Design a directional wire beam antenna for one or more bands, consisting of an array of two angled inverted-vee dipoles, the apexes of which are arranged very close to each other at the center. Each half of the array is a full-sized dipole antenna: to achieve directionality, one of the dipoles is loaded capacitively at the apex, effectively shortening its' legs electrically. This dipole then becomes a "director" for the other, "driver", dipole, and the array radiates preferentially in that direction. Some operators have arranged switchable capacitors and feed-point positions on each pair of arms of the array, such that the array can be quickly arranged to radiate in any one of four different directions. Gains of 9dBi or greater can be achieved, and F/B ratios of 12dB or greater are possible, depending on height, apex-angle and frequency.
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Dipoles-beam antenna designer
Antenna feed-point: ⬥
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Here you can generate plots of radiation patterns, VSWR chart, antenna currents diagram and Smith chart for your antenna over a
choice of ground types. By changing the physical dimensions of the antenna, and refreshing these plots, you can learn a lot about
how such antennas will perform in the field.
Please note that
radiation patterns are here modelled over flat ground -
when the antenna is erected on a hill-top or mountain summit, the surrounding sloping ground will generally cause angles in
the elevation radiation pattern to be lowered in the direction of the
slope: the steeper the slope, the lower the effective elevation take-off angle will be, and the better the chances of making
long-distance contacts.
Choose antenna section: | |
Check harmonics?: | kHz |
Choose ground type of
land in the vicinity of the antenna: |
Conductivity:
S/m
Dielectric const.:
F/m
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View radiation patterns: |
Set elevation angle for azimuth plot:
Set azimuth angle for elevation plot: |
Chart patterns for: at spacing | |
View VSWR chart: | |
Impedance curves scales: | |
View currents diagram | |
View Smith chart: | |
Antenna gains at 0° elevation: |
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Antenna impedance: | |
Frequency range: | |