Antenna and radio device comprising the same

• US 6,661,391 B2
• Filed: 05/01/2002
• Issued: 12/09/2003
• Est. Priority Date: 06/09/2000
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Ohara, Masahiro, Fukumura, Toyoshi
• Primary Examiner(s): Ho, Tan
• Application Number:
  US10/048,062
• Publication Number:
  US 20020149537A1
• Time in Patent Office: 587 Days
• Field of Search: 343/895, 343/872, 343/702, 343/853, 296/00
• US Class Current: 343/895
• CPC Class Codes: H01Q 1/242 specially adapted for hand-held use
• CPC Class Codes: H01Q 1/36 Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewithH01Q1/08, H01Q1/14 take precedence
• CPC Class Codes: H01Q 1/362 for broadside radiating helical antennas
• CPC Class Codes: H01Q 1/40 Radiating elements coated with or embedded in protective material
• CPC Class Codes: H01Q 5/00 Arrangements for simultaneous operation of antennas on two or more different wavebands, e.g. dual-band or multi-band arrangements combinations of separate active antenna units operating in different wavebands and connected to a common feeder system H01Q21/30
• CPC Class Codes: H01Q 5/357 using a single feed point

Abstract

An antenna is capable of transmitting/receiving waves in multi-ranged frequency bands, and providing high antenna gain, reliability and productivity. A radio communication apparatus uses the antenna. A feed portion is electrically connected with an antenna element portion at one end, and with radio-frequency circuitry of the apparatus at another end. A dielectric material core rod mechanically supports the antenna element portion. A dielectric material radome partially covers the antenna element and feed portion. The antenna element portion is formed from an approximately helical-shaped portion and an approximately meander-shaped portion, both of which are made from a thin-belt-shaped conductive plate and concentrically arranged on the core rod. Properly adjusting of the approximately helical-shaped and the approximately meander-shaped portions can provide impedance characteristics optimal for multi-ranged frequency bands.

Claims

1. An antenna for transmitting/receiving waves in a plurality of frequency bands, comprising:

a conductive antenna element portion;

a feed portion for establishing electrical connections between said conductive antenna element portion and a radio-frequency circuit of a radio communication apparatus; and

a dielectric core rod mechanically supporting said conductive antenna element portion,

wherein said conductive antenna element portion includes

(i) an approximately helical-shaped portion concentric with said dielectric core rod, said approximately helical-shaped portion comprising

(a) half round and thin belt-shaped first conductors having a diameter that is generally equal to a diameter of said dielectric core rod, said half-round and thin belt-shaped first conductors being arranged, in an axial direction of said dielectric core rod from near an end of said dielectric core rod, on a front round surface and a rear round surface of said dielectric core rod, said half-round and thin belt-shaped first conductors on said front round surface being spaced from one another along the axial direction of said core rod by a predetermined interval and said half-round and thin belt-shaped first conductors on said rear round surface being spaced from one another along the axial direction of said core rod by a predetermined interval, and said half-round and thin belt-shaped first conductors being parallel with one another, such that along the axial direction of said core rod said half-round and thin belt-shaped first conductors on said front round surface are staggered relative to said half-round and thin belt-shaped first conductors on said rear round surface, and

(b) short and thin belt-shaped conductors interconnecting free ends of said half-round and thin belt-shaped first conductors on said front round surface with adjacent free ends of said half-round and thin belt-shaped first conductors on said rear round surface, respectively, and

(ii) an approximately meander-shaped portion adjacent said approximately helical-shaped portion, said approximately meander-shaped portion comprising

(a) parallel thin belt-shaped second conductors, and

(b) short thin belt-shaped conductors interconnecting adjacent free ends of said parallel thin belt-shaped second conductors, respectively.

2. The antenna according to claim 1, wherein

said half-round and thin belt-shaped first conductors and said thin belt-shaped second conductors are provided by die-cutting a thin conductive metal plate.

3. The antenna according to claim 1, wherein

said conductive antenna element portion is formed from a pressed copper or copper alloy wire, or another conductive metal provided by performing an electrolytic plating process.

4. The antenna according to claim 1, wherein

said conductive antenna element portion is formed from a pressed thin conductive plate having a predetermined pattern that is provided by performing an etching process.

5. The antenna according to claim 1, wherein

said conductive antenna element portion is formed from a pressed flexible wiring board having a predetermined pattern thereon.

6. The antenna according to claim 1, wherein

said conductive antenna element portion is formed by printing conductive paste.

7. The antenna according to claim 1, wherein

said conductive antenna element portion is formed from sintered conductive powder.

8. The antenna according to claim 1, wherein

one end of said approximately helical-shaped portion is joined to one end of said approximately meander-shaped portion such said approximately helical-shaped portion and said approximately meander-shaped portion are disposed on said dielectric core rod as a cascaded structure.

9. The antenna according to claim 1, wherein

said approximately helical-shaped portion is connected to said approximately meander-shaped portion near the end of said dielectric core rod by folding one end of said approximately meander-shaped portion, and

said approximately meander-shaped portion is parallel to an axis of said approximately helical-shaped portion.

10. The antenna according to claim 1, wherein

said parallel thin belt-shaped second conductors are arc-shaped and have a diameter that is substantially equal to a diameter of said approximately helical-shaped portion,

said approximately helical-shaped portion is connected to said approximately meander-shaped portion near the end of said dielectric core rod by folding one end of said approximately meander-shaped portion, and

said approximately meander-shaped portion is concentric with and spaced from said approximately helical-shaped portion.

11. The antenna according to claim 1, wherein

said feed portion and said conductive antenna element portion are formed as one piece.

12. The antenna according to claim 1, further comprising:

a dielectric radome partially covering said conductive antenna element portion and said feed portion.

13. The antenna according to claim 12, wherein

a dielectric constant of said dielectric core rod is different than a dielectric constant of said dielectric radome.

14. The antenna according to claim 12, wherein

said half-round and thin belt-shaped first conductors and said thin belt-shaped second conductors are provided by die-cutting a thin conductive metal plate.

15. The antenna according to claim 12, wherein

said conductive antenna element portion is formed from a pressed copper or copper alloy wire, or another conductive metal provided by performing an electrolytic plating process.

16. The antenna according to claim 12, wherein

said conductive antenna element portion is formed from a pressed thin conductive plate having a predetermined pattern that is provided by performing an etching process.

17. The antenna according to claim 12, wherein

said conductive antenna element portion is formed from a pressed flexible wiring board having a predetermined pattern thereon.

18. The antenna according to claim 12, wherein

said conductive antenna element portion is formed by printing conductive paste.

19. The antenna according to claim 12, wherein

said conductive antenna element portion is formed from sintered conductive powder.

20. The antenna according to claim 12, wherein

one end of said approximately helical-shaped portion is joined to one end of said approximately meander-shaped portion such said approximately helical-shaped portion and said approximately meander-shaped portion are disposed on said dielectric core rod as a cascaded structure.

21. The antenna according to claim 12, wherein

said approximately helical-shaped portion is connected to said approximately meander-shaped portion near the end of said dielectric core rod by folding one end of said approximately meander-shaped portion, and

said approximately meander-shaped portion is parallel to an axis of said approximately helical-shaped portion.

22. The antenna according to claim 12, wherein

said parallel thin belt-shaped second conductors are arc-shaped and have a diameter that is substantially equal to a diameter of said approximately helical-shaped portion,

said approximately helical-shaped portion is connected to said approximately meander-shaped portion near the end of said dielectric core rod by folding one end of said approximately meander-shaped portion, and

said approximately meander-shaped portion is concentric with and spaced from said approximately helical-shaped portion.

23. The antenna according to claim 12, wherein

said feed portion and said conductive element portion are formed as one piece.

24. A radio communication apparatus for diverse communication, comprising:

a first antenna for transmitting/receiving waves in a plurality of frequency bands, said first antenna including

(i) a conductive antenna element portion,

(ii) a feed portion for establishing electrical connections between said conductive antenna element portion and a radio-frequency circuit of the radio communication apparatus,

(iii) a dielectric core rod mechanically supporting said conductive antenna element portion, and

(iv) a dielectric radome partially covering said conductive antenna element portion and said feed portion,

wherein said conductive antenna element portion includes

(a) an approximately helical-shaped portion concentric with said dielectric core rod, and

(b) an approximately meander-shaped portion;

a second antenna for transmitting/receiving waves in a plurality of frequency bands, said second antenna including

(i) a conductive antenna element portion,

(ii) a feed portion for establishing electrical connections between said conductive antenna element portion and a radio-frequency circuit of the radio communication apparatus,

(iii) a dielectric core rod mechanically supporting said conductive antenna element portion, and

(iv) a dielectric radome partially covering said conductive antenna element portion and said feed portion,

wherein said conductive antenna element portion includes

(a) an approximately helical-shaped portion concentric with said dielectric core rod, and

(b) an approximately meander-shaped portion; and

a switch for selecting one of said first conductive antenna element portion and said second conductive antenna element portion so as to perform diverse communication.

25. An antenna for transmitting/receiving waves in a plurality of frequency bands, comprising:

a conductive antenna element portion having a resonance frequency in each of the plurality of frequency bands;

a feed portion for establishing electrical connections between said conductive antenna element portion and a radio-frequency circuit of a radio communication apparatus; and

a dielectric core rod mechanically supporting said conductive antenna element portion,

wherein said conductive antenna element portion includes

(i) a first conductor having an approximately helical shape and disposed concentrically with said dielectric core rod on a side surface of said dielectric core rod, and

(ii) a second conductor, having an approximately meander shape, electromagnetically coupled with said first conductor so as to obtain desired antenna characteristics by adjusting a coupling coefficient between said first conductor and said second conductor,

with one end of said first conductor being in contact with one end of said second conductor so as to form a single antenna element, another end of said first conductor being open, and another end of said second conductor being connected to said feed portion.

26. The antenna according to claim 25, wherein

said feed portion is at a bottom of said dielectric core rod, and

said one end of said first conductor is in contact with said one end of said second conductor near a top of said dielectric core rod.

27. The antenna according to claim 25, further comprising:

a dielectric radome partially covering said conductive antenna element portion and said feed portion.

28. The antenna according to claim 27, wherein

said feed portion is at a bottom of said dielectric core rod, and

said one end of said first conductor is in contact with said one end of said second conductor near a top of said dielectric core rod.

29. The antenna according to claim 28, wherein

a dielectric constant of said dielectric core rod is different than a dielectric constant of said dielectric radome.

30. The antenna according to claim 27, wherein

a dielectric constant of said dielectric core rod is different than a dielectric constant of said dielectric radome.

31. A radio communication apparatus capable of communication in a plurality of frequency bands, comprising:

an antenna for transmitting/receiving waves in a plurality of frequency bands, said antenna including

(i) a conductive antenna element portion having a resonance frequency in each of the plurality of frequency bands,

(ii) a feed portion for establishing electrical connections between said conductive antenna element portion and a radio-frequency circuit of the radio communication apparatus,

(iii) a dielectric core rod mechanically supporting said conductive antenna element portion, and

(iv) a dielectric radome partially covering said conductive antenna element portion and said feed portion,

wherein said conductive antenna element portion includes

(a) a first conductor having an approximately helical shape and disposed concentrically with said dielectric core rod on a side surface of said dielectric core rod, and

(b) a second conductor, having an approximately meander shape, electromagnetically coupled with said first conductor so as to obtain desired antenna characteristics by adjusting a coupling coefficient between said first conductor and said second conductor,

with one end of said first conductor being in contact with one end of said second conductor so as to form a single antenna element, another end of said first conductor being open, and another end of said second conductor being connected to said feed portion.

32. The radio communication apparatus according to claim 31, wherein

said feed portion is at a bottom of said dielectric core rod, and

said one end of said first conductor is in contact with said one end of said second conductor near a top of said dielectric core rod.

33. A radio communication apparatus capable of communication in a plurality of frequency bands, comprising:

an antenna for transmitting/receiving waves in a plurality of frequency bands, said antenna including

(i) a conductive antenna element portion having a resonance frequency in each of the plurality of frequency bands,

(ii) a feed portion for establishing electrical connections between said conductive antenna element portion and a radio-frequency circuit of a radio communication apparatus, and

(iii) a dielectric core rod mechanically supporting said conductive antenna element portion,

wherein said conductive antenna element portion includes

(a) a first conductor having an approximately helical shape and disposed concentrically with said dielectric core rod on a side surface of said dielectric core rod, and

(b) a second conductor, having an approximately meander shape, electromagnetically coupled with said first conductor so as to obtain desired antenna characteristics by adjusting a coupling coefficient between said first conductor and said second conductor,

with one end of said first conductor being in contact with one end of said second conductor so as to form a single antenna element, another end of said first conductor being open, and another end of said second conductor being connected to said feed portion.

34. The radio communication apparatus according to claim 33, wherein

feed portion is at a bottom of said dielectric core rod, and

said one end of said first conductor is in contact with said one end of said second conductor near a top of said dielectric core rod.