Patent Number: 6,396,442

Title: Circularly polarized antenna device and radio communication apparatus using the same

Abstract: A circularly polarized antenna device in which a recess is formed in the bottom surface of a dielectric base, and in which a feeder circuit is formed on an area of the top surface of a feeder circuit board covered by the recess. A shield for the feeder circuit is provided inside the recess. A feeder electrode is formed on an outer peripheral side surface of the dielectric base so as to be separated from a radiation electrode. A feeder wiring pattern which connects the feeder circuit and the feeder electrode so that they are in electrical conduction is formed on the top surface of the feeder circuit board. Electrical power supplied to the feeder electrode from the feeder circuit through the feeder wiring pattern is transmitted to the radiation electrode by capacitive coupling. Since the feeder circuit and the shield are accommodated inside the recess of the dielectric base, it is possible to restrict the bulkiness of the circularly polarized antenna device, and, thus, to make it thin. The invention aims at making the circularly polarized antenna device thinner.

Inventors: Kawahata; Kazunari (Machida, JP), Ito; Shigekazu (Sagamihara, JP), Yuasa; Atsuyuki (Sagamihara, JP), Akiyama; Hisashi (Yokohama, JP)

Assignee: Murata Manufacturing Co., Ltd.

International Classification: H01Q 9/04 (20060101); H01Q 001/38 ()

Expiration Date: 05/28/2019