Antenna device and portable radio set

• US 6,362,793 B1
• Filed: 08/07/2000
• Issued: 03/26/2002
• Est. Priority Date: 08/06/1999
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kanayama, Yoshiki, Saito, Yuichiro, Sawamura, Masatoshi
• Primary Examiner(s): LE, HOANGANH T
• Application Number:
  US09/633,764
• Time in Patent Office: 596 Days
• Field of Search: H01/Q.124, H01/Q.136, 343/702, 343/895, 343/725, 343/729, 343/850, 343/853, 343/852, 343/859, 343/860, 343/865
• US Class Current: 343/702
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/244 extendable from a housing along a given path
• CPC Class Codes: H01Q 1/362 for broadside radiating helical antennas
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 9/30 with feed to end of elongated active element, e.g. unipole H01Q9/44 takes precedence
• CPC Class Codes: H04B 7/04 using two or more spaced independent antennas

Abstract

An antenna in which first and second antenna elements are selected by a switching apparatus so that the first and the second antenna elements are connected to an unbalanced transmission line via a balancing-unbalancing transmission line or only the first antenna element is connected to the unbalanced transmission line. The unbalanced transmission line supplies power via a balanced-to-unbalanced transformation apparatus to the first and the second antenna elements, so as to operate as an antenna, at which time, balanced-to-unbalanced transformation action of the balanced-to-unbalanced transformation apparatus prevents leakage current from flowing from the first or the second antenna element to the unbalanced transmission line and prevents a ground element on which the unbalanced transmission line is grounded from operating as an antenna. This reduces deterioration of antenna characteristics in the vicinity of a human body, so that an antenna device and portable radio set which can sizably reduce deterioration of communication quality can be realized.

Claims

1. An antenna device of a diversity reception system, comprising:

a first antenna element installed so as to be retracted and pulled out freely;

a fixed second antenna element;

an unbalanced transmission line for supplying said first and second antenna elements with power;

balancing-unbalancing transformation means for implementing balancing-unbalancing transformation action between said unbalanced transmission line and said first and second antenna elements; and

switching means for selectively switching connections of said unbalanced transmission line with said first and second antenna elements and with only said first antenna element so that, at the time of reception, said first and second antenna elements are brought into connection with said unbalanced transmission line via said balancing-unbalancing transformation means, or only said second antenna element is brought into connection with said unbalanced transmission line,

wherein said switching means are arranged to bring said unbalanced transmission line into connection with said the first and second antenna elements via said balancing-unbalancing transformation means so that said unbalanced transmission line supplies said first and second antenna elements with power via said balancing-unbalancing transformation means so as to operate said first and second antenna elements as an antenna.

2. The antenna device according to claim 1, wherein

said switching means causes said first and second antenna elements to operate as an antenna at the time of transmission, when said unbalanced transmission line is brought into connection with said first and second antenna elements via said balancing-unbalancing transformation means so that said unbalanced transmission line supplies said first and second antenna elements with power.

3. The antenna device according to claim 2, wherein

said first antenna element has a stick form rod antenna provided so as to be retracted and pulled out freely, and

said second antenna element is configured by a spiral-formed fixed helical antenna to be disposed so that a central axis of a spiral is made approximately perpendicular to an elongated direction of said rod antenna.

4. The antenna device according to claim 2, wherein

said first antenna element has a stick form rod antenna provided so as to be retracted and pulled out freely, and

said second antenna element is configured by a spiral-formed fixed helical antenna to be disposed so that said rod antenna is thrust and pulled out along a central axis of a spiral of said helical antenna.

5. The antenna device according to claim 2, wherein

said first antenna element has a stick form rod antenna provided so as to be retracted and pulled out freely, and

said second antenna element is configured by a spiral-formed fixed helical antenna to be disposed so that a central axis of said rod antenna is to be approximately perpendicular to an elongated direction of said rod antenna.

6. The antenna device according to claim 2, wherein

said first antenna element comprises a stick form rod antenna provided so as to be retracted and pulled out freely, and

said second antenna element comprises a first spiral-formed fixed helical antenna, and further comprising

a second spiral-formed fixed second helical antenna, wherein at least one end of said second helical antenna is brought into electrical connection with said rod antenna so that a compound antenna is formed when said rod antenna is retracted or pulled out.

7. The antenna device according to claim 6, wherein

said second helical antenna is disposed so that said rod antenna is thrust or pulled out along a central axis of a spiral of said helical antenna.

8. The antenna device according to claim 6, wherein

said second helical antenna is disposed so that a central axis of a spiral of said helical antenna is approximately parallel to an elongated direction of said rod antenna.

9. The antenna device according to claim 6, wherein

said rod antenna is formed of elastic material so as to comprise a conductive cylindrical member having a cavity through which a conductive stick form member is inserted.

10. A portable radio set having an antenna device of a diversity reception system, wherein said antenna device comprises:

a first antenna element installed so as to be retracted and pulled out freely;

a fixed second antenna element;

an unbalanced transmission line for supplying said first and second antenna elements with power;

balancing-unbalancing transformation means for implementing balancing-unbalancing transformation action between said unbalanced transmission line and said first and second antenna elements;

switching means for selectively switching connections of said unbalanced transmission line with said first and second antenna elements and with only said first antenna element so that, at the time of reception, said first and second antenna elements are brought into connection with said unbalanced transmission line via said balancing-unbalancing transformation means, or only said second antenna element is brought into connection with said unbalanced transmission line; and

said switching means are arranged to bring said unbalanced transmission line into connection with said the first and second antenna elements via said balancing-unbalancing transformation means so that said unbalanced transmission line supplies said first and second antenna elements with power via said balancing-unbalancing transformation means so as to operate said first and second antenna elements as an antenna.

11. The portable radio set according to claim 10, wherein

in said antenna device, said switching means cause said first and second antenna elements to operate as an antenna at a time of transmission, when said unbalanced transmission line is brought into connection with said first and second antenna elements via said balanced-unbalanced transmission line by means of said switching means so that said unbalanced transmission line supplies said first and second antenna elements with power via said balancing-unbalancing transformation means.

12. The portable radio set according to claim 11, wherein

said first antenna element comprises a stick form rod antenna provided so as to be retracted and pulled out freely, and

said second antenna element is configured by a spiral-formed fixed helical antenna, and is disposed so that a central axis of a spiral of said helical antenna is approximately parallel to an elongated direction of said rod antenna.

13. The portable radio set according to claim 11, wherein

said first antenna element comprises a stick form rod antenna provided so as to be retracted and pulled out freely, and

said second antenna element is configured by a spiral-formed fixed helical antenna, and is disposed so that said rod antenna is thrust or pulled out along a central axis of a spiral of said helical antenna.

14. The portable radio set according to claim 11, wherein

said first antenna element comprises a stick form rod antenna provided so as to be retracted and pulled out freely, and

said second antenna element is configured by a spiral-formed fixed helical antenna, and is disposed so that a central axis of a spiral of said helical antenna is approximately parallel to an elongated direction of said rod antenna.

15. The portable radio set according to claim 11, wherein

said first antenna element comprises a stick form rod antenna provided so as to be retracted and pulled out freely, and

said second antenna element comprises a first spiral-formed fixed helical antenna, and further comprising

a second spiral-formed fixed second helical antenna, wherein at least one end of said second helical antenna is brought into electrical connection with said rod antenna so that a compound antenna is formed at a time when said rod antenna is retracted or pulled out.

16. The portable radio set according to claim 15, wherein

said second helical antenna is disposed so that said rod antenna is thrust or pulled out along a central axis of a spiral of said helical antenna.

17. The portable radio set according to claim 15, wherein

said second helical antenna is disposed so that said central axis of a spiral of said helical antenna is approximately parallel to an elongated direction of said rod antenna.

18. The portable radio set according to claim 15, wherein

said rod antenna is formed of elastic material so as to comprise a conductive cylindrical member having a cavity through which a conductive stick form member is inserted.