1. AIM4170 ANTENNA ANALYZER Part 1
Ian Wade, G3NRW
8 September 2011
Copyright © 2010,2011 Ian Wade
All Rights Reserved

2. AIM4170 Antenna Analyzer
PART INTRODUCING THE ANALYZER
Antenna impedance – what does it mean?
AIM4170 capabilities
Examples
PART USING THE ANALYZER AS A DESIGN TOOL
Designing a 160m/80m Trap Dipole
Measuring the Antenna Feedpoint Impedance
Remote AIM4170 Operation

3. AIM4170 PART 1 1: Introduction to the AIM4170
2: Some Basic Definitions
3: Impedance, Resistance and Reactance
4: Impedance at the Transmitter, Feeder and Antenna
5: AIM4170 Functions
6: Measuring Capacitance, Inductance and Resonance
7: Typical Antenna Scans
8: Some other AIM4170 Functions
9: The Smith Chart
10: Time Division Reflectometry (TDR) Mode

4. Live Demonstrations
Tuning a 70MHz groundplane
Measuring discrete components (L, C)
Tuning traps
Designing a 160m/80m trap dipole
Determining antenna feedpoint impedance
Conjugate matching in the ATU
Remote control of the AIM4170 via a WiFi link

5. AIM4170 PART 1 1: Introduction to the AIM4170
2: Some Basic Definitions
3: Impedance, Resistance and Reactance
4: Impedance at the Transmitter, Feeder and Antenna
5: AIM4170 Functions
6: Measuring Capacitance, Inductance and Resonance
7: Typical Antenna Scans
8: Some other AIM4170 Functions
9: The Smith Chart
10: Time Division Reflectometry (TDR) Mode

6. AIM4170 Network Analyzer from Array Solutions
Vector Mode
Single-port Vector Network Analyzer (VNA) measures impedance
Time Domain Reflectometry (TDR) Mode
measures time/distance

7. AIM4170 Vector Mode
Frequency Coverage: AIM4170B: 100kHz-180MHz AIM4170C: 5kHz-180MHz
Resistance and reactance: at the feeder input at the antenna feedpoint
Resistance, reactance and Q of discrete components
Return loss, reflection coefficient, SWR
Cable length, cable impedance, cable loss
Distance to fault (open or short), stub tuning
Smith chart display
Band scan for interfering signals
Quartz crystal parameters
Synthesized frequency source for receiver / filter testing
Software controlled
No internal calibration adjustments

8. AIM4170 Connection to the AntennaPC
AIM4170
AIM

9. AIM4170 Connection to the PC
AIM PC
running AIM software
RS232 Serial Link
to antenna under test

10. AIM4170 Front Panel

11. AIM4170 Rear Panel

12. AIM4170 Internal Construction

13. AIM4170 Input Protection Series relay – only closed when scanning
Gas discharge tube connected directly to ground
100K resistor connected directly to ground
Back-to-back silicon diodes in the measurement circuit
The input to the AIM is DC coupled, so be sure there is no DC control voltage present on the line

14. AIM4170 PART 1 1: Introduction to the AIM4170
2: Some Basic Definitions
3: Impedance, Resistance and Reactance
4: Impedance at the Transmitter, Feeder and Antenna
5: AIM4170 Functions
6: Measuring Capacitance, Inductance and Resonance
7: Typical Antenna Scans
8: Some other AIM4170 Functions
9: The Smith Chart
10: Time Division Reflectometry (TDR) Mode

15. Feedpoints
Antenna
Feedpoint
Feeder
Feeder
Feedpoint TX
ATU

16. Antenna System Antenna Feedpoint Antenna System Matching Feeder UnitTX
ATU

17. AIM4170 PART 1 1: Introduction to the AIM4170
2: Some Basic Definitions
3: Impedance, Resistance and Reactance
4: Impedance at the Transmitter, Feeder and Antenna
5: AIM4170 Functions
6: Measuring Capacitance, Inductance and Resonance
7: Typical Antenna Scans
8: Some other AIM4170 Functions
9: The Smith Chart
10: Time Division Reflectometry (TDR) Mode

18. Impedance (Z) and Reactance (X) of the Antenna System
Impedance (ohms) = Resistance (ohms) + j Reactance (ohms)
Z = R j X R
Radiation Resistance
DC Resistance X
“AC Resistance” due to Inductance/Capacitance
+ j

19. Vectors and “j”
Impedance (ohms) = Resistance (ohms) + j Reactance (ohms)
Z = R j X
= j 62
“j” means “rotate the vector by 90o”
Resistance (R)
30 ohms
Reactance (X) ohms

20. Inductive and Capacitive Reactance
Resistance (R)
30 ohms
Inductive Reactance (X) ohms
Resistance (R)
30 ohms
Capacitive Reactance (X) – 62 ohms
Z = 30 + j 62
Z = 30 – j 62

21. Inductive and Capacitive Reactance (X)XL
(ohms) L
XL = 2  f L
L = 1 µH f
(MHz) 1 10 1 10 C f
(MHz)
– 15.91
– 1
2  f C
XC =
– 159.1
C = 1 nF Xc
(ohms)

22. Vectors and Phase Angle (theta)
At 10MHz 30
+ 64 o
69.93 V I
+64 o
XL =
1 µH
R = 30
Z = 30 + j 62.84
Zmag = 69.63
XC = – 15.91 V 30
– 15.91
-28 o
33.96 I
1 nF
R = 30
Z = 30 – j 15.91
Zmag = 33.96
-28 o

23. Non-Resonant Antenna (at 5MHz)XL
(ohms) 5 f
(MHz)
– 31.82
L = 1 µH
C = 1 nF f
(MHz) Xc
(ohms) 5
At 5MHz V I
-0.7 o
XL =
XC = – 31.82 30
– 0.4
-0.7 o
1 µH
1 nF
R = 30
Z = 30 + j – j 31.82
= 30 – j 0.4

24. Resonant Antenna XL = – XC 1 2  f C 1 2  f C 2  f L 2  f L = = 1
At resonance, the inductive reactance and the capacitive reactance are equal
in magnitude and opposite in sign.
XL = – XC 1
2  f C 1
2  f C
2  f L
2  f L = = 1
2   (L C)
f res = 1
2   (1 µH * 1 nF)
f res =
= 5.033MHz

25. Resonant Antenna (at 5.033MHz)XL
(ohms)
5.033 f
(MHz)
– 31.62
L = 1 µH
C = 1 nF f
(MHz) Xc
(ohms)
5.033
At 5.033MHz V
XL =
XC = – 31.62 30 I
1 µH
1 nF
R = 30
0 o
Z = 30 + j – j 31.62
= 30 + j 0

26. AIM4170 Computations
1. Accurately measures the voltage, current and phase angle (theta)
2. Computes the resistance & reactance vectors, and the impedance
3. Computes the SWR, reflection coefficient, cable loss etc V I
+57 o 30
+57 o
55.70
Z = 30 + j 46.93
Zmag = 55.70
Z = V / I
SWR = Vmax
Vmin

27. AIM4170 Block Diagram
5kHz – 180MHz

28. AIM4170 PART 1 1: Introduction to the AIM4170
2: Some Basic Definitions
3: Impedance, Resistance and Reactance
4: Impedance at the Transmitter, Feeder and Antenna
5: AIM4170 Functions
6: Measuring Capacitance, Inductance and Resonance
7: Typical Antenna Scans
8: Some other AIM4170 Functions
9: The Smith Chart
10: Time Division Reflectometry (TDR) Mode

29. Impedance at the TX, Feeder and Antenna
The feeder is really an impedance transformer TX
Feeder
ATU
ZT = RT + jXT
= 50 + j0
ZF = RF + jXF
= 30 - j22
ZA = RA + jXA
= 16 + j123

30. AIM4170 Measurement Points
ANTENNA
SYSTEM
Feeder
AIM4170
ZF = RF + jXF
= 30 - j22
ZA = RA + jXA
= 16 + j123

31. AIM4170 PART 1 1: Introduction to the AIM4170
2: Some Basic Definitions
3: Impedance, Resistance and Reactance
4: Impedance at the Transmitter, Feeder and Antenna
5: AIM4170 Functions
6: Measuring Capacitance, Inductance and Resonance
7: Typical Antenna Scans
8: Some other AIM4170 Functions
9: The Smith Chart
10: Time Division Reflectometry (TDR) Mode

32. AIM4170 Functions - 1

33. AIM4170 Functions - 2

34. AIM4170 PART 1 1: Introduction to the AIM4170
2: Some Basic Definitions
3: Impedance, Resistance and Reactance
4: Impedance at the Transmitter, Feeder and Antenna
5: AIM4170 Functions
6: Measuring Capacitance, Inductance and Resonance
7: Typical Antenna Scans
8: Some other AIM4170 Functions
9: The Smith Chart
10: Time Division Reflectometry (TDR) Mode

35. AIM4170 Component Measurement

36. Measuring Capacitance

37. Measuring Inductance

38. Tuned Circuit Resonance

39. AIM4170 PART 1 1: Introduction to the AIM4170
2: Some Basic Definitions
3: Impedance, Resistance and Reactance
4: Impedance at the Transmitter, Feeder and Antenna
5: AIM4170 Functions
6: Measuring Capacitance, Inductance and Resonance
7: Typical Antenna Scans
8: Some other AIM4170 Functions
9: The Smith Chart
10: Time Division Reflectometry (TDR) Mode

40. 20m Dipole
(Courtesy Bob, W5BIG)

41. G5RV – 1-31MHz

42. G5RV on Top Band – coax feed

43. G5RV on Top Band – strapped feed (Marconi T)

44. 160m Inverted L at 140 feet
(Courtesy Paul, VE7BZ)

45. Hustler 5-BTV: 15m
(Courtesy Andy, M5ALA)

46. Hustler 5-BTV: 20m
(Courtesy Andy, M5ALA)

47. Hustler 5-BTV: 40m
(Courtesy Andy, M5ALA)

48. Hustler 5-BTV: 80m
(Courtesy Andy, M5ALA)

49. Antenna Loading
(Courtesy Steve, VK2ZSZ)

50. 2kW Dummy Load 1-151MHz

51. 2kW Dummy Load 1-151MHz

52. AIM4170 PART 1 1: Introduction to the AIM4170
2: Some Basic Definitions
3: Impedance, Resistance and Reactance
4: Impedance at the Transmitter, Feeder and Antenna
5: AIM4170 Functions
6: Measuring Capacitance, Inductance and Resonance
7: Typical Antenna Scans
8: Some other AIM4170 Functions
9: The Smith Chart
10: Time Division Reflectometry (TDR) Mode

53. Crystal Parameters

54. Short Circuit

55. Distance to Fault (short circuit)

56. Tuning a Quarter-Wave Stub

57. Band Scan

58. Frequency Markers

59. Marker Data

60. Spreadsheet

61. AIM4170 PART 1 1: Introduction to the AIM4170
2: Some Basic Definitions
3: Impedance, Resistance and Reactance
4: Impedance at the Transmitter, Feeder and Antenna
5: AIM4170 Functions
6: Measuring Capacitance, Inductance and Resonance
7: Typical Antenna Scans
8: Some other AIM4170 Functions
9: The Smith Chart
10: Time Division Reflectometry (TDR) Mode

62. Smith Chart

63. 50-ohm Termination: 1.5m Feeder

64. Smith Chart: Cable Attenuation – 1.5m Feeder
40MHz
80MHz
70MHz
0.68 – j0.53
x =
53 – j41

65. 50-ohm Termination: 32.5m Feeder

66. Smith Chart: Cable Attenuation – 32.5m Feeder

67. AIM4170 PART 1 1: Introduction to the AIM4170
2: Some Basic Definitions
3: Impedance, Resistance and Reactance
4: Impedance at the Transmitter, Feeder and Antenna
5: AIM4170 Functions
6: Measuring Capacitance, Inductance and Resonance
7: Typical Antenna Scans
8: Some other AIM4170 Functions
9: The Smith Chart
10: Time Division Reflectometry (TDR) Mode

68. Basic TDR

69. TDR Menu

70. 75-ohm feeder in series with 50-ohm feeder
Antenna
50-ohm
Feeder
75-ohm

71. Feeder with Low-Pass Filter inserted
Antenna
Feeder
50 MHz
Low-Pass Filter
without LPF
with LPF

72. AIM4170 ANTENNA ANALYZER End of Part 1
28 April 2011

73. This presentation is located at:
AIM4170
ANTENNA ANALYZER
Ian Wade, G3NRW
This presentation is located at:
homepage.ntlworld.com/wadei/aim4170.htm

74. AIM4170 ANTENNA ANALYZER Part 2
Ian Wade, G3NRW
8 September 2011
Copyright © 2010,2011 Ian Wade
All Rights Reserved

75. AIM4170 Antenna Analyzer
PART INTRODUCING THE ANALYZER
Antenna impedance – what does it mean?
AIM4170 capabilities
Examples
PART USING THE ANALYZER AS A DESIGN TOOL
Designing a 160m/80m Trap Dipole
Measuring the Antenna Feedpoint Impedance
Remote AIM4170 Operation

76. AIM4170 PART 2 11: Designing a 160m/80m Trap Dipole
12: The Feeder as an Impedance Transformer
13: Measuring the Antenna Feedpoint Impedance
14: Conjugate Matching
15: Remote AIM4170 Operation
16: Analyzer Comparisons
17: Conclusions

77. Live Demonstrations - 2 Determining antenna feedpoint impedance
Designing a 160m/80m trap dipole
Determining antenna feedpoint impedance
Conjugate matching in the ATU
Remote control of the AIM4170 via a WiFi link

78. AIM4170 PART 2 11: Designing a 160m/80m Trap Dipole
12: The Feeder as an Impedance Transformer
13: Measuring the Antenna Feedpoint Impedance
14: Conjugate Matching
15: Remote AIM4170 Operation
16: Analyzer Comparisons
17: Conclusions

79. Designing a 160m/80m Trap Dipole
At 80m
λ / 2 at 80m
Balun B
80mTrap
At 160m
λ / 2 at 160m A
Balun C B
Loading Coil

80. 80m Trap

81. 80m Trap: Resonant Freq = 3.6913MHz

82. From the Antenna Handbook:
The Dipole at 80m
At 80m
λ / 2 at 80m
Balun B
3.6913MHz
From the Antenna Handbook:
B = λ / 4 at 3.69MHz = 67 ft 6 inches (20.574m)

83. 80m Trap at 1.86MHz: Inductance = 9.18µH

84. The Dipole at 160m
At 160m
λ / 2 at 1.86MHz A
Balun
67’ 6”
9.18 µH

85. Calculating the Required Wire Lengths - 1
67’ 6”
9.18 µH
(Courtesy Martin, K7MEM)

86. Calculating the Required Wire Lengths - 2
67’ 6”
9.18 µH
(Courtesy Martin, K7MEM)

87. The Finished 160m/80m Trap Dipole Design
238’ 6”
80m trap
80m trap
Balun
51’ 9”
67’ 6”

88. Actual 160m/80m Dipole Results

89. AIM4170 PART 2 11: Designing a 160m/80m Trap Dipole
12: The Feeder as an Impedance Transformer
13: Measuring the Antenna Feedpoint Impedance
14: Conjugate Matching
15: Remote AIM4170 Operation
16: Analyzer Comparisons
17: Conclusions

90. Antenna System with Basic FeederTX
ATU

91. No resonance on 20m

92. Antenna System with Extra 1.5m of Feeder
Original
Feeder
Extra 1.5m of
Feeder TX
ATU

93. Extra 1.5m feeder: resonance on 20m

94. No resonance on 20m

95. Antenna System with Extra 3m of Feeder
Original
Feeder
Extra 3m of
Feeder TX
ATU

96. Extra 3m feeder: resonance (almost) on 30m

97. Extra 1.5m feeder: resonance on 20m

98. Original Feeder

99. The feeder is really an impedance transformer
AIM4170
ZF = 30 - j22
ZA = 16 + j123

100. AIM4170 PART 2 11: Designing a 160m/80m Trap Dipole
12: The Feeder as an Impedance Transformer
13: Measuring the Antenna Feedpoint Impedance
14: Conjugate Matching
15: Remote AIM4170 Operation
16: Analyzer Comparisons
17: Conclusions

101. One Way to Read the Antenna Feedpoint Impedance
AIM4170

102. Custom Scan
The AIM4170 reverses out the feeder impedance transformation to obtain
the antenna feedpoint impedance
Feeder
AIM4170
ZA = 16 + j123
ZF = 30 - j22
ZA = 16 + j123

103. Custom Feeder Calibration
AIM4170
1. Short Circuit
2. Open Circuit
3. Known Resistance
The custom calibration process is frequency dependent, so
it is necessary to produce a custom calibration file for each band.

104. Example: 50-ohm Resistive Load
Feeder
AIM4170
50 ohms
ZA = 50 + j0
ZF = 62+ j1
ZA = 50 + j0

105. 50-ohm Resistive Load: without correction
ZF = 62 + j 1

106. 50-ohm Resistive Load: with custom correction
ZA = j 0.1

107. 70MHz Groundplane: at feeder feedpoint
ZA = 43 + j 0

108. 70MHz Groundplane: at antenna feedpoint
ZA = 31 - j 23

109. AIM4170 PART 2 11: Designing a 160m/80m Trap Dipole
12: The Feeder as an Impedance Transformer
13: Measuring the Antenna Feedpoint Impedance
14: Conjugate Matching
15: Remote AIM4170 Operation
16: Analyzer Comparisons
17: Conclusions

110. The ATU has to convert the feeder feedpoint impedance to 50 + j0
Conjugate Matching
The ATU has to convert the feeder feedpoint impedance to 50 + j0 TX
Feeder
ATU
ZT = 50 + j0
ZF = 30 - j22

111. ATU Matching
(Courtesy Mike, WY2U)

112. AIM4170 PART 2 11: Designing a 160m/80m Trap Dipole
12: The Feeder as an Impedance Transformer
13: Measuring the Antenna Feedpoint Impedance
14: Conjugate Matching
15: Remote AIM4170 Operation
16: Analyzer Comparisons
17: Conclusions

113. AIM4170 Remote Control
AIM PC
AIM4170
AIM4170
AIM4170

114. AIM4170 Remote Control Remote AIM Netbook PC WiFi Connection AIM4170

115. Remote Desktop Control Server and Client
Remote netbook
running
Java-enabled
web browser
WiFi
AIM PC
running AIM software and
RealVNC remote desktop
control software
(any operating
system)
Wireless
Router
to antenna under test

116. Hazards of Remote AIM Control
Difficult to view display in bright light (need to increase screen brightness, increasing battery drain)
Risk of dropping the netbook (wear it on a halter around the neck)
Risk of overflying birds … (tape some cling film over the keyboard, or dress like a scarecrow and wave your arms about)

117. Remote Operation through Wireless RS-232 Link
WiFi RS-232 Link
VSC-X
to antenna under test

118. AIM4170 PART 2 11: Designing a 160m/80m Trap Dipole
12: The Feeder as an Impedance Transformer
13: Measuring the Antenna Feedpoint Impedance
14: Conjugate Matching
15: Remote AIM4170 Operation
16: Analyzer Comparisons
17: Conclusions

119. Analyzer Comparisons - 1
AIM4170
(Courtesy Bob, W5BIG)

120. Analyzer Comparisons - 2
AIM4170
£ 349
UK (Oct 2010)
£ 449

121. AIM4170 PART 2 11: Designing a 160m/80m Trap Dipole
12: The Feeder as an Impedance Transformer
13: Measuring the Antenna Feedpoint Impedance
14: Conjugate Matching
15: Remote AIM4170 Operation
16: Analyzer Comparisons
17: Conclusions

122. Conclusions The AIM4170: Accurate Software controlled Updateable
Easy to use
Remotely controllable
Detailed scan documentation

123. UK Supplier
Vine Antennas Ltd

124. Some Related Links AIM Software and Documentation:
Comparisons between AIM4170 and other analyzers:
Product Reviews, QST, August 2007
AIM Discussion Forum:
aim4150.proboards.com/index.cgi
RealVNC Remote Desktop Server:
Interactive Tutorials on Transmission Lines, SWR, Smith Chart:
Owen Duffy’s Experimenter’s Notebook:
vk1od.net

125. RadCom Review July 2007

126. Some Related Books www.arrl.org/shop/The-ARRL-Antenna-Book
Reflections III: by Walter Maxwell, W2DU w2du.com
Antenna Topics: by Pat Hawker, G3VA

127. Acknowledgements
Many thanks to the following who kindly gave permission for their work to
be included in this presentation:
AIM Software and Product Information, by Bob, W5BIG
160m Inverted L Plot, by Paul, VE7BZ
Hustler Antenna Plots, by Andy, M5ALA
Electrically Short Halfwave Dipole, by Martin, K7MEM
L/C Impedance Matching Network Design Tool, by Mike, WY2U
Analyzer Comparisons, by Bob, W5BIG

128. FINAL FINAL
W A R N I N G
The AIM4170 is
H U G E LY
addictive !

129. This presentation is located at:
AIM4170
ANTENNA ANALYZER
Ian Wade, G3NRW
This presentation is located at:
homepage.ntlworld.com/wadei/aim4170.htm