NEC-LIST: GPR antennas

I am working on an impulse GPR (Ground Penetrating Radar) project in
the 5-50MHz band. My goal is to model and consequently fabricate an
antenna in this band of frequencies.

In GPR we generally use resistive dipoles, but the problem with this
type of antennas is that their length is of the order of the
half-wavelength. So for low frequencies, the antennas are very
long.... For example an antenna with a central frequency of 8 MHz on
the ground with a relative dielectric constant of 3.5 is as much as
12.5 m long!

I would like to know if there will be any suggestions on how these
antenna lengths can be reduced or rather if any more convinient
antenna can be prescribed for me.

Thanks for the attention.

Best regards.

Lutz Pascale.

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| Pascale LUTZ | e-mail : pascale.lutz_at_univ-pau.fr |
| Laboratoire d'Imagerie Geophysique | |
| Universite de Pau | Tel: 33 (0)5 59 92 31 74 |
| et des Pays de l'Adour | Fax: 33 (0)5 59 92 31 86 |
| Avenue de l'Universite | |
| 64000 Pau | |
| France | |
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Received on Wed Mar 29 2000 - 20:52:37 EST