1. Family Tree of Antennas David Conn VE3KL
Acknowledgements
Doug Leach VE3XK
Bert Barry VE3QAA
QCWA Members
The Inventors
References given in slides
ARRL Antenna book
Doug for organizing the event and inviting me to make a presentation
Bert for the discussions about MF polarization
Many other QCWA members for their wisdom
The inventors of these antennas
W8ji and others referenced in my slides

2. Why Make a Family Tree To understand the overall (complex) picture
To enable us to select a good antenna
To organize and compare existing designs
Before going to the family tree, let’s look at the general types of antennas
To understand the overall (complex) picture, including the ionosphere, ground and simulators
To understand what type of antenna is important
To get a clear picture (in one web site) about all of the antenna issues
Antenna Types

3. Antenna Types 1…6
Resonant Wires: Dipole, Yagi, Quad, Vertical, Moxon Square …….
Long wires (non-resonant): Zepp/G5RV…
Resistively Loaded: Beverage, Pennant, Rhombic …
Small Loops/Wires: Resonant Loading Circuits
6 general types that overlap somewhat. 1 to 5 are quite different 6 is a special case and can be included in 1,3,4

4. Antenna Types 1…6
5. Phased Arrays: Yagi, Collinear, Sterba Curtain, Rhombic, Four Element Rectangular Array, Many Others …
Lens Antennas for UHF/Microwaves: Parabolic Dish, Helix …
Family Tree

5. Transmitting Antennas Simulation/Smith Chart
Radiation
Waves
Circuits
Transmission Lines
Ground/Ionosphere
Receiving Antennas
SNR
Transmitting Antennas
Power
Amateur Radio
Antennas
(index)
Simulation/Smith Chart
Microwave
A family tree modeled after hyperphysics (not really a tree because the subject is too complex).
Each ellipse represents an essential element and links to major designs/theory in the best web sites only. Each ellipse breaks down into a major study
There are less than 10 world class web sites. Can only look at a few instances
Radiation/Waves…..based on Maxwell’s Equations… E and H go together
Ground/Ionosphere dominate our signals
Transmission lines provide a low loss connection: A line might look line a transmission line but it isn’t.
Receiving antennas need to generate a high SNR.
Transmitting antennas need to launch energy in some desired direction
Modern simulators take us out of the days of “black magic”
Antennas grouped in bands from MF to microwave with lots of overlap
UHF/VHF MF HF

6. Transmitting Antennas
Performance measured by Gain & Directivity
Low Loss: Transmitter Matching
SWR of 2:1 loses half the power
Ground/Ionosphere… dominates
Polarization (Vertical for MF Transmitters)

7. Receiving Antennas…SNR
Performance measured by RDF (dB)
RDF (Receiving Directivity Factor) defined as peak response in desired direction to average response in all directions
Ground/Ionosphere… extremely important
Consider Polarization: VHF weak signal (DX) uses Horizontal Polarization
SNR counts…not gain. gain of a beverage -30 dB
Antenna Examples

8. MF Antennas Need good S/N…not Gain for Receive
Inverted L, T
Beverage Antenna… the best?
Terminated loops (Pennant, Flag)
Vertical Phased Arrays
Vertical GP antennas
K9AY Loop
4 Square Vertical
Green indicates Receive Only Antenna
Some for receive only

9. Inverted L,T,Vertical,K9AY Antennas
Very different antennas loop has very low gain

10. MF Receiving Antenna Performance
RDF, dB
Vertical phased array B/S 13
2 Broadside Beverages 1.75 W
Good
Beverage 1.0 W
8.64
Small 4X4 Square
Dipole
Flag/Pennant
Rdf vs cost
Above the dashed line is Good
Dipole….high cost or poor performance
Flag/pennant low cost (small) medium performance
Beverage: good cost/performance if 1.0 wavelengths long
Vertical OK
2 broadside Beverages good
Small 4X4 square good
Vertical phased array high cost ? Best RDF
K9AY
80 m high
Vertical Omni
Beverage 0.5 W
Bad
5.0
Cost
Low Dipole

11. Classic Dipole: type 1 .. Elevation Plot
35 feet
Ground
RDF = 8.3 dB Good

12. Classic Dipole: type 1 .. Azimuth Plot

13. Classic Vertical Ground Plane: type 1
RDF =5 dB
RDF worse in urban environments due to vertically polarized noise

14. Two Element Quad…Azimuth: type 1
RDF = dB…high
31 feet high to top
Similar performance to the yagi parasitic array very good RDF

15. End Fed Zepp Antenna: type 2
Example of a type 2 antenna
Antenna tuner needed
Radiation from the feed line
Television Interference
Not engineered
Noise?
Gain?
RDF?

16. MF Pennant…Receive only: type 3
Ground independent
Very Low Gain (-35 dB)
RDF = 7.39 dB…OK
Cardoid pattern
F/B 25 dB
Small..20 feet each arm
Terminated loop class
Low cost…medium/low performance/small

17. Small Magnetic Loop Antenna: type 4 Very High Voltages
g3ycc.karoo.net/loop.htm
High cost complex very narrow band high efficiency possible

18. Microwave Antenna Array: type 5 & 6 Space Diversity
Transmitter
Receivers
Wanted Rays
An array or two antennas with two receivers
Space diversity as an array or switched
Unwanted Rays
Arrays

19. Arrays
Driven arrays: Collinear, Sterba and Bobtail Curtains, two dimensional arrays, three dimensional (lens) arrays, Log Periodic
End fire or broadside or any beam shape
Parasitic arrays: Yagi

20. Linear Arrays (Driven) Directivity increases with Length

21. Four Element Rectangle.. Easy to Visualize
ARRL Antenna Book

22. Collinear Arrays

23. Bobtail Curtain Driven Array Maximum Gain 4.5 dBi Low Angle Radiation
ARRL Antenna Book

24. Dimensions repeat logarithmically QST Sept. 2002
Log Periodic Antenna Array…looks like a tapered Yagi but each element is driven
Very Broad Band
Dimensions repeat logarithmically
QST Sept. 2002
See one at crc
ARRL Antenna Book

25. VHF/UHF/Microwave Antennas
Yagi, Quagi, Quads ….stacked versions
Cycloid Dipole…
Circular Polarization..Repeaters
Helix and Helix Arrays
Vertical, Jpole
Corner Reflectors, Parabolas, Lenses
Circuit board patch antenna arrays
Many antennas from types 1, 5 and 6

26. The J Pole Antenna: type 1
Easy to Build
No ground plane needed
Many designs available
½ wave resonator with matching line
Multi band versions
Type 1 antenna

27. Cycloid Dipole Circular Polarization…Repeaters: type 1
Two elements to make Circular polarization
Circular polarization adds diversity fading margin for a transmit repeater

28. Summary
Tree must include antenna design as well as the physical description
Tree must include: ground effects, basics of the ionosphere
Tree must link to the most important well proven designs
Tree must help amateurs at all levels to select an appropriate antenna
Explain the four points
Thank Doug for making this presentation possible

29. Many Thanks: Especially to the Organizers