1. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Characterizing an S-band Marine Radar
Receiver in the Presence of Interference
Mark McFarland, P.E.
Dr. Bob Johnk
U.S. Department of Commerce
National Telecommunications and Information Administration
Institute for Telecommunications Sciences
2012 IEEE International Symposium on EMC
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
2. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Outline
What You’ll Learn:
Potential interference risk
between BRS signals and
S-band radar receivers
Our measurement system
enables simple, automated
characterization of interference
effects
Without need for a NLNA
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
3. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Outline
1 Motivation
Why?
Interference Considerations
2 Acquiring AM-AM/PM Characteristics
Overview
Non-linear Network Analysis
3 DiY Non-linear Network Analyzer
Measurement System
Calibration & Processing
4 Results
Insertion Loss
Insertion Phase
Comparison
5 Summary
What You’ll Learn:
Potential interference risk
between BRS signals and
S-band radar receivers
Our measurement system
enables simple, automated
characterization of interference
effects
Without need for a NLNA
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
5. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Why Are We Studying This?
Potential Interference Risk
Broadband radio service (BRS) spectrum allocations may
interfere with S-band marine radars
BRS includes Wi-MAX and LTE
∼50% of US population located within a few miles of coasts
Number of those people using BRS systems increasing!
US Coast Guard seeking to develop Interference Protection
Criteria for S-band marine radars
Over a range of interferer power levels & frequencies, we want
to understand:
Radar receiver’s AM-AM/PM characteristics
Gain compression and changes in noise statistics due to BRS
signals
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
6. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Why Are We Studying This?
Potential Interference Risk
Broadband radio service (BRS) spectrum allocations may
interfere with S-band marine radars
BRS includes Wi-MAX and LTE
∼50% of US population located within a few miles of coasts
Number of those people using BRS systems increasing!
US Coast Guard seeking to develop Interference Protection
Criteria for S-band marine radars
Over a range of interferer power levels & frequencies, we want
to understand:
Radar receiver’s AM-AM/PM characteristics
Gain compression and changes in noise statistics due to BRS
signals
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
7. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Why Are We Studying This?
Potential Interference Risk
Broadband radio service (BRS) spectrum allocations may
interfere with S-band marine radars
BRS includes Wi-MAX and LTE
∼50% of US population located within a few miles of coasts
Number of those people using BRS systems increasing!
US Coast Guard seeking to develop Interference Protection
Criteria for S-band marine radars
Over a range of interferer power levels & frequencies, we want
to understand:
Radar receiver’s AM-AM/PM characteristics
Gain compression and changes in noise statistics due to BRS
signals
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
8. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Why Are We Studying This?
Potential Interference Risk
Broadband radio service (BRS) spectrum allocations may
interfere with S-band marine radars
BRS includes Wi-MAX and LTE
∼50% of US population located within a few miles of coasts
Number of those people using BRS systems increasing!
US Coast Guard seeking to develop Interference Protection
Criteria for S-band marine radars
Over a range of interferer power levels & frequencies, we want
to understand:
Radar receiver’s AM-AM/PM characteristics
Gain compression and changes in noise statistics due to BRS
signals
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
9. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Why Are We Studying This?
Potential Interference Risk
Broadband radio service (BRS) spectrum allocations may
interfere with S-band marine radars
BRS includes Wi-MAX and LTE
∼50% of US population located within a few miles of coasts
Number of those people using BRS systems increasing!
US Coast Guard seeking to develop Interference Protection
Criteria for S-band marine radars
Over a range of interferer power levels & frequencies, we want
to understand:
Radar receiver’s AM-AM/PM characteristics
Gain compression and changes in noise statistics due to BRS
signals
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
10. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Why Are We Studying This?
Potential Interference Risk
Broadband radio service (BRS) spectrum allocations may
interfere with S-band marine radars
BRS includes Wi-MAX and LTE
∼50% of US population located within a few miles of coasts
Number of those people using BRS systems increasing!
US Coast Guard seeking to develop Interference Protection
Criteria for S-band marine radars
Over a range of interferer power levels & frequencies, we want
to understand:
Radar receiver’s AM-AM/PM characteristics
Gain compression and changes in noise statistics due to BRS
signals
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
11. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Why Are We Studying This?
Potential Interference Risk
Broadband radio service (BRS) spectrum allocations may
interfere with S-band marine radars
BRS includes Wi-MAX and LTE
∼50% of US population located within a few miles of coasts
Number of those people using BRS systems increasing!
US Coast Guard seeking to develop Interference Protection
Criteria for S-band marine radars
Over a range of interferer power levels & frequencies, we want
to understand:
Radar receiver’s AM-AM/PM characteristics
Gain compression and changes in noise statistics due to BRS
signals
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
12. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Why Are We Studying This?
Potential Interference Risk
Broadband radio service (BRS) spectrum allocations may
interfere with S-band marine radars
BRS includes Wi-MAX and LTE
∼50% of US population located within a few miles of coasts
Number of those people using BRS systems increasing!
US Coast Guard seeking to develop Interference Protection
Criteria for S-band marine radars
Over a range of interferer power levels & frequencies, we want
to understand:
Radar receiver’s AM-AM/PM characteristics
Gain compression and changes in noise statistics due to BRS
signals
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
13. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
S-band Radar Basics
S-band Frequencies (MHz)
Marine Band 2900-3100
Radar Channel 3020-3080
RF Input Frequency 3050
IF Output Frequency 60
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
14. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
S-band Radar Basics
S-band Frequencies (MHz)
Marine Band 2900-3100
Radar Channel 3020-3080
RF Input Frequency 3050
IF Output Frequency 60
Frequency (MHz)
Gain(dB)
−30
−25
−20
−15
−10
−5
0
2000 2500 3000 3500 4000
Component(s)
Circulator
Limiter
Circulator
and
Limiter
Band
Marine
Radar
Channel
BRS
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
15. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
S-band Radar Components
Photograph
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
16. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
S-band Radar Components
Photograph
Circulator
Limiter
LNFE
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
17. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
S-band Radar Components
Photograph
Circulator
RFin
Tx
(50 Ω load)
Limiter
LNFE
LOin
power
IFout
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
18. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
S-band Radar Components
Photograph
Circulator
RFin
Tx
(50 Ω load)
Limiter
LNFE
LOin
power
IFout
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
19. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Interference Considerations
Susceptibility
LNFE receivers (used in radar, also GPS)
Sensitive receivers
Multi-stage gain
“Wide-open” or filtered front ends
Probability of interference between radar & BRS signals
increasing
Contributors
WiMAX LTE Others?
Impact on LNFE Receivers
Analyzed via receiver’s AM-AM and AM-PM characteristics
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
21. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Overview
AM-AM and AM-PM
AM-AM Describes system’s output power over a range of
input power levels
AM-PM Describes system’s output phase over a range of
input power levels
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
22. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Overview
AM-AM and AM-PM
AM-AM Describes system’s output power over a range of
input power levels
AM-PM Describes system’s output phase over a range of
input power levels
Lots of Data Required for Characterization
15 interferer power levels
−50 to +20 dBm in 5 dB increments
8 interferer frequencies (2850-3250 MHz, 50 MHz steps)
15 × 8 = 120 baseline measurements
+ 120 RF cal measurements, + 15 IF cal measurements
TOTAL: 255 measurements (or VSA recordings)
Not a manual task!
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
23. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Overview
AM-AM and AM-PM
AM-AM Describes system’s output power over a range of
input power levels
AM-PM Describes system’s output phase over a range of
input power levels
Lots of Data Required for Characterization
15 interferer power levels
−50 to +20 dBm in 5 dB increments
8 interferer frequencies (2850-3250 MHz, 50 MHz steps)
15 × 8 = 120 baseline measurements
+ 120 RF cal measurements, + 15 IF cal measurements
TOTAL: 255 measurements (or VSA recordings)
Not a manual task!
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
24. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Overview
AM-AM and AM-PM
AM-AM Describes system’s output power over a range of
input power levels
AM-PM Describes system’s output phase over a range of
input power levels
Lots of Data Required for Characterization
15 interferer power levels
−50 to +20 dBm in 5 dB increments
8 interferer frequencies (2850-3250 MHz, 50 MHz steps)
15 × 8 = 120 baseline measurements
+ 120 RF cal measurements, + 15 IF cal measurements
TOTAL: 255 measurements (or VSA recordings)
Not a manual task!
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
25. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Overview
AM-AM and AM-PM
AM-AM Describes system’s output power over a range of
input power levels
AM-PM Describes system’s output phase over a range of
input power levels
Lots of Data Required for Characterization
15 interferer power levels
−50 to +20 dBm in 5 dB increments
8 interferer frequencies (2850-3250 MHz, 50 MHz steps)
15 × 8 = 120 baseline measurements
+ 120 RF cal measurements, + 15 IF cal measurements
TOTAL: 255 measurements (or VSA recordings)
Not a manual task!
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
26. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Overview
AM-AM and AM-PM
AM-AM Describes system’s output power over a range of
input power levels
AM-PM Describes system’s output phase over a range of
input power levels
Lots of Data Required for Characterization
15 interferer power levels
−50 to +20 dBm in 5 dB increments
8 interferer frequencies (2850-3250 MHz, 50 MHz steps)
15 × 8 = 120 baseline measurements
+ 120 RF cal measurements, + 15 IF cal measurements
TOTAL: 255 measurements (or VSA recordings)
Not a manual task!
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
27. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Overview
AM-AM and AM-PM
AM-AM Describes system’s output power over a range of
input power levels
AM-PM Describes system’s output phase over a range of
input power levels
Lots of Data Required for Characterization
15 interferer power levels
−50 to +20 dBm in 5 dB increments
8 interferer frequencies (2850-3250 MHz, 50 MHz steps)
15 × 8 = 120 baseline measurements
+ 120 RF cal measurements, + 15 IF cal measurements
TOTAL: 255 measurements (or VSA recordings)
Not a manual task!
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
28. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Non-linear Network Analysis
AM-AM/PM characteristics usually acquired with a network
analyzer
Not possible in this case due to frequency conversion
RF Input = 3050 MHz
IF Output = 60 MHz
Thus, non-linear network analysis is needed
How to Perform Non-linear Network Analysis?
With a non-linear network analyzer (NLNA)
A NLNA can measure output power and phase at one
frequency as a function of input power at a different frequency
Accommodates frequency conversion in the DUT
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
29. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Non-linear Network Analysis
AM-AM/PM characteristics usually acquired with a network
analyzer
Not possible in this case due to frequency conversion
RF Input = 3050 MHz
IF Output = 60 MHz
Thus, non-linear network analysis is needed
How to Perform Non-linear Network Analysis?
With a non-linear network analyzer (NLNA)
A NLNA can measure output power and phase at one
frequency as a function of input power at a different frequency
Accommodates frequency conversion in the DUT
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
30. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Non-linear Network Analysis
AM-AM/PM characteristics usually acquired with a network
analyzer
Not possible in this case due to frequency conversion
RF Input = 3050 MHz
IF Output = 60 MHz
Thus, non-linear network analysis is needed
How to Perform Non-linear Network Analysis?
With a non-linear network analyzer (NLNA)
A NLNA can measure output power and phase at one
frequency as a function of input power at a different frequency
Accommodates frequency conversion in the DUT
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
31. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Non-linear Network Analysis
AM-AM/PM characteristics usually acquired with a network
analyzer
Not possible in this case due to frequency conversion
RF Input = 3050 MHz
IF Output = 60 MHz
Thus, non-linear network analysis is needed
How to Perform Non-linear Network Analysis?
With a non-linear network analyzer (NLNA)
A NLNA can measure output power and phase at one
frequency as a function of input power at a different frequency
Accommodates frequency conversion in the DUT
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
32. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Non-linear Network Analysis
AM-AM/PM characteristics usually acquired with a network
analyzer
Not possible in this case due to frequency conversion
RF Input = 3050 MHz
IF Output = 60 MHz
Thus, non-linear network analysis is needed
How to Perform Non-linear Network Analysis?
With a non-linear network analyzer (NLNA)
A NLNA can measure output power and phase at one
frequency as a function of input power at a different frequency
Accommodates frequency conversion in the DUT
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
33. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Non-linear Network Analysis
AM-AM/PM characteristics usually acquired with a network
analyzer
Not possible in this case due to frequency conversion
RF Input = 3050 MHz
IF Output = 60 MHz
Thus, non-linear network analysis is needed
How to Perform Non-linear Network Analysis?
With a non-linear network analyzer (NLNA)
A NLNA can measure output power and phase at one
frequency as a function of input power at a different frequency
Accommodates frequency conversion in the DUT
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
34. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Tradeoffs
Problem
NLNAs cost ∼$250,000
Solution
Build a NLNA using:
commonly available lab
equipment
open source software
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
35. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Tradeoffs
Problem
NLNAs cost ∼$250,000
Solution
Build a NLNA using:
commonly available lab
equipment
open source software
Do-it-Yourself Non-linear Network Analyzer
VSG DUT VSA Processing
AM-AM
AM-PM
Rb clock
AutoHotkey Control
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
37. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Measurement System
Block Diagram
Radar System Components
VSG circ. limiter LNFE BPF VSA
Rb clock
LO
ControlAutoHotkey
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
38. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Measurement System
Block Diagram
Radar System Components
VSG circ. limiter LNFE BPF VSA
Rb clock
LO
ControlAutoHotkey
Provides interferer signal (varying frequency and power)
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
39. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Measurement System
Block Diagram
Radar System Components
VSG circ. limiter LNFE BPF VSA
Rb clock
LO
ControlAutoHotkey
Synchronizes VSG, VSA, and DUT (if applicable)
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
40. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Measurement System
Block Diagram
Radar System Components
VSG circ. limiter LNFE BPF VSA
Rb clock
LO
ControlAutoHotkey
Records IF output
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
41. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Measurement System
Block Diagram
Radar System Components
VSG circ. limiter LNFE BPF VSA
Rb clock
LO
ControlAutoHotkey
PC running VSA GUI control software
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
42. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Measurement System
Block Diagram
Radar System Components
VSG circ. limiter LNFE BPF VSA
Rb clock
LO
ControlAutoHotkey
AutoHotkey controls the VSA’s GUI
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
43. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Measurement System
Block Diagram
Radar System Components
VSG circ. limiter LNFE BPF VSA
Rb clock
LO
ControlAutoHotkey
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
44. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Measurement System
AutoHotkey Automation
Open source
GNU General Public License
No cost or license fees
Automate almost any computer task
Send keystrokes and/or mouse movements & clicks to
applications
Offers a scripting language
Simple
Low development time
Can monitor VSA GUI
See http://www.autohotkey.com
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
45. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Measurement System
AutoHotkey Automation - Sample Code
§ ¤
1 $F5::
prefix=in -band.3050
startPower = -50
stopPower = 20
6 dbStep = 5
numIter := (stopPower - startPower)/dbStep + 1
Loop %numIter%
{
11 power := startPower + dbStep *( a_index -1)
; STARTUP - Data from hardware , then restart
Send !ifh ; select: Input -dataFrom -Hardware
Sleep , 1000
16
Send !cr ; select: Control -Restart -- to restart measurement
Sleep , 8000 ; wait for filters ...
; START RECORDING
21 Send !cd ; start recording
Sleep , 10000 ; wait for filters to settle and recording to finish
; SAVE RECORDING
Send !fsr %prefix %.% power %{ Enter }{ Enter}
26
Sleep , 5000 ; wait for recording to write and VSG to change output power
}
¦ ¥
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
46. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Measurement System
Photograph
LO
Rb clock
VSG
AHK/control
VSA
not used
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
47. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Calibration & Processing
Block Diagrams
Baseline
Radar System Components
VSG circ. limiter LNFE BPF VSA
Rb clock
LO
ControlAutoHotkey
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
48. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Calibration & Processing
Block Diagrams
Baseline
Radar System Components
VSG circ. limiter LNFE BPF VSA
Rb clock
LO
ControlAutoHotkey
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
49. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Calibration & Processing
Block Diagrams
Baseline
Radar System Components
VSG circ. limiter LNFE BPF VSA
Rb clock
LO
ControlAutoHotkey
RF
VSG VSA
Rb clock
AutoHotkey Control
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
50. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Calibration & Processing
Block Diagrams
Baseline
Radar System Components
VSG circ. limiter LNFE BPF VSA
Rb clock
LO
ControlAutoHotkey
RF
VSG VSA
Rb clock
AutoHotkey Control
IF
VSG BPF VSA
Rb clock
AutoHotkey Control
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
52. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Insertion Loss
Interferer Power (dBm)
InsertionLoss(dB)
1
2
3
4
5
G G
G
G G G G G G
G
G
G
G
G
G
G G
G
G G
G G
G
G
G
G
G
G G
G
G G
G
G G
G G
G
G
G G G
G
G
G
−50 −40 −30 −20 −10 0 10 20
Frequency
(MHz)
3250
G 3200
3150
3100
3000
2950
G 2900
2850
G 60
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
53. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Insertion Phase
Interferer Power (dBm)
InsertionPhase(rad.)
−π
−
π
2
0
π
2
π
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G
G G
G
G
G
G
G
G
G
G
G
G
G
G
G
G G G G G G G G G G G
G
G
G
G
−50 −40 −30 −20 −10 0 10 20
Frequency
(MHz)
3250
G 3200
3150
3100
3000
2950
G 2900
2850
G 60
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
57. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
Summary
Potential interference risk between BRS signals and S-band
radar receivers
Can easily acquire AM-AM and AM-PM characteristics
Frequency conversion not a problem
NLNA not needed
DiY NLNA can be build using common lab equipment
AutoHotkey can automate the collection of data
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
58. Motivation Acquiring AM-AM/PM Characteristics DiY Non-linear Network Analyzer Results Summary
The End
THANK YOU!
McFarland, Johnk S-band Marine Radar Receiver in the Presence of Interference
