The original Hentenna as a special kind of a single loop was described first in the 1970ies by Japanese Hams, an English article by JF6DEA/KE1EO about the Antenna ("The Hentenna – The Japanese 'Miracle' Wire")  was in the QST 1982 and in the ARRL-Antenna- Compendium, Vol. 5. The basic function of the  Hentenna structure is the 1,50-λ-Extended-Quad. This antenna with the figure of an "Oblong" has a gain of 3,6 dBd, but a feedpoint impedance of 73 + j 470 Ω.

The Hentenna has nearly the same gain, but a clever feeding with an impedance at XX of 50-70  +/- j 0 Ω .

The parts have the following lengths:

1, 6, 7: 0,15 λ

2, 4: 0,1 λ

3, 5: 0,5 λ

The data of the Hentenna-Loop:

Gain 3,05 dBd

3-dB-Azimuth-angle 88,2°, 3-dB-Elevation-angle 69,5°

The 144-MHz-Reflector- Hentenna by DK7ZB

With two reflector elements the Hentenna can be changed from a bidirectional antenna to an interesting directional antenna.

50-Ω-Impedance, fed with a 50-Ω-coax-choke (look for the pictures). A vertical metallic support through the antenna system has no influence to the feedpoint impedance and the resonant frequency!

Gain 7 dBd, F/B 15 dB

With two reflector elements the Hentenna can be changed from a bidirectional antenna to an interesting directional DX-antenna.

The data of the Hentenna with two reflectors by DK7ZB:

Gain 7,05 dBd, F/B 12,5 dB

Impedance 50 +/- j 0 Ω

3-dB-Azimuth-angle 71,4°, 3-dB-Elevation-angle 59°

The vertical pattern is a little bit asymmetric with a 3° upward lobe (see down).

Distance Ref-Loop 975 mm, all elements 12 mm diameter

The 50-MHz-Reflector-Hentenna

built by Luis, HI8LAM