Compact 6-element antenna of Yagi of the range of 144 MHz

October

2020

Compact 6-element antenna of Yagi of the range of 144 MHz

антенны

22 October 2020 13:08

Most 6 -element antennas per range of 144 MHz suffer in one drawback - the length of their traverse is more than 2 meters.
But the square profile and pipes in the store have a length of 2 meters smoothly.
I calculated the compact (1.96m length) antenna for the range of 144-146 MHz, 1 meter 94 centimeters long, without the need to drink or increase the traverse.

The wavelength of the range is 144 MHz-2.2 meters, on the traverse the antenna of the Uda-Yagi manages to place only 5 elements.
The 5-element antenna has an increase of not higher than 10 dBi and the weak suppression of the side petals of the orientation diagram.

Taking into account the specified conditions, it was possible to calculate the antenna of 6 elements with good parameters:

Strengthening in free space - 10.92 dBi (8.77 dBd).
Signal suppression from a direction of 180 degrees - 25 dB
Signal suppression on the side of 6 dB.
Range of good matching with a cable 50 Ohms - 144 ... 148 MHz (at SWR < 1.5)
Dimensions 1.94 x 1.03 meters.

With the help of deep minimums, the orientation diagram will be able to rebuild from interference.

Antenna material - aluminum tubes with a diameter of 8 mm (sold in construction stores).
The antenna can be placed both in the vertical and horizontal plane.

Field diagram when installed for vertical polarization:

Field diagram when installed for horizontal polarization:

Coordination with a cable 50 Ohms (SCS) and SWR, broadband (working frequency) Antenna:

Sizes of elements:

Element	Position, mm	Length, mm
Reflector	0	1026
Vibrator	309	1017
Director 1	402	951
Director 2	779	924
Director 3	1360	893
Director 4	1940	811

Boom Correction

Boom-correction, i.e. Changing the length of the elements to compensate for the effect on the parameters of the antenna of the metal traverse ("boom") this antenna is not needed. Since when placing the antenna elements on a metal boom, when they are shortened by a significant disorder, the antenna does not occur: SWR and strengthening remain the same as on the dielectric boom.

Settings

The displacement of the active element to the first director increases active resistance.
The displacement of the active element to the reflector reduces the input resistance.
Moving the first director to the active element lowers the resonance frequency.
Moving the first director to the second director increases the frequency of resonance.
Moving the last director to the far end of the traverse increases the resonance frequency.

Model for MMANA software
144-6el-8mm-ra1ahq.maa.zip