Vladimir Polyakov, RA3AAE,
HF- magazine, 1998, pp.: 27- 31
in Russian in Moscow).
I would like
to make a simple directional
I had observed lots
stopped at ZL- beam with two
active feeding. The
very attractive for me.
This one at
its small sizes (only
in length) was
the same parameters as 3-
1 shows a simple design of the ZL- beam. Points X-X
is the feeding terminal of the antenna. ZL- beam consists of two
dipoles (simple or folded) that connected together by crossed
wires. Depending on the length of the fires the dipoles fed by
some phase shift that helps form the diagram of directivity. (Note by I.G.:
More about ZL-Beam see References 1 and 2)
shift between the
are obtained by two
ways. At first,
it needs change the length
of the crossed
line. The second, (it is
by changing of the length of
If the tuning may be made
then no matter
at which points at the
would be connected feeder
of the antenna.
Usually ZL-beam is used as antenna with horizontal
polarization i.e. the dipoles are placed in parallel to ground.
That is because of the simplicity of that antenna design.
I decided to make antenna with vertical placement of
the dipoles to ground. For the antenna’s
element should be suitable J- Antenna. (Note by I.G.: More
about J- Antenna see References
3 and 4). Figure 2 shows two version of that J- Antenna.
Version of the antenna with the grounded stub (right at the Figure 2)
is mostly suitable for my design. It is possible to connect the lower point of the grounded stub with
any ground- roof of the car, metal mast and so on. It is possible
to match the antenna with any coaxial cable by choosing the feeding