Antenna for flat radio device

• US 7,136,019 B2
• Filed: 11/25/2003
• Issued: 11/14/2006
• Est. Priority Date: 12/16/2002
• Status: Expired due to Fees

• Current Assignee: Pulse Finland Oy (Yageo Corporation)
• Original Assignee: Pulse Finland Oy (Yageo Corporation)
• Inventors: Lepistö, Tommi, Mikkola, Jyrki
• Primary Examiner(s): Ho, Tan
• Application Number:
  US10/722,650
• Publication Number:
  US 20040113845A1
• Time in Patent Office: 1,085 Days
• Field of Search: 343/700.MS, 343/702, 343/815, 343/860, 343/833, 343/834
• US Class Current: 343/702
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 19/005 Patch antenna using one or more coplanar parasitic elements
• CPC Class Codes: H01Q 5/371 Branching current paths
• CPC Class Codes: H01Q 5/378 Combination of fed elements with parasitic elements
• CPC Class Codes: H01Q 5/392 the parasitic elements having dual-band or multi-band characteristics
• CPC Class Codes: H01Q 9/0442 with particular tuning means
• CPC Class Codes: H01Q 9/40 Element having extended radiating surface
• CPC Class Codes: H01Q 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength

Abstract

An antenna intended to be used in a small-sized and flat radio device, and to a radio device which has an antenna according to the invention. The base element of the antenna is a monopole-type conductor (110) internal to the device. This conductor may be designed such that the harmonic nearest to the fundamental resonating frequency can be utilized in providing an upper operating band. In addition to the base element the antenna structure comprises a parasitic element (120) which functions as both an auxiliary radiator and antenna matching element. Matching is optimized using an inductive component (125) which connects the parasitic element to signal ground. The antenna gain achieved is considerably higher than that of known antenna structures occupying the same space (h), and the antenna matching is improved, compared to known internal monopole antennas.

Claims

1. An internal antenna for a flat radio device having a signal ground, the antenna comprising:

a monopole-type base element with a feed conductor;

a parasitic element functioning as an auxiliary radiator; and

a single inductive matching element connected between the parasitic element and the signal ground to optimize antenna matching.

2. An antenna according to claim 1, said radio device having a circuit board, and the base element and the parasitic element being substantially on top of one another as viewed along the direction of the normal of said circuit board.

3. An antenna according to claim 2, the base element and the parasitic element being rigid conductive wires aside said circuit board as viewed along the direction of the normal of the circuit board.

4. An antenna according to claim 2, the parasitic element being a conductive strip on a surface of said circuit board and the base element being a rigid conductive piece.

5. An antenna according to claim 4, the matching element being a conductive strip on a surface of said circuit board.

6. An antenna according to claim 2, the base element being a conductive strip on a surface of said circuit board and the parasitic element being a rigid conductive piece.

7. An internal antenna for a flat radio device having a signal ground,the antenna comprising:

a monopole-type base element with a feed conductor, wherein said base element has a first branch and a second branch, between which branches being an electromagnetic coupling to set the ratio of the fundamental resonating frequency and its nearest harmonic of the base element such that the fundamental resonating frequency falls into frequency range of a first radio system and said nearest harmonic falls into frequency range of a second radio system;

a parasitic element functioning as an auxiliary radiator; and

a single matching element connected between the parasitic element and the signal ground to optimize antenna matching.

8. An antenna according to claim 7, wherein a structure constituted of the parasitic element and the matching element has a first resonating frequency arranged to fall into frequency range of the first radio system, and a second resonating frequency arranged to fall into frequency range of the second radio system.

9. An internal antenna for a flat radio device having a signal ground, the antenna comprising:

a monopole-type base element with a feed conductor;

a parasitic element functioning as an auxiliary radiator; and

a single matching element connected between the parasitic element and the signal ground to optimize antenna matching, wiherein the matching element is a wound conductive wire.

10. A radio device having a signal ground and an internal antenna, comprising:

a monopole-type base element with a feed conductor;

a parasitic element functioning as auxiliary radiator; and

a single inductive matching element connected between the parasitic element and the radio device signal ground to optimize antenna matching.

11. A radio device having a signal ground and an internal antenna, comprising:

a monopole-type base element with a feed conductor;

a parasitic element functioning as an auxiliary radiator;

a single matching element connected between the parasitic element and the radio device signal ground to optimize antenna matching; and

the radio device having a first part and a second part such that these parts can be turned on a hinge one upon another, said antenna being located within the first part.

12. An internal antenna for a flat radio device having a signal ground, the antenna comprising:

a monopole-type base element including a feed conductor;

a parasitic element functioning as an auxiliary radiator;

a single matching element connected between the parasitic element and the signal ground to optimize antenna matching; and

the flat radio device includes a circuit board;

wherein the base element and the parasitic element are substantially on top of one another as viewed along the direction of the normal of said circuit board.

13. An antenna according to claim 12, wherein the base element and the parasitic element are rigid conductive wires disposed aside said circuit board as viewed along the direction of the normal of the circuit board.

14. An antenna according to claim 13, wherein the matching element is a conductive strip on a surface of said circuit board.

15. An antenna according to claim 12, wherein the parasitic element is a conductive strip on a surface of said circuit board, and the base element is a rigid conductive piece.

16. An antenna according to claim 12, wherein the base element is a conductive strip on a surface of said circuit board, and the parasitic element is a rigid conductive piece.