NEC-LIST: GPR antenna

Regarding Pascale's request for a wideband GPR antenna, I assume it is
important to have a frequency response which is easily compensated, to
enable the detection threshold to be set just above the noise. This
rules out dipoles, even resistively loaded ones. They are hard to
match over a wide frequency range, have too many peaks, and the
peak/trough frequencies are too sensitive to the environment. By the
time you put enough enough resistance in them to damp them out, you
might as well use a dummy load.

For this application it would be hard to beat a travelling wave
antenna. They are lossier than dipoles, and therefore require more
power, but at least their frequency response is easy to compensate.

Peter Nesbit VK3APN

pnesbit_at_melbpc.org.au
Received on Tue Apr 04 2000 - 04:01:16 EDT