IP Library › Granted Patent US 7,180,452

Granted Patent B2

US 7,180,452 · App. 10/895,327 · Granted Feb 20, 2007

Portable radio apparatus

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Quick Facts

Patent No.: US 7,180,452
App. No.: 10/895,327
Granted: Feb 20, 2007
Kind: B2

External Links

USPTO Patent Center↗ Full Patent PDF↗

Abstract

A portable radio apparatus capable of providing an impedance match with an antenna and a simple matching circuit for all frequency components of a frequency band to be used. A portable radio apparatus includes a whip antenna, a matching circuit, a radio section changing switch, a first frequency band receiver, and a first frequency band transmitter. A parallel inductor causing a resonance with a frequency lower than a resonance frequency of the antenna is connected in parallel to the antenna for a two-resonance characteristic to thereby conduct a wide-band operation.

Claims (245)

1. A portable radio apparatus, comprising:

an antenna for transmitting and receiving a radio signal;

a radio circuit for decoding the radio signal received via the antenna and encoding a signal to be transmitted as a radio signal via the antenna; and

a matching circuit for providing an impedance match between the antenna and the radio circuit; wherein:

the matching circuit includes at least one inductive element connected in parallel to the antenna; and

said at least one of the inductive element has a Q factor more than a predetermined value, the Q factor being expressed as follows:

Q=ωL/R

wherein R indicates a resistance component, L is an inductance component, and ω designates an angular frequency of the radio signal.

2. A portable radio apparatus in accordance with claim 1 , wherein:

the matching circuit is a π type circuit in which a first inductive element is connected in parallel on the side of the antenna and a second inductive element is connected in parallel on the side of the radio circuit; and

the first inductive element has a Q factor more than a Q factor of the second inductive element.

3. A portable radio apparatus in accordance with claim 2 , wherein:

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands; and

the antenna has different two resonance frequencies in one of the frequency bands.

4. A portable radio apparatus in accordance with claim 2 , wherein:

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands; and

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic.

5. A portable radio apparatus in accordance with claim 2 , further comprising:

a detector for detecting whether the antenna is in an expanded state in which the antenna is expanded; and

an expansion matching circuit impedance of which matches with the antenna in the expanded state in a particular frequency band when the expansion matching circuit is connected to the matching circuit; wherein:

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands;

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic; and

the expansion matching circuit is connected to the matching circuit when the antenna is in the expanded state and a particular one of the frequency bands is selected.

6. A portable radio apparatus in accordance with claim 2 , further comprising:

a detector for detecting whether the antenna is in an expanded state in which the antenna is expanded; and

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands;

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic;

the expansion matching circuit is connected to the matching circuit when the antenna is in the expanded state and a particular one of the frequency bands is selected; and

impedance of the antenna in the expanded state matches that of the matching circuit in a frequency band for which the expansion matching circuit is not connected to the matching circuit.

7. A portable radio apparatus in accordance with claim 1 , wherein:

the first inductive element has a Q factor more than a Q factor of the second inductive element; and

the Q factor of the first inductive element takes a value, which sets radiation efficiency of the antenna to a value equal to or more than a predetermined value when the radio signal is transmitted.

8. A portable radio apparatus in accordance with claim 7 , wherein:

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands; and

the antenna has different two resonance frequencies in one of the frequency bands.

9. A portable radio apparatus in accordance with claim 7 , wherein:

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands; and

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic.

10. A portable radio apparatus in accordance with claim 7 , further comprising:

a detector for detecting whether the antenna is in an expanded state in which the antenna is expanded; and

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands;

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic; and

the expansion matching circuit is connected to the matching circuit when the antenna is in the expanded state and a particular one of the frequency bands is selected.

11. A portable radio apparatus in accordance with claim 7 , further comprising:

a detector for detecting whether the antenna is in an expanded state in which the antenna is expanded; and

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands;

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic;

the expansion matching circuit is connected to the matching circuit when the antenna is in the expanded state and a particular one of the frequency bands is selected; and

impedance of the antenna in the expanded state matches that of the matching circuit in a frequency band for which the expansion matching circuit is not connected to the matching circuit.

12. A portable radio apparatus in accordance with claim 1 , wherein:

the first inductive element has a Q factor more than a Q factor of the second inductive element; and

the Q factor of each of the first and second inductive elements takes a value, which sets radiation efficiency of the antenna to a value equal to or more than a predetermined value when the radio signal is transmitted.

13. A portable radio apparatus in accordance with claim 12 , wherein:

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands; and

the antenna has different two resonance frequencies in one of the frequency bands.

14. A portable radio apparatus in accordance with claim 12 , wherein:

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands; and

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic.

15. A portable radio apparatus in accordance with claim 12 , further comprising:

a detector for detecting whether the antenna is in an expanded state in which the antenna is expanded; and

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands;

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic; and

the expansion matching circuit is connected to the matching circuit when the antenna is in the expanded state and a particular one of the frequency bands is selected.

16. A portable radio apparatus in accordance with claim 12 , further comprising:

a detector for detecting whether the antenna is in an expanded state in which the antenna is expanded; and

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands;

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic;

the expansion matching circuit is connected to the matching circuit when the antenna is in the expanded state and a particular one of the frequency bands is selected; and

impedance of the antenna in the expanded state matches that of the matching circuit in a frequency band for which the expansion matching circuit is not connected to the matching circuit.

17. A portable radio apparatus in accordance with claim 1 , wherein the Q factor of each of the inductive elements is more than 40.

18. A portable radio apparatus in accordance with claim 17 , wherein:

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands; and

the antenna has different two resonance frequencies in one of the frequency bands.

19. A portable radio apparatus in accordance with claim 17 , wherein:

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands; and

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic.

20. A portable radio apparatus in accordance with claim 17 , further comprising:

a detector for detecting whether the antenna is in an expanded state in which the antenna is expanded; and

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands;

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic; and

the expansion matching circuit is connected to the matching circuit when the antenna is in the expanded state and a particular one of the frequency bands is selected.

21. A portable radio apparatus in accordance with claim 17 , further comprising:

a detector for detecting whether the antenna is in an expanded state in which the antenna is expanded; and

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands;

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic;

the expansion matching circuit is connected to the matching circuit when the antenna is in the expanded state and a particular one of the frequency bands is selected; and

impedance of the antenna in the expanded state matches that of the matching circuit in a frequency band for which the expansion matching circuit is not connected to the matching circuit.

22. A portable radio apparatus in accordance with claim 1 , wherein:

the first inductive element has a Q factor more than a Q factor of the second inductive element; and

the Q factor of each of the inductive elements is more than 40.

23. A portable radio apparatus in accordance with claim 22 , wherein:

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands; and

the antenna has different two resonance frequencies in one of the frequency bands.

24. A portable radio apparatus in accordance with claim 22 , wherein:

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands; and

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic.

25. A portable radio apparatus in accordance with claim 22 , further comprising:

a detector for detecting whether the antenna is in an expanded state in which the antenna is expanded; and

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands;

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic; and

the expansion matching circuit is connected to the matching circuit when the antenna is in the expanded state and a particular one of the frequency bands is selected.

26. A portable radio apparatus in accordance with claim 22 , further comprising:

a detector for detecting whether the antenna is in an expanded state in which the antenna is expanded; and

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands;

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic;

the expansion matching circuit is connected to the matching circuit when the antenna is in the expanded state and a particular one of the frequency bands is selected; and

impedance of the antenna in the expanded state matches that of the matching circuit in a frequency band for which the expansion matching circuit is not connected to the matching circuit.

27. A portable radio apparatus in accordance with claim 22 , wherein the matching circuit is a π type circuit in which a first capacitive element is connected in parallel on the side of the antenna and a second capacitive element is connected in parallel on the side of the radio circuit.

28. A portable radio apparatus in accordance with claim 27 , wherein:

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands; and

the antenna has different two resonance frequencies in one of the frequency bands.

29. A portable radio apparatus in accordance with claim 27 , wherein:

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands; and

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic.

30. A portable radio apparatus in accordance with claim 27 , further comprising:

a detector for detecting whether the antenna is in an expanded state in which the antenna is expanded; and

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands;

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic; and

the expansion matching circuit is connected to the matching circuit when the antenna is in the expanded state and a particular one of the frequency bands is selected.

31. A portable radio apparatus in accordance with claim 27 , further comprising:

a detector for detecting whether the antenna is in an expanded state in which the antenna is expanded; and

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands;

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic;

the expansion matching circuit is connected to the matching circuit when the antenna is in the expanded state and a particular one of the frequency bands is selected; and

impedance of the antenna in the expanded state matches that of the matching circuit in a frequency band for which the expansion matching circuit is not connected to the matching circuit.

32. A portable radio apparatus in accordance with claim 1 , wherein:

the first inductive element has a Q factor more than a Q factor of the second inductive element;

the Q factor of the first inductive element takes a value, which sets radiation efficiency of the antenna to a value equal to or more than a predetermined value when the radio signal is transmitted; and

the Q factor of each of the inductive elements is more than 40.

33. A portable radio apparatus in accordance with claim 32 , wherein:

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands; and

the antenna has different two resonance frequencies in one of the frequency bands.

34. A portable radio apparatus in accordance with claim 32 , wherein:

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands; and

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic.

35. A portable radio apparatus in accordance with claim 32 , further comprising:

a detector for detecting whether the antenna is in an expanded state in which the antenna is expanded; and

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands;

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic; and

the expansion matching circuit is connected to the matching circuit when the antenna is in the expanded state and a particular one of the frequency bands is selected.

36. A portable radio apparatus in accordance with claim 32 , further comprising:

a detector for detecting whether the antenna is in an expanded state in which the antenna is expanded; and

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands;

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic;

the expansion matching circuit is connected to the matching circuit when the antenna is in the expanded state and a particular one of the frequency bands is selected; and

impedance of the antenna in the expanded state matches that of the matching circuit in a frequency band for which the expansion matching circuit is not connected to the matching circuit.

37. A portable radio apparatus in accordance with claim 1 , wherein:

the first inductive element has a Q factor more than a Q factor of the second inductive element;

the Q factor of each of the inductive elements is more than 40.

38. A portable radio apparatus in accordance with claim 37 , wherein:

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands; and

the antenna has different two resonance frequencies in one of the frequency bands.

39. A portable radio apparatus in accordance with claim 37 , wherein:

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands; and

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic.

40. A portable radio apparatus in accordance with claim 37 , further comprising:

a detector for detecting whether the antenna is in an expanded state in which the antenna is expanded; and

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands;

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic; and

the expansion matching circuit is connected to the matching circuit when the antenna is in the expanded state and a particular one of the frequency bands is selected.

41. A portable radio apparatus in accordance with claim 37 , further comprising:

a detector for detecting whether the antenna is in an expanded state in which the antenna is expanded; and

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands;

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic;

the expansion matching circuit is connected to the matching circuit when the antenna is in the expanded state and a particular one of the frequency bands is selected; and

impedance of the antenna in the expanded state matches that of the matching circuit in a frequency band for which the expansion matching circuit is not connected to the matching circuit.

42. A portable radio apparatus in accordance with claim 1 , wherein:

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands; and

the antenna has different two resonance frequencies in one of the frequency bands.

43. A portable radio apparatus in accordance with claim 1 , wherein:

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands; and

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic.

44. A portable radio apparatus in accordance with claim 1 , further comprising:

a detector for detecting whether the antenna is in an expanded state in which the antenna is expanded; and

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands;

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic; and

the expansion matching circuit is connected to the matching circuit when the antenna is in the expanded state and a particular one of the frequency bands is selected.

45. A portable radio apparatus in accordance with claim 1 , further comprising:

a detector for detecting whether the antenna is in an expanded state in which the antenna is expanded; and

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands;

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic;

the expansion matching circuit is connected to the matching circuit when the antenna is in the expanded state and a particular one of the frequency bands is selected; and

impedance of the antenna in the expanded state matches that of the matching circuit in a frequency band for which the expansion matching circuit is not connected to the matching circuit.

46. A portable radio apparatus comprising:

an antenna for transmitting and receiving a radio signal;

a radio circuit for decoding the radio signal received via the antenna and encoding a signal to be transmitted as a radio signal via the antenna;

a matching circuit for providing an impedance match between the antenna and the radio circuit, the matching circuit including at least one capacitive element connected in parallel to the antenna;

a detector for detecting whether the antenna is in an expanded state in which the antenna is expanded; and

the radio circuit is a circuit for decoding and encoding the radio signal in a plurality of frequency bands;

the antenna has different two resonance frequencies in one of the frequency bands;

the antenna includes a straight section and a helical section, the helical section having a two-resonance characteristic; and

the expansion matching circuit is connected to the matching circuit when the antenna is in the expanded state and a particular one of the frequency bands is selected.

47. A portable radio apparatus in accordance with claim 46 , wherein

impedance of the antenna in the expanded state matches that of the matching circuit in a frequency band for which the expansion matching circuit is not connected to the matching circuit.

Assignments (1)

ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 11, 2014

From: NEC CORPORATION

To: LENOVO INNOVATIONS LIMITED (HONG KONG)

Reel/Frame 033720/0767 →