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

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

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

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

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

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)

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

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

Inverted L,T,Vertical,K9AY Antennas http://www.antennex.com/preview/archive3/ltv.htm http://www.aytechnologies.com/TechData/LoopInstall.htm Very different antennas loop has very low gain

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 http://www.w8ji.com/antennas.htm

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

Classic Dipole: type 1 .. Azimuth Plot

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

Two Element Quad…Azimuth: type 1 RDF = 12.84 dB…high 31 feet high to top Similar performance to the yagi parasitic array very good RDF

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?

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

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

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

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

Linear Arrays (Driven) Directivity increases with Length

Four Element Rectangle.. Easy to Visualize ARRL Antenna Book

Collinear Arrays http://www.tpub.com/neets/book10/42i.htm

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

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

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

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 http://www.cebik.com/jp2.html

Cycloid Dipole Circular Polarization…Repeaters: type 1 Two elements to make Circular polarization Circular polarization adds diversity fading margin for a transmit repeater http://www.wa7x.com/cycloid_info.html

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

Many Thanks: Especially to the Organizers http://www.dxlc.com/solar/