Dual band ISM 2.4 GHz and 5 GHz finger antenna

In English A dual band antenna for two ISM bands at 2.4 GHz and 5 GHz has been evaluated. The antenna structure derives its advantage by deploying several radiators as fingers spreading from a single feeding point. Each radiator functions as both a half-wave and a quarter-wave radiator. Arranging them in parallel matches the half-wave resonance to 50 W. By carefully selecting the angle to ground plane and using mutual coupling, the quarter-wave resonance is also matched to 50 W. On average, the efficiency on the 2.4 GHz band is 71%, while on the 5 GHz band the efficiency is 75%. When placed close to a large shielding plane, performance is somewhat lowered, but still continues at a high level.