Vertical ground-plane
Quarter-wave radiator and radial dimensions
Estimates the radiator length and radial span for a typical GP antenna at your target frequency, with suggested radial counts for different performance levels.
Formula:
Elevated radials cut close to 1/4λ minimise ground loss and set the correct current distribution. If you need to phase multiple sections or feed remote elements, the Quarter-wave Transformer shows how long each 1/4λ section should be in your chosen feedline.
A perfect quarter-wave radiator rarely sits at exactly 50Ω once mounted. If your analyser shows a mismatch, sketch a small L, Π or T network in the Matching Network Designer to tame reactance without sacrificing efficiency.