"Little_skip" wrote in message
...

Hi everyone,

I would like some help with the HLP (Hybrid Log-Periodic) Antennas if
possible. I know nothing about antennas, yet I have a paper to write
about HLP Antennas (characteristics, calibration and so on) and I
didn't find anything about them. I found only datasheets for some of
the HLP antennas (mostly from TDK). Would it be a start to search about
log-periodic antennas and adapt the information? What would be the
difference between them?

Maybe it would sound like a stupid question to all of you, but I really
don't know where to start. Can someone give me a bit of help?

Thank you.
Little_skip

Hybrid Log-Periodic refers to a Log-Periodic Dipole Array antenna that uses
other types of elements in order to improve on some characteristic. One
example would be the typical TV antennas that have a UHF Yagi with Corner
Reflector using the same feed as the Log-Periodic elements. That example is
a hybrid of all three classic antenna configurations. If you were speaking
of the TDK models, you might have to look at one up-close to figure out what
technologies were involved (I have not) but it appears that it consists of a
classic Log-Periodic for VHF/UHF frequencies with additional elements for
the lower frequencies, such as linear loaded dipole or Quad elements. The
feed system is the key to hybrid multi-band and broadband antennas so that
the element configuration for one frequency is not compromised by the
inactive elements. With the TV antenna example, the LPDA and UHF Yagi are
essentially invisible to each other although they use the same feed and
boom.

Although this idea is attractive for frequency agile radios or for saving
the cost of feedline, performance is usually better for antennas optimized
for a limited range of frequencies.

It would be helpful for you to have knowledge of a variety of antenna
configurations, feed systems and technologies in order to do it justice.

You can write on anything at all. You just have to determine what you want
to convey.

I'm sure others will come out of the woodwork pretty soon.