Multi-Band Built-in Antenna for Independently Adjusting Resonant Frequencies and Method for Adjusting Resonant Frequencies

• US 20070236391A1
• Filed: 06/23/2005
• Published: 10/11/2007
• Est. Priority Date: 06/26/2004
• Status: Active Grant

• Current Assignee: EMW Antenna Company Limited
• Original Assignee: EMW Antenna Company Limited
• Inventors: Ryou, Byung-Hoon, Kim, Jeong-Pyo, Sung, Won-Mo
• Granted Patent: US 7,579,992 B2
• Time in Patent Office: Days
• US Class Current: 343/700.MS
• 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 21/30 Combinations of separate antenna units operating in different wavebands and connected to a common feeder system
• CPC Class Codes: H01Q 5/357 using a single feed point
• CPC Class Codes: H01Q 5/371 Branching current paths
• CPC Class Codes: H01Q 9/0421 with a shorting wall or a shorting pin at one end of the element H01Q9/0414 takes precedence

Abstract

The invention relates to built-in antenna. Specifically, a multi-band built-in antenna having plurality of resonant frequencies and a method for adjusting resonant frequencies are provided, wherein resonant frequencies are able to be adjusted independently without affecting one another, for each resonant frequencies are adjusted separately through separate radiating elements.

Claims

1. A multi-band built-in antenna, comprising:

a main radiating element connected to a ground part and a feed part, the main radiating element being parallel to a ground plane;

a secondary radiating element arranged parallel to the main radiating element; and

a connecting element connecting the main radiating element and the secondary radiating element, which defines a slit between the main radiating element and the secondary radiating element,

wherein the secondary radiating element has a length such that the antenna resonates to a first resonant frequency, and the connecting element has a width such that the antenna resonate to a second resonant frequency.

2. The multi-band built-in antenna according to claim 1,

wherein the first resonant frequency is in the frequency band used for DCN (Digital Cellular Network), and

the second resonant frequency is in the frequency band used for DMB (Digital Multimedia Broadcasting).

3. The multi-band built-in antenna according to claim 1, further comprising an additive radiating element connected to and arranged coplanar with the main radiating element,

wherein the additive radiating element has an electrical length such that the antenna resonates to a third resonant frequency.

4. The multi-band built-in antenna according to claim 3, wherein the additive radiating element is of a meander shape, and an end portion of the meander shape has a width such that the antenna resonates to the third resonant frequency.

5. The multi-band built-in antenna according to claim 3 or claim 4, wherein the additive radiating element is arranged inside the main radiating element.

6. The multi-band built-in antenna according to claim 3 or claim 4,

wherein the first resonant frequency is in the frequency band used for DCN (Digital Cellular Network),

the second resonant frequency is in the frequency band used for DMB (Digital Multimedia Broadcasting), and

the third resonant frequency is in the frequency band used for K-PCS (Korea-Personal Communications Services).

7. The multi-band built-in antenna according to any one of claims 1 to 4, further comprising a dielectric body supporting the main radiating element, the secondary radiating element and the connecting element.

8. A method for adjusting resonant frequencies of a multi-band built-in antenna comprising a main radiating element connected to a ground part and a feed part, the main radiating element being parallel to a ground plane, a secondary radiating element arranged parallel to the main radiating element, and a connecting element connecting the main radiating element and the secondary radiating element, which defines a slit between the main radiating element and the secondary radiating element, comprising:

adjusting a first resonant frequency roughly by setting total length of the main radiating element, the secondary radiating element, and the connecting element to λ

₁/4, wherein λ

₁ is a wavelength corresponding to a first target resonant frequency;

adjusting a second resonant frequency roughly by setting a length of the slit to λ

₂/4, wherein λ

₂ is a wavelength corresponding to a second target resonant frequency;

adjusting the first resonant frequency finely by adjusting a length of the secondary radiating element; and

adjusting the second resonant frequency finely by adjusting a width of the connecting element.

9. The method according to claim 8, wherein the adjusting the first resonant frequency roughly and the adjusting the second resonant frequency roughly are performed concurrently.

10. The method according to claim 8 or claim 9,

wherein the first resonant frequency is in the frequency band used for DCN (Digital Cellular Network), and

the second resonant frequency is in the frequency band used for DMB (Digital Multimedia Broadcasting).

11. A method for adjusting resonant frequencies of a multi-band built-in antenna comprising a main radiating element connected to a ground part and a feed part, the main radiating element being parallel to a ground plane, a secondary radiating element arranged parallel to the main radiating element, a connecting element connecting the main radiating element and the secondary radiating element, which defines a slit between the main radiating element and the secondary radiating element, and an additive radiating element connected to and arranged coplanar with the main radiating element, comprising:

adjusting a first resonant frequency roughly by setting total length of the main radiating element, the secondary radiating element, and the connecting element to λ

₁/4, wherein λ

₁ is a wavelength corresponding to a first target resonant frequency;

adjusting a second resonant frequency roughly by setting a length of the slit to λ

₂/4, wherein λ

₂ is a wavelength corresponding to a second target resonant frequency;

adjusting a third resonant frequency by setting an electrical length of the additive radiating element to λ

₃/4, wherein λ

₃ is a wavelength corresponding to a third target resonant frequency;

adjusting the first resonant frequency finely by adjusting a length of the secondary radiating element; and

adjusting the second resonant frequency finely by adjusting a width of the connecting element.

12. The method according to claim 11, wherein the adjusting the first resonant frequency roughly and the adjusting the second resonant frequency roughly are performed concurrently.

13. The method according to claim 11 or claim 12, wherein the additive radiating element is of a meander shape, and

the adjusting the third resonant frequency comprises adjusting the third resonant frequency finely by adjusting a width of an end portion of the meander shape.

14. The method according to claim 11 or claim 12,

wherein the first resonant frequency is in the frequency band used for DCN (Digital Cellular Network),

the second resonant frequency is in the frequency band used for DMB (Digital Multimedia Broadcasting), and

the third resonant frequency is in the frequency band used for K-PCS (Korea-Personal Communications Services).