LPs don't care!!

They are a driven array and fed from the shortest wavelength. So, as the
active region becomes resonant the RF Power is radiated by the active
region. The portion of the energy that 'sneaks by' the active region is
negligible.

Check the Tennadyne site: http://www.tennadyne.com and the ARRL
Antenna Handbook.


Actually Dave, it is a problem in some LPDA's:-). The self scaling of the
active region can degrade without a fix on some designs. Most commercial
LPDA's, such as the itty bitty WLAN LPDA's, have an inductive via as a short
to stop the back-resonance.

I'm sure they talk about this in one of the Antenna Compendiums. I can recall
the discussion but not the volume.


73,
Chip N1IR