Antenna device and mobile communication unit

• US 6,388,625 B1
• Filed: 01/03/2000
• Issued: 05/14/2002
• Est. Priority Date: 03/19/1998
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Oohara, Masahiro, Yuda, Naoki, Fukushima, Susumu
• Primary Examiner(s): LE, HOANGANH T
• Application Number:
  US09/424,270
• Time in Patent Office: 862 Days
• Field of Search: H01/Q.124, H01/Q.136, 343/702, 343/895, 343/901
• US Class Current: 343/702
• CPC Class Codes: H01Q 1/241 used in mobile communications, e.g. GSM H01Q1/247, H01Q1/248 take precedence
• 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 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 11/08 Helical antennas
• CPC Class Codes: H01Q 19/28 using a secondary device in the form of two or more substantially straight conductive elements log- periodic antennas H01Q11/10; constituting a reflecting surface H01Q19/10
• CPC Class Codes: H01Q 5/378 Combination of fed elements with parasitic elements
• CPC Class Codes: H01Q 5/385 Two or more parasitic elements
• CPC Class Codes: H01Q 5/392 the parasitic elements having dual-band or multi-band characteristics

Abstract

An antenna device used in mobile communication apparatus such as cellular phones, and which achieves good transmission and reception of information in more than one frequency band. Easy and wide ranging adjustment of the impedance properties of the antenna as well as their productive mass production is allowed. The antenna device includes a) a spiral-shaped first antenna element (1) of which one end is open and the other end is electrically connected to a high frequency circuit inside a communication terminal; and b) a second antenna element (2) having both ends being open, and which is insulated from and disposed on either outer or inner surface of the first antenna element (1). The impedance properties of an antenna can be adjusted by changing the disposing position of the second antenna element (2).

Claims

1. A dual frequency antenna device comprising;

a) a spiral-shaped first antenna element of which a first end is open and a second end is electrically coupled to a circuit; and

b) a second antenna element having both ends being open, said second antenna element being insulated from said first antenna element, said second antenna element having a meandering shaped conductive section which changes direction more than two times;

wherein said first and said second antenna elements resonate respectively in a first frequency in a first frequency band and a second frequency in a second frequency band, the second frequency being higher than the first frequency, the meandering shaped conductive section of said second antenna element extending lengthwise parallel to a center axis of said spiral-shaped first antenna element.

2. The dual frequency antenna device as defined in claim 1, wherein said second antenna element is disposed at a predetermined position to obtain desired impedance properties.

3. The dual frequency antenna device as defined in claim 1, wherein at least one of said first and said second antenna elements are made of material containing at least one of silver, copper, beryllium copper, phosphor bronze, brass, aluminum, nickel and steel.

4. The dual frequency antenna device as defined in claim 1, wherein at least once of said first and said second antenna elements have a surface thereof plated with material containing at least one of silver, copper, beryllium copper, phosphor bronze, brass, aluminum, nickel and steel.

5. The dual frequency antenna device as defined in claim 1, wherein cross sections of said first and said second antenna elements are approximately circular or polygonal.

6. The dual frequency antenna device as defined in claim 1, wherein resin is situated between said first and said second antenna elements.

7. The dual frequency antenna device as defined in claim 1, wherein at least one of said first and said second antenna elements has insulation film on a surface thereof.

8. The dual frequency antenna device as defined in claim 1, wherein said first antenna element is molded with resin on an inner surface or an outer surface thereof, further, on the top of which, at least a portion of said second antenna element is plated.

9. The dual frequency antenna device as defined in claim 1, wherein a pattern of said second antenna element is plated on a film or flexible thin film resin, and which wraps and is fixed to an outer surface or an inner surface of said spiral-shaped first antenna element in such a manner that insulation between said first and said second antenna element is maintained.

10. The dual frequency antenna device as defined in claim 1, wherein a pattern of said second antenna element is formed with conductive paste on a film or flexible thin film resin, and which wraps and is fixed to an outer surface or an inner surface of said spiral-shaped first antenna element in such a manner that insulation between said first and said second antenna element is maintained.

11. The dual frequency antenna device as defined in claim 1, wherein said first and said second antenna elements are disposed inside of a housing of a communication terminal.

12. The dual frequency antenna device defined in claim 1, wherein said antenna device is included in a mobile communication apparatus.

13. An antenna device comprising;

a) a spiral-shaped first antenna element of which one end is open and the other end is electrically coupled to a circuit;

b) a second antenna element with both ends are open, and which is insulated from said first antenna element; and

c) a third antenna element placed such that it can slide inside said first antenna element;

wherein electricity is supplied only to said third antenna element when said third antenna element is moved through said first antenna element in an upward position, and through said third antenna element, resonance occurs in the first and second frequency bands via a switch, and when the third antenna element is in a downward position, electricity is supplied only to said first antenna element, and through said first and said second antenna elements, resonance occurs respectively in the first and second frequency bands via the switch.

15. The dual frequency antenna device as defined in claim 13, wherein said third antenna element is constructed with a spiral-shaped element.

16. The dual frequency antenna device as defined in claim 13, wherein said first and said second antenna elements are disposed inside of a housing of a communication terminal.

17. The dual frequency antenna device defined in claim 13, wherein said antenna device is included in a mobile communication apparatus.

18. The antenna device as defined in claim 13, wherein said second antenna element includes a meandering shape conductive section, said meandering shaped conductive section extending lengthwise parallel to a center axis of said spiral-shaped first antenna element.

14. The dual frequency antenna device as defined in claim, wherein said third antenna element is constructed with a bar-shaped element.

19. An antenna device comprising:

a) a spiral-shaped first antenna element of which a first end is open and a second end is electrically coupled to a circuit;

b) a second element with both ends being open, said second antenna element being insulated from said first antenna element, said second antenna element having a meandering shaped conductive section, the meandering shaped conductive section of said second antenna element extending lengthwise parallel to a center axis of said spiral-shaped first antenna element; and

c) a third antenna element placed such that it can slide inside said first antenna element;

wherein electricity is supplied only to said first and said third antenna elements when said third antenna element is in an upward position, and through said third antenna element, resonance occurs in the first and second frequency bands via a switch, and when said third antenna element is in a downward position, electricity is supplied only to said first antenna element, and through said first and said second antenna elements, resonance occurs respectively in the first and second frequency bands via the switch.

20. The dual frequency antenna device as defined in claim 19, wherein said third antenna element is constructed with a bar-shaped element.

21. The dual frequency antenna device as defined in claim 19, wherein said third antenna element is constructed with a spiral-shaped element.

22. The dual frequency antenna device as defined in claim 19, wherein said first and said second antenna elements are disposed inside of a housing of a communication terminal.

23. The dual frequency antenna device defined in claim 19, wherein said antenna device is included in a mobile communication apparatus.

24. An antenna device comprising;

a) a spiral-shaped first antenna element of which a first end is open and a second end is electrically coupled to a circuit;

b) a second antenna element with both ends being open, said second antenna element being insulated from said first antenna element, said second antenna element having a meandering shaped conductive section, the meandering shaped conductive section of said second antenna element extending lengthwise parallel to a center axis of said spiral-shaped first antenna element; and

c) a third antenna element having said first and said second antenna element integrally formed on the top thereof, and which is placed such that it can slide inside a housing of a communication terminal;

wherein electricity is supplied only to said third antenna element when said third antenna element is in an upward position, and through said third antenna element, resonance occurs in the first and second frequency bands via a switch, and when said third antenna element is stored, electricity is supplied only to said first antenna element, and through said first and said second antenna elements, resonance occurs respectively in the first and second frequency bands via the switch.

25. The dual frequency antenna device as defined in claim 24, wherein said third antenna element is constructed with a bar-shaped element.

26. The dual frequency antenna device as defined in claim 24, wherein said third antenna element is constructed with a spiral-shaped element.

27. The dual frequency antenna device defined in claim 24, wherein said antenna device is included in a mobile communication apparatus.

28. A dual frequency antenna device comprising;

a) a spiral-shaped first antenna element of which a first end is open and a second end is electrically coupled to a circuit; and

b) a second antenna element changing directions more than twice and comprising a conductive plate and having both ends being open, said second antenna element being insulated from said first antenna element;

wherein said first and said second antenna elements resonate respectively in a first frequency in a first frequency band and a second frequency in a second frequency band, the second frequency being higher than the first frequency.

29. The dual frequency antenna device as defined in claim 28, wherein said conductive plate is longer than a half of an outer or an inner periphery of said first antenna element.

30. The dual frequency antenna device as defined in claim 28, wherein said conductive plate comprises a hollow circular cylinder of which an inner diameter is larger than an outer diameter of said first antenna element, or an outer diameter is smaller than an inner diameter of said first antenna element.