[TowerTalk] Front-to-back / Front-to-rear

[Scott McClements]

Hi,

Since I am in the process of designing a new directional antenna
(w/NEC2), I have started to think about which measure(s) of rearward
rejection I would maximize on:

1. Front-to-back - Difference in gain in main lobe direction and 180
degrees opposite
2. Worst case front-to-back - Difference in gain between main lobe and
highest gain in the quadrants opposite the main lobe.
3. Front-to-rear - Difference in gain between main lobe and average gain
in the two quadrants opposite the main lobe.

I can easily understand the pros (and cons) of high front-to-back.
But I am trying to understand which is more desirable for a
directional antenna that will be used on 14Mhz-30Mhz -  a high worst
case F/B or high F/R.  What would be the practical difference between
the two?

In calculating F/R, to maximize performance,  would it make more sense
to average gain over a smaller range, say +/- 45 degrees opposite the
main lobe (instead of +/- 90 degrees)?

-Scott, WU2X