER10JF3 Digikey_PCD1201CT-ND
10 1 L4 DNP
11 2 L5, L7 (L or R) 10kΩYageo 9C04021A1001FLHF3 Digikey_311-1.00KLCT-ND
12 1 L6 (L or R) 14kΩYageo RC0402FR-0714KL Digikey_311-14KLRCT
13 1 D1 LED Lumex SML_LXT0805GW Digikey_67_1553_1_ND
14 1 JP1 HD1x4 Waldom 87758_0416 Digikey_WM18833_ND
15 1 JP2 HD1x2 Waldom 22_28_4040 Digikey_WM6404_ND
16 3 J1, J2, J3 Hirose Digikey_H9161-ND
17 1 R0 DNP
18 1 R1 10ΩYageo 9C04021A10RFLHF3 Digikey_311-10.0LCT-ND
19 1 R2 220ΩROHM RC04022FR-07220RL Digikey_311-220LRCT-ND
20 3 R3, R4, R5 14kΩROHM RC04022FR-0714KL
21 1 U1 QNX220 Intersil QNX220
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measurement of interest is S21 in order to optimize the
MTV aggressor cancellation. Once the “MTV Optimization
Setup (Static Coupling Channel)” is ready, use the
software provided to configure the device as previously
described.
1. Select the MTV 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 8 is an example of the type of cancellation that
should be achieved when the I and Q values have been
optimized.
Once the cancellation has been optimized, record the I
and Q values for the optimization of the setup used.
FIGURE 7. MTV OPTIMIZATION SETUP DIAGRAM
ATTENUATOR PAD
TO SET COUPLING LOSS
MTV AGGRESSOR
NETWORK
ANALYZER
QHx220
CANCELLATION
NODE
POWER
SPLITTER
PORT 1 PORT 2
50Ω
TERMINATION
POWER
SPLITTER
PATH
FIGURE 8. EXAMPLE OF OPTIMUM CANCELLATION (MTV)
-35
-30
-25
-20
-15
-10
-5
0
400 420 440 460 480 500 520 540 560 580 600
FREQUENCY (MHz)
AFTER CANCELLATION
BEFORE CANCELLATION
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MTV Application Setup
The following setup should be used for testing QHx220
noise cancellation ability for a MTV application. It is
important to maintain the identical core setup used in the
“MTV Optimization Setup (Static Coupling Channel)”
section on page 7. Otherwise, the optimization values will
not be valid.
Begin with the aggressor source (signal generator) and
QHx220 board powered off. Turn on the MTV generator
and MTV tuner and record the receiver’s signal quality
parameters (C/N, BER, etc.) once a channel synch is
achieved. Find the weakest MTV generator level that will
still enable the tuner to maintain synchronization. Next,
set the aggressor signal generator to the same channel
frequency and set the power level to roughly 10dB above
the peak of the broadcast MTV signal. The aggressor
signal needs to be high enough to show degradation of
the receive signal strength reported by the MTV receiver.
Remember not to exceed ~ -45dBm at the input of the
QHx220. Once an aggressor power level is found that
degrades the receive signal strength reported by the MTV
receiver, turn on the QHx220 board and set the
optimized I and Q values that were determined in the
“MTV Optimization Setup (Static Coupling Channel)”
section on page 7. This should result in a <15dB
recovery of the receive signal strength power reported by
the MTV receiver if the board was optimized correctly.
However, since the setup was slightly modified from the
original optimization setup, it should be possible to fine
tune the QHx220 to improve the in-band noise
cancellation. Please note that any changes to the cable
lengths or slight impedance changes will slightly impact
the optimal gain and phase of the QHx220. Therefore, in
the MTV application setup, adjust the gain and/or phase
one step at a time and monitor the MTV receiver
sensitivity (or any other signal quality parameter (i.e.
C/N, BER, etc.). Continue to adjust the gain and phase
one step at a time until no further improvement to the
receiver sensitivity can be achieved.
FIGURE 9. MTV TESTING SETUP DIAGRAM
MTV
AGGRESSOR
PATH
MTV
GENERATOR
QHx220
MTV
TUNER
CANCELLATION
NODE
MTV RECEIVE PATH
POWER
SPLITTER
ATTENUATOR PAD
TO SET COUPLING LOSS
POWER
SPLITTER
AGGRESSOR
GENERATOR
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GPS Product Application
The following is a general overview on how the QHx220 can be applied for use in GPS product applications.
QHx220 Board Layout
SPI INTERFACE
INTERSIL
QHx220
1.8V INPUT
Rx INPUT
(FROM ANTENNA)
Rx OUTPUT
(TO RECEIVER)
GND
LED
NOISE
SAMPLER
INPUT
FIGURE 10. QHx220 EVALUATION BOARD LAYOUT (GPS)
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QHx220 Board Schematics (for GPS)
C
C
G1
G1
G2
G2
A
A
J1
C
C
G1 G1
G2
G2
A
A
J2
C
C
G1
G1
G2
G2
A
A
J3
L0
L_Select
C0
100pF
L8, 100nH
L1
L_Select
C3
10nF
C1
C_Select
C2
100pF
R1
R_ Select
GND1
1V8
GND1
C4
10nF
GND1
1V8
L2
100nH
C5
100pF
D1
LED
R2
220
1V8
GND1
GND2
GND1
C6
C_Select
L3
L_Select
GND1
L4
L_Option
C7
C_Option
GND1
1V8
R0
DNI
1
2
JP1
1
2
3
4
JP2
SPI
L7
10k
L6
14k
L5
10k
R5
14k
R4
14k
R3
14k
GND1 GND1
GND1
QHx220
GND1
1
GND1
3
IN
2
ENBAR
4
VDDD
5
CLK
6
DATA
7
EXTR
8
BUS 9
GND2 10
RF 11
GND2 12
VDDA 13
VDDA 14
IND 15
GND2 16
U1
FIGURE 11. SCHEMATIC OF QHx220 EVALUATION BOARD (GPS)
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12 July 6, 2010
AN1559.0
QHx220 Board Bill of Materials (for GPS)
GPS Optimization Setup (Static Coupling
Channel)
The following sections explain how to set up a static
coupling channel which is used to perform self
cancellation. The test setup in the following section is a
useful environment to become familiar with tuning the
device to the desired frequency the user would like to
cancel in the final application. It will also provide an
intuitive means of obtaining the starting I and Q values
for achieving cancellation in the GPS Application setup.
A network analyzer is used to show the frequency
response of the QHx220 while performing the
optimization to achieve cancellation. It is suggested to
perform the following setup of the network analyzer
before connecting it to the rest of the test setup.
1. Set the desired frequency bandwidth for the
application.
2. Change the output power to -45dBm. This provides
some margin for the -45dBm maximum input
requirement of the QHx220 since there is an
additional 6dB loss from the power splitter.
However, if pre-amplification is used (operating in
high gain or boost mode) then the power should be
reduced an additional 10dB to 15dB per gain stage.
3. Perform a 2 port calibration of the network analyzer.
4. Select the S21 measurement mode.
The power splitter connected to the output of the
network analyzer is used to divide the aggressor signal
into two separate paths. One path goes to the sampler
input of the QHx220 which samples the aggressor signal.
The other path is fed to what will later be used as part of
the receive path for the GPS receiver. An attenuator pad
is used in this path to set the coupling losses. This loss
represents the coupling loss between the aggressor
source and the GPS victim antenna. For the purpose of
this evaluation the attenuator should be roughly 10dB to
20dB for a typical coupling factor. Keep in mind that the
second power splitter adds an additional 6dB to the
coupling factor. Since the QHx220 has ~50dB dynamic
range, this range of attenuation should set the aggressor
power in the middle of the tuning range of the QHx220
when using the lowest gain setting of the QHx220.
Higher gain settings can be used for stronger coupling
factors or weaker noise sampling or tapping methods.
It is important to set the power level of the network
analyzer to -45dBm. This will ensure that the sampler
input maximum power level is not exceeded. The
measurement of interest is S21 in order to optimize the
TABLE 2. QHx220 GPS-SPECIFIC EVALUATION BOARD BILL OF MATERIALS
ITEM QTY REFERENCE PART VENDOR VENDOR PART # DISTRIBUTOR
1 3 C0, C2, C5 100pF KEMET C0402C101J3GACTU Digikey_399_1022_1_ND
2 2 C3, C4 10nF KEMET C0402C103K3RACTU Digikey_399_1278_1_ND
31 C1 DNP
4 1 C6 22pF Murata GRM0335C1E220JD01D Digikey_490-1253-1-ND
5 1 C7 DNP
6 1 L0 6.2nH MURATA LQG15HS6N2SO2D Digikey_490-2620-1
7 1 L1 5.6nH Panasonic ELJ-RE5N6JF2 Digikey_PCD1148CT
8 1 L3 0.0ΩROHM MCR01MZPJ000 Digikey_rhm0.0JCT-ND
9 2 L2, L8 100nH Panasonic ELJ-RER10JF3 Digikey_PCD1201CT-ND
10 1 L4 DNP
11 2 L5, L7 (L or R) 10kΩYageo 9C04021A1001FLHF3 Digikey_311-1.00KLCT-ND
12 1 L6 (L or R) 14kΩYageo RC0402FR-0714KL Digikey_311-14KLRCT
13 1 D1 LED Lumex SML_LXT0805GW Digikey_67_1553_1_ND
14 1 JP1 HD1x4 Waldom 87758_0416 Digikey_WM18833_ND
15 1 JP2 HD1x2 Waldom 22_28_4040 Digikey_WM6404_ND
16 3 J1, J2, J3 Hirose Digikey_H9161-ND
17 1 R0 DNP
18 1 R1 DNP
19 1 R2 220ΩROHM RC04022FR-07220RL Digikey_311-220LRCT-ND
20 3 R3, R4, R5 14kΩROHM RC04022FR-0714KL Digikey_311-14.0KLRCT
21 1 U1 QNX220 Intersil QNX220
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GPS aggressor cancellation. Once the “GPS Optimization
Setup (Static Coupling Channel)” is ready, use the
software provided to configure the device as previously
described.
1. Select the GPS 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 13 is an example of the type of cancellation that
should be achieved when the I and Q values have been
optimized.
Once the cancellation has been optimized, record the I
and Q values for the optimization of the setup used.
ATTENUATOR PAD
TO SET COUPLING LOSS
GPS AGGRESSOR
NETWORK
ANALYZER
QHX220
CANCELLATION
NODE
POWER
SPLITTER
PORT 1 PORT 2
POWER
SPLITTER
50Ω
TERMINATION
PATH
FIGURE 12. GPS OPTIMIZATION SETUP DIAGRAM
FIGURE 13. EXAMPLE OF OPTIMUM CANCELLATION (GPS)
-80
-70
-60
-50
-40
-30
1400 1450 1500 1550 1600 1650 1700
FREQUENCY (MHz)
AFTER CANCELLATION
BEFORE CANCELLATION
GPS BAND
COUPLING CHANNEL (dB)
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GPS Application Setup
The following setup should be used for testing QHx220
noise cancellation ability for a GPS application. It is
important to maintain the identical core setup used in the
“GPS Optimization Setup (Static Coupling Channel)”
section on page 12. Otherwise, the optimization values
will not be valid.
Begin with the aggressor source (signal generator) and
QHx220 board powered off. Turn on the GPS simulator
and GPS receiver and record the receiver’s signal quality
parameters (C/N, etc.) once a satellite lock is achieved.
Find the weakest GPS signal power level that will still
maintain a lock. Next, set the aggressor signal generator
to the same GPS frequency and set the power level to
roughly 10dB above the peak of the broadcast GPS
signal. The aggressor signal needs to be high enough to
show degradation of the receive signal strength reported
by the GPS receiver. Remember not to exceed ~ -45dBm
at the input of the QHx220. Once an aggressor power
level is found that degrades the receive signal strength
reported by the GPS receiver, turn on the QHx220 board
and set the optimized I and Q values that were
determined in the “GPS Optimization Setup (Static
Coupling Channel)” section on page 12. This should
result in a <15dB recovery of the receive signal strength
power reported by the GPS receiver if the board was
optimized correctly. However, since the setup was slightly
modified from the original optimization setup, it should
be possible to fine tune the QHx220 to improve the
in-band noise cancellation. Please note that any changes
to the cable lengths or slight impedance changes will
slightly impact the optimal gain and phase of the
QHx220. Therefore, in the GPS application setup, adjust
the gain and/or phase one step at a time and monitor the
GPS receiver sensitivity (or any other signal quality
parameter (i.e. C/N, etc.). Continue to adjust the gain
and phase one step at a time until no further
improvement to the receiver sensitivity can be achieved.
FIGURE 14. GPS TESTING SETUP DIAGRAM
GPS
AGGRESSOR
PATH
SIGNAL
GENERATOR
GPS
SIMULATOR
QHX220
GPS
TUNER
CANCELLATION
NODE
GPS RECEIVE PATH
POWER
SPLITTER
ATTENUATOR PAD
TO SET COUPLING LOSS
POWER
SPLITTER
Application Note 1559

15 July 6, 2010
AN1559.0
WLAN Product Application
The following is a general overview on how the QHx220 can be applied for use in WLAN product applications.
QHx220 Board Layout
SPI INTERFACE
INTERSIL
QHX220
1.8V INPUT
Rx INPUT
(FROM ANTENNA)
Rx OUTPUT
(TO RECEIVER)
GND
LED
NOISE
SAMPLER
INPUT
FIGURE 15. QHx220 EVALUATION BOARD LAYOUT (WLAN)
Application Note 1559

16 July 6, 2010
AN1559.0
QHx220 Board Schematics (for WLAN)
C
C
G1
G1
G2
G2
A
A
J1
C
C
G1 G1
G2 G2
A
A
J2
C
C
G1 G1
G2 G2
AA
J3
L0
L_Select
C0
100pF
L8, 100nH
L1
L_Select
C3
10nF
C1
C_Select
C2
100pF
R1
R_Select
GND1
1V8
GND1
C4
10nF
GND1
1V8
L2
100nH
C5
100pF
D1
LED
R2
220
1V8
GND1
GND2
GND1
C6
C_Select
L3
L_Select
GND1
L4
L_Option
C7
C_Option
GND1
1V8
R0
DNI
1
2
JP1
1
2
3
4
JP2
SPI
L7
10k
L6
14k
L5
10k
R5
14k R4 14k
R3
14k
GND1 GND1
GND1
QHX2 20
GND1
1
GND1
3
IN
2
ENBAR
4
VDDD
5
CLK
6
DATA
7
EXTR
8
BUS 9
GND2
10
RF
11
GND2
12
VDDA 13
VDDA 14
IND 15
GND2 16
U1
FIGURE 16. SCHEMATIC OF QHx220 EVALUATION BOARD (WLAN)
Application Note 1559

17 July 6, 2010
AN1559.0
QHx220 Board Bill of Materials (for WLAN)
WLAN Optimization Setup (Static Coupling
Channel)
The following sections explain how to set up a static
coupling channel which is used to perform self
cancellation. The test setup in the following section is a
useful environment to become familiar with tuning the
device to the desired frequency the user would like to
cancel in the final application. It will also provide an
intuitive means of obtaining the starting I and Q values
for achieving cancellation in the WLAN Application setup.
A network analyzer is used to show the frequency
response of the QHx220 while performing the
optimization to achieve cancellation. It is suggested to
perform the following setup of the network analyzer
before connecting it to the rest of the test setup.
1. Set the desired frequency bandwidth for the
application.
2. Change the output power to -45dBm. This provides
some margin for the -45dBm maximum input
requirement of the QHx220 since there is an
additional 6dB loss from the power splitter. However
if pre-amplification is used (operating in high gain or
boost mode) then the power should be reduced an
additional 10dB to 15dB per gain stage.
3. Perform a 2 port calibration of the network analyzer.
4. Select the S21 measurement mode.
The power splitter connected to the output of the
network analyzer is used to divide the aggressor signal
into two separate paths. One path goes to the sampler
input of the QHx220 which samples the aggressor signal.
The other path is fed to what will later be used as part of
the receive path for the WLAN receiver. An attenuator
pad is used in this path to set the coupling losses. This
loss represents the coupling loss between the aggressor
source and the WLAN victim antenna. For the purpose of
this evaluation the attenuator should be roughly 10dB to
20dB for a typical coupling factor. Keep in mind that the
second power splitter adds an additional 6dB to the
coupling factor. Since the QHx220 has ~50dB dynamic
range, this range of attenuation should set the aggressor
power in the middle of the tuning range of the QHx220
when using the lowest gain setting of the QHx220.
Higher gain settings can be used for stronger coupling
factors or weaker noise sampling or tapping methods.
It is important to set the power level of the network
analyzer to -45dBm. This will ensure that the sampler
input maximum power level is not exceeded. The
measurement of interest is S21 in order to optimize the
TABLE 3. QHx220 WLAN-SPECIFIC EVALUATION BOARD BILL OF MATERIALS
ITEM QTY REFERENCE PART VENDOR VENDOR PART # DISTRIBUTOR
1 3 C0, C2, C5 100pF KEMET C0402C101J3GACTU Digikey_399_1022_1_ND
2 2 C3, C4 10nF KEMET C0402C103K3RACTU Digikey_399_1278_1_ND
31 C1 DNP
41 C6 0.0ΩPanasonic ERJ-1GE0R00C Digikey_P0.0AGCT-ND
51 C7 DNP
6 1 L0 3.3nH Panasonic ELJ-RE3N3DF2 Digikey_PCD1145CT
7 1 L1 1.5nH Panasonic ELJ-RE1N5DF2 Digikey_PCD1196CT
81 L3 0.0ΩROHM MCR01MZPJ000 Digikey_RHM0.0JCT_ND
9 2 L2, L8 100nH Panasonic ELJ-RER10JF3 Digikey_PCD1201CT-ND
10 1 L4 DNP
11 2 L5, L7 (L or R) 10kΩYageo 9C04021A1001FLHF3 Digikey_311-1.00KLCT-ND
12 1 L6 (L or R) 14kΩYageo RC0402FR-0714KL Digikey_311-14KLRCT
13 1 D1 LED Lumex SML_LXT0805GW Digikey_67_1553_1_ND
14 1 JP1 HD1x4 Waldom 87758_0416 Digikey_WM18833_ND
15 1 JP2 HD1x2 Waldom 22_28_4040 Digikey_WM6404_ND
16 3 J1, J2, J3 Hirose Digikey_H9161-ND
17 1 R0 DNP
18 1 R1 DNP
19 1 R2 220ΩROHM RC04022FR-07220RL Digikey_311-220LRCT-ND
20 3 R3, R4, R5 14kΩROHM RC04022FR-0714KL Digikey_311-14.0KLRCT
21 1 U1 QNX220 Intersil QNX220
Application Note 1559

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
50Ω
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

19
Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the
reader is cautioned to verify that the Application Note or Technical Brief is current before proceeding.
For information regarding Intersil Corporation and its products, see www.intersil.com
July 6, 2010
AN1559.0
WLAN Application Setup
The following setup should be used for testing QHx220
noise cancellation ability for a WLAN application. It is
important to maintain the identical core setup used in the
“WLAN Optimization Setup (Static Coupling Channel)”
section on page 17. Otherwise, the optimization values
will not be valid.
Begin with the aggressor source (signal generator) and
QHx220 board powered off. Turn on the WLAN simulator
and WLAN receiver and record the receiver’s signal
quality parameters (C/N, etc.). Find the weakest WLAN
signal power level that will still maintain a WLAN link.
Next set the aggressor signal generator to the same
WLAN frequency and set the power level to roughly 10dB
above the peak of the broadcast WLAN signal. The
aggressor signal needs to be high enough to show
degradation of the receive signal strength reported by
the WLAN receiver. Remember not to exceed ~ -45dBm
at the input of the QHx220. Once an aggressor power
level is found that degrades the receive signal strength
reported by the WLAN receiver, turn on the QHx220
board and set the optimized I and Q values that were
determined in the “WLAN Optimization Setup (Static
Coupling Channel)” section on page 17. This should
result in a <15dB recovery of the receive signal strength
power reported by the WLAN receiver if the board was
optimized correctly. However, since the setup was slightly
modified from the original optimization setup, it should
be possible to fine tune the QHx220 to improve the
in-band noise cancellation. Please note that any changes
to the cable lengths or slight impedance changes will
slightly impact the optimal gain and phase of the
QHx220. Therefore, in the WLAN application setup,
adjust the gain and/or phase one step at a time and
monitor the WLAN receiver sensitivity (or any other
signal quality parameter (i.e. C/N, etc.). Continue to
adjust the gain and phase one step at a time until no
further improvement to the receiver sensitivity can be
achieved.
Q:ACTIVE
Q:ACTIVE Technology is behind Intersil’s ability to insert
its ICs inside radios, automotive infotainment systems,
satellite broadcast equipment, and various consumer
electronic devices such as GPS units, cell phones, and
portable gaming systems. By doing so, Intersil achieves
the ability to reduce electromagnetic interference by as
much as 30dB. This breakthrough in radio sensitivity
allows for several signals to run simultaneously and
enables new technologies such as mobile TV on hand
held games, cell phones, and in automotive systems.
FIGURE 19. WLAN TESTING SETUP DIAGRAM
WLAN
AGGRESSOR
PATH
SIGNAL
GENERATOR
WLAN
SIMULATOR
QHX220
WLAN
RECEIVER
CANCELLATION
NODE
WLAN RECEIVE PATH
POWER
SPLITTER
ATTENUATOR PAD
TO SET COUPLING LOSS
POWER
SPLITTER
Application Note 1559

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Authorized Distributor
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