ANTENNA FOR RECEIVING CIRCULARLY POLARIZED WAVE

摘要

PROBLEM TO BE SOLVED: To provide an antenna for receiving circularly polarized waves which does not require a phase conversion circuit. SOLUTION: An antenna (10) for receiving circularly polarized waves has: a monopole antenna (12) having a pole part (122) and an earth plate (124) for grounding one terminal of the pole part; and a polarization conversion means (14) arranged around the monopole antenna. The polarization conversion means (14) is constituted of a plurality of helical conductors (141 to 144) which are spaced from the pole part (122) by a prescribed distance and are helically wound around the pole part (122) and have one ends grounded to the earth plate (124). The helical conductors (141 to 144) are arranged around the pole part at uniform angular intervals. The prescribed distance is 20 mm when a resonance wavelengthλis 128.3 mm. The length of each helical conductor isλ/4. A pitch angleθformed between the earth plate (124) and each of helical conductors (141 to 144) is 40°. COPYRIGHT: (C)2004,JPO