| 摘要 |
PROBLEM TO BE SOLVED: To provide a compact and highly sensitive shared antenna which is suitable to both satellite communication and terrestrial communication by properly placing a microstrip line planar antenna and a helical antenna. SOLUTION: A helical antenna 9 is obtained by winding a conductor 8 around a dielectric cylinder 7 with a fixed pitch. A coaxial wire 13 is led through the center axis of the cylinder of the antenna 9 to feed a microstrip line planar antenna 6 of a back-to-back feed system. Then the antenna 6 is placed above the antenna 9. A feed pin 1 of the antenna 6 receives the power via a center conductor 12 of the wire 13, and the power is supplied to the antenna 9 via the lower edge of the antenna 9 and a ground plate 4. A portable telephone set is provided with a switch to select either antennas 6 and 9 and operates separately between the frequency f1 and f2. In other words, the satellite communication is performed with a satellite by the circularly polarized wave through the antenna 6 and the terrestrial communication is performed with a ground base station by the linearly polarized wave through the antenna 9 respectively. |
