|LBA platform version 2.0. Photo: Markku Postila|
However, it seems that we will need to extend the ground plane with this type of a design. Recent antenna modeling results by Johan Borg of LTU suggests that this configuration has the effect of broadening of beam significantly at higher frequencies.
|NEC model of the antenna with a raised ground sheet.|
|40 MHz beam pattern of an individual element. Slight broadening at 40 MHz, but nothing too serious.|
|80 MHz beam pattern of an individual element. The raised platform causes a broadening of the beam and a deeper minima at the zenith.|