portable-antennas - dipoles-beam antenna

Use the controls on the left-hand side to configure your antenna - set the design frequency, antenna element lengths and angles, wire diameter, wire insulation if required, support height, etc.
When you are happy with your configuration, press the "Show antenna" button to display your antenna in interactive 3D graphics mode in the area on the right-hand side. Each time you change your configuration, you should press the "Show antenna" button to register the changes to the app.
After you have configured your antenna, you can then use the controls further down in the page to generate charts and diagrams to evaluate the antenna's performance - you will need to scroll down in the page to access these controls.
You can choose to view any combination of the available charts and diagrams: these include four radiation pattern types: azimuth, elevation, 3D and polarization patterns; other options include VSWR charts, an antenna currents diagram, and a Smith chart.

Show person-height plane

Antenna sections
No. of bands:
Section #1:	kHz ( highest f )
Section #2:	kHz
Section #3:	kHz
Section #4:	kHz
Section #5:	kHz
Section #6:	kHz ( lowest f )
Antenna wire
Wire core:	mm diameter
Material:
Insulation:	thickness
Ins. type:	Corr. factor:
Antenna configuration
Pole height:	m
Apex angle:	°
Slope length:	m
Rope extender:	m
Foot length:	m
Side length:	m
Director capacitance multiplication factor
Mult. factor:	=> Capacitance: pF

Antenna overview

Antenna sections

Inner
#1

Freq. (kHz)

Length (m)

Total (m)

½ Length:

½ Apex∠:

End height:

Dipoles-beam antenna designer

Use the controls on the left-hand side to configure your antenna.
When you are happy with your configuration, press the "Show antenna" button to display your antenna in interactive 3D graphics mode in this area.
After you have configured your antenna, you can then use the controls further down in the page to generate charts and diagrams to evaluate the antenna's performance ...

portable-antennas.com

Antenna feed-point: ⬥ Arrow shows direction of main beam

Show display hints:

Effect of coax- and system-losses on VSWR

When a coaxial cable is used to connect the antenna to a transmitter, the cable introduces signal loss, the magnitude of which can vary strongly with both frequency and antenna feed-point impedance.

The main blue VSWR curve for this antenna is calculated at the antenna feed-point. The optional green curve represents the VSWR "seen" at the transmitter after losses in the coaxial cable are taken into account.

At frequencies of antenna resonance, the blue and green curves usually coincide closely, since the coax contributes little additional attenuation at those frequencies. At frequencies away from resonance, however — often those corresponding to WARC bands — the feed-point impedance may become highly mismatched, producing very high VSWR values in the blue curve while the green curve shows substantially lower values.

This reduction in VSWR at the transmitter occurs because signal losses in the coaxial cable attenuate both the forward and reflected waves. As a result, the reflected signal returning to the transmitter is weaker, causing the transmitter-end VSWR to appear lower than the actual feed-point VSWR.

This effect can make some bands appear more "usable" from the transmitter's perspective, even though the antenna system may still be operating inefficiently at those frequencies.

The green curve represents the "flattening" of the VSWR caused by the coax. Additional losses elsewhere in the system can further reduce the transmitter-end VSWR - these may include:

ferrite heating and winding losses in baluns/ununs
common-mode currents suppression
coupling of RF energy into nearby ground and objects
matching network / antenna tuner losses

The magnitude of such losses, and their effect on actual radiated RF power, can only be estimated reliably through careful analysis of a particular antenna setup. In every-day portable operations, such losses can only be roughly estimated; however, comparisons can be made between commercially-produced EFHW and OCFD antennas for amateur radio use, and carefully-configured NEC models of those same antennas. Useful estimates can then be made of the efficiency of the commercial products by comparing their published VSWR curves, and the VSWR curves produced from the models.

Improved transmitter-end VSWR therefore does not necessarily imply improved radiation efficiency: in some cases, a significant proportion of the transmitted power may simply be lost: dissipated as heat within the antenna system. Read more...

Antenna: Configuration: Frequency: GenID:

Antenna
plane
0° - 180°

Azimuth:
Gain:
Beamwidth:	N/A
(At elevation angle: 133°)

Elevation:
Gain:
Beamwidth:	N/A
(At azimuth angle: 133°)

General parameters (at 7.000 MHz)

Outer ring:	5.23 dBi
VSWR:	2.06 : 1
Unun ratio:	49 : 1
Feed-point Z:	5125 - j1983 Ω
Transformed Z:	xxx

Show selected azimuth/elevation slices in 3D plot

How to use these diagrams » » »

Set frequencies by band

Choose bands
(highest freq. first) :

Section #1 ( highest f )	Section #2	Section #3	Section #4	Section #5	Section #6

Bands portion:

CW Mid-band SSB

"4DX" Dipoles beam antenna designer - Reference

Loading capacitor value vs. frequency

The capacitances given here are approximate values, based on results derived empirically by VK6VZ and VK6LW, to give optimal gain figures in the field. You can use the "Capacitance multiplication factor" control in the designer to adjust the value used in your own antenna configuration.

Coordinates of one section of this antenna can be used to model a single antenna
with the same apex ½-angle in a separate program

#	Freq. MHz	Section Length	Total Length	Wire segment			Full element coordinates
#	Freq. MHz	Section Length	Total Length	Δx	Δy	Δz	x1	y1	z1	x2	y2	z2
1	1	1	1	1	1	1	1	1	1

Copy this CSV text and paste into your favorite spreadsheet program

Export antenna dimensions to file

Export format:
Antenna diagram:	Use original view Use current view
PDF options: Toggle all	Include radiation patterns Include VSWR chart Include currents diagram Include Smith chart If you include any of these options, make sure you refresh the required radiation patterns, charts and diagrams for your antenna before exporting.
Collecting data:	0 %

Combined azimuth + elevation patterns

Using combined azimuth + elevation patterns

The new combined azimuth and elevation patterns diagrams are fully interactive, allowing dynamic re-plotting of the patterns. You can choose any one of the following levels of interactivity:

No interaction
- the diagrams remain fixed at their default azimuth and elevation cuts.
Hover the mouse over the circular region in one diagram
- a green radial line and marker pair will appear in the diagram;
- the line and marker will follow the mouse around the diagram;
- angle and gain values at the mouse position are updated in the texts directly below the diagram.
Click within the circular region in one diagram
- the radial axis (the black line with numbers) is re-positioned to the selected angle;
- this new radial-axis position defines a new "slice" through the 3D radiation-patterns data;
- the other diagram is then re-plotted to reflect the new slice through the data;
- if the 3D radiation-pattern diagram is visible, then it too will be re-plotted to reflect the new slice through the data.
Click and drag within the circular region in one diagram
- the radial axis follows the mouse position in that diagram continuously;
- releasing the mouse fixes the radial axis at the selected angle;
- a new slice through the 3D radiation-patterns data is generated;
- the other diagram is then re-plotted to reflect the new slice through the data.
- if the 3D radiation-pattern diagram is visible, then it too will be re-plotted to reflect the new slice through the data.

All these different levels of interactivity are not just for show - they are designed to engage your curiosity about azimuth, elevation and 3D patterns and curves, and to help you learn about them.

By using the different levels of interactivity, you should gain a deeper insight into how each of the patterns and curves are intimately connected. Change one, and the other two are affected.

How deeply you venture into this, is entirely up to you: the tools are provided for you to use.

Choose antenna section:	#1
Check harmonics?:	No Third Fifth kHz
Choose ground type of land in the vicinity of the antenna:	Conductivity: S/m Dielectric const.: F/m
View radiation patterns:	Azimuth + Elevation Polarization patterns
	3D pattern Choose type: Classic 3D plot
Set ref. elevation angle:	Auto Choose:
Set ref. azimuth angle:	Auto 0° (inline) 90° (broadside)
View VSWR chart:	VSWR chart
Effect of coax on VSWR: Coax losses info » » »	Include coax losses Coax length: Type: Effect of coax- and system-losses on VSWR When a coaxial cable is used to connect the antenna to a transmitter, the cable introduces signal loss, the magnitude of which can vary strongly with both frequency and antenna feed-point impedance. The main blue VSWR curve for this antenna is calculated at the antenna feed-point. The optional green curve represents the VSWR "seen" at the transmitter after losses in the coaxial cable are taken into account. At frequencies of antenna resonance, the blue and green curves usually coincide closely, since the coax contributes little additional attenuation at those frequencies. At frequencies away from resonance, however — often those corresponding to WARC bands — the feed-point impedance may become highly mismatched, producing very high VSWR values in the blue curve while the green curve shows substantially lower values. This reduction in VSWR at the transmitter occurs because signal losses in the coaxial cable attenuate both the forward and reflected waves. As a result, the reflected signal returning to the transmitter is weaker, causing the transmitter-end VSWR to appear lower than the actual feed-point VSWR. This effect can make some bands appear more "usable" from the transmitter's perspective, even though the antenna system may still be operating inefficiently at those frequencies. The green curve represents the "flattening" of the VSWR caused by the coax. Additional losses elsewhere in the system can further reduce the transmitter-end VSWR - these may include: ferrite heating and winding losses in baluns/ununs common-mode currents suppression coupling of RF energy into nearby ground and objects matching network / antenna tuner losses The magnitude of such losses, and their effect on actual radiated RF power, can only be estimated reliably through careful analysis of a particular antenna setup. In every-day portable operations, such losses can only be roughly estimated; however, comparisons can be made between commercially-produced EFHW and OCFD antennas for amateur radio use, and carefully-configured NEC models of those same antennas. Useful estimates can then be made of the efficiency of the commercial products by comparing their published VSWR curves, and the VSWR curves produced from the models. Improved transmitter-end VSWR therefore does not necessarily imply improved radiation efficiency: in some cases, a significant proportion of the transmitted power may simply be lost: dissipated as heat within the antenna system. Read more...
View currents diagram	Antenna currents diagram
View Smith chart:	Smith chart
Antenna gains at 0° elevation:
Feed-point impedance:
Estimated bandwidth:

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Specials - "4DX" Dipoles-beam antenna

Antenna performance

Effect of coax- and system-losses on VSWR

Loading capacitor value vs. frequency

Using combined azimuth + elevation patterns