Antenna device for direction finders

An antenna device for a direction finder, comprising:

• (a) a substantially grounded conductive base plate including a conductive plate mounted on said base plate;
• (b) a plurality of web-shaped antenna elements mounted in spaced relation on said base plate and having central portions extending in crisscross relation and insulated from each other said web-shaped antenna elements having widths progressively increased toward their ends and spaced from said conductive plate by a distance progressively increased toward said ends of the antenna elements so that said antenna elements have substantially uniform characteristic impedances, said antenna elements being grounded through resistors having resistances substantially equal to the characteristic impedances thereof;
• (c) an electronic switching circuit for alternately grounding ends of said antenna elements and picking up reception outputs from opposite ends of said antenna elements at a constant period with said antenna elements being switched out of phase at an angle corresponding to the angle at which said antenna elements extend across each other;
• and
• (d) a circuit for combining outputs from said antenna elements.