Double resonance antenna structure for several frequency ranges

• US 6,140,966 A
• Filed: 07/02/1998
• Issued: 10/31/2000
• Est. Priority Date: 07/08/1997
• Status: Expired due to Term

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Mobile Phones UK Limited (Nokia Corporation)
• Inventors: Pankinaho, Ilkka
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): CHEN, SHIH CHAO
• Application Number:
  US09/109,572
• Time in Patent Office: 852 Days
• Field of Search: 343/700 MS, 343/702, 343/846, 343/826, 343/828, 343/876
• US Class Current: 343/700.0MS
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 5/35 using two or more simultaneously fed points
• 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
• CPC Class Codes: H01Q 9/0442 with particular tuning means
• CPC Class Codes: H01Q 9/0478 with means for suppressing spurious modes, e.g. cross polarisation
• CPC Class Codes: H01Q 9/14 Length of element or elements adjustable telescopic elements H01Q1/10
• CPC Class Codes: H04B 1/005 adapting radio receivers, transmitters andtransceivers for operation on two or more bands, i.e. frequency ranges
• CPC Class Codes: H04B 1/406 with more than one transmission mode, e.g. analog and digital modes

Abstract

The invention relates to small-sized antenna systems, especially planar antenna structures operating on several frequency bands. The antenna structure of the invention comprises a radiating antenna element with at least two lips. Thus, the antenna structure has two basic resonance frequencies, which are defined by the dimensions of the lips of the antenna element, gaps between them, and the other dimensions of the antenna structure. The radiating antenna structure is connected to the ground plane at least at one place. The radiating antenna element comprises at least two connection points, which are used for connecting the feed lines of the transmitter and receiver, and for connecting special tuning elements. The resonance frequencies of the antenna structure may be adjusted by connecting the said tuning elements to the connection points and antenna feed lines so that the antenna structure is operable on more than two frequency bands. The switches may be conventional semiconductor switches, such as FET switches or PIN diodes. Various optionally connectable tuning element or antenna feed arrangements may be used for carrying out an antenna arrangement which may be tuned in on all reception and transmission bands of an arrangement with several frequency ranges and mobile phone systems.

Claims

1. An antenna structure for use in a multiband device, comprising a planar antenna element and a ground plane so that the said antenna element is short-circuited to the ground plane at least at one place, characterized in that said antenna element has at least two separate resonance frequencies, and that said antenna element has at least two connection points for connecting feed lines of the antenna, so that the antenna structure works in at least two TX-frequency bands and two RX-frequency bands of at least two wireless systems.

2. The antenna structure of claim 1, characterized in that it additionally comprises at least two lips forming different resonance frequencies.

3. The antenna structure of claim 1, characterized in that it additionally comprises at least one tuning element for changing the resonance frequency of the antenna structure.

4. The antenna structure of claim 3, characterized in that at least one of said at least one tuning element is connected between one of said two connection points of the antenna element and the ground plane.

5. The antenna structure of claim 4, characterized in that at least one of the at least one tuning element forms part of the feed line of the antenna.

6. The antenna structure of claim 3, characterizeed in that it additionally comprises at least one switch for selectively connecting at least one of said at least one tuning element to the antenna structure.

7. The antenna structure of claim 3, characterized in that it additionally comprises at least one switch for selectively connecting more than one transmitter feed line to a connection point of said antenna element.

8. The antenna structure of claim 3, characterized in that it additionally comprises at least one switch for selectively connecting more than one receiver feed line to a connection point of the antenna element.

9. A mobile station, the antenna arrangement of which comprises a radiating antenna element and a ground plane, characterized in that said antenna element has at least two connection points for connecting the feed lines, and that the said antenna element further comprises at least one switch and at least one tuning element, said at least one tuning element being connectable to the connection point of the antenna element with said at least one switch for changing at least one resonance frequency of the antenna arrangement.

10. An antenna structure for use in a multiband device having a planar antenna element and a ground plane, the antenna element being short-circuited to the ground plane at least at one place, wherein the antenna element has

at least two connection points in the antenna element for connection of the feed lines of the antenna structure,

at least two lips in the antenna element for forming at least two separate resonance frequency bands of the antenna structure, and the antenna structure further has at least one tuning element for changing a resonance frequency of the antenna structure, so that the antenna structure works in at least two TX-frequency bands and two RX-frequency bands of at least two wireless systems.

11. The antenna structure of claim 10 wherein at least one slot is formed between the lips.

12. The antenna structure of claim 11 wherein a second slot separates the lips.

13. The antenna structure of claim 12 wherein the second slot is arranged in a "T" shaped formation with respect to the at least one slot.

14. The antenna structure of claim 13 further including a hole in each of the lips for the purpose of widening the width of the resonant frequency bands formed by the lips.

15. The antenna structure of claim 13 further including a notch in each of the lips for the purpose of widening the width of the resonant frequency bands formed by the lips.