Dual band retractable antenna system with capacitive coupling

摘要

Dual band retractable antenna system with capacitive coupling comprises helical for operating at stand-by mode, the helical having 1/4 wavelength; whip, which penetrates the helical, for operating at busy mode, the whip having 1/4 wavelength; stopper for catching the whip when the antenna is extended out; sleeve mounted to one end of the helical, for operating as a feed point when the whip is extended out; capacitive coupling means placed between the helical and the sleeve, for capacitively coupling the helical to the sleeve; and matching circuit connected between the sleeve and the antenna system, so that the antenna system operates for both frequency bands.