Low profile full wavelength meandering antenna

• US 7,936,308 B2
• Filed: 12/18/2008
• Issued: 05/03/2011
• Est. Priority Date: 12/16/2004
• Status: Expired due to Fees

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Qi, Yihong, Jarmuszewski, Perry, Man, Ying Tong
• Primary Examiner(s): Wimer; Michael C
• Application Number:
  US12/337,690
• Publication Number:
  US 20090146889A1
• Time in Patent Office: 866 Days
• Field of Search: 343/700.MS, 343/702, 343/731, 343/741, 343/744, 343/806, 343/825, 343/828, 343/895
• US Class Current: 343/702
• CPC Class Codes: H01Q 1/2275 associated to expansion card or bus, e.g. in PCMCIA, PC cards, Wireless USB
• 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 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H01Q 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength

Abstract

A low profile antenna has a meander length based on the full electrical wavelength of the signal being transmitted or received. The antenna can have either an open-loop structure or a closed-loop structure with a matching network. The low profile enables the antenna to be used in a card for a device such as a personal computer, personal digital assistant, wireless telephone and so on with minimal risk of the antenna breaking off, as compared with a prior art antenna having a higher height and thus more likelihood of being broken from its card.

Claims

1. A card that interfaces an electronic device wherein the electronic device has a device height comprising:

a card body having a width and opposing ends and a device end adapted to be inserted within the electronic device;

a loop antenna mounted perpendicular on the end opposite the device end, wherein the width of the loop antenna is about the width of the card body and a height about one-half of its width, wherein the loop antenna further comprises;

a first portion having a first straight path segment followed by a meandering path segment followed by a second straight path segment, and two ends, the meandering path segment being about 50% of the length of the first portion, and

second and third portions, each having a straight path and connected to respective ends of the first portion,

wherein the antenna is non-rotatable relative to the card, and has a generally rectangular shape with four sides, and the first, second and third portions are located along respective sides of the antenna, wherein said meandering path segment is split and a portion engages adjacent said card body and has a floating end and other end coupled to a current source or transceiver and operative as electrical delay lines and a full wavelength antenna.

2. The card of claim 1, wherein the meandering path segment of the loop antenna has a length based on the full electrical wavelength of a signal being transmitted or received.

3. The card of claim 1, wherein the loop antenna has an open-loop configuration.

4. The card of claim 1, wherein the loop antenna has a closed-loop configuration and said card further comprises a matching network coupled to the second and third portions of the loop antenna.

5. The card of claim 1, wherein the loop antenna comprises a first portion parallel to an edge of the card.

6. The card of claim 1, wherein the second and third portions of the loop antenna are perpendicular to an edge of the card.

7. The card of claim 1, wherein the loop antenna has an average gain of −

2.5 dBi or better.

8. The card of claim 1, wherein the loop antenna has a peak gain of 0.1 dBi or better.

9. The card of claim 1, wherein the loop antenna comprises fourth and fifth portions each having a meandering path, the fourth portion connected to the second portion, the fifth portion connected to the third portion, so that the first, second, third, fourth and fifth portions are in series.

10. The card of claim 1, wherein the fourth and fifth portions of the loop antenna are located along a fourth side of the antenna.

11. The card of claim 1 , wherein the meandering path segment of the loop antenna has a configuration that is one of a roman key-type meander, a sinusoidal meander, a sawtooth meander and an inverted Ω

meander.

12. A card that interfaces an electronic device wherein the electronic device has a device height comprising:

a card body having a width and opposing ends and a device end adapted to be inserted within the electronic device;

a loop antenna mounted perpendicular on the end opposite the device end, wherein the width of the loop antenna is about the width of the card body and a height about one-half of its width wherein the loop antenna further comprises;

first, second, third, fourth and fifth portions connected serially,

the first, third and fifth portions each having at least one straight path segment and one meandering segment with a fixed meander height along the length of the meandering path segment, the length of each meandering path segment being about 50% of the length of its respective portion; and

the fifth portion being coupled to a current source or transceiver, wherein the open-loop antenna is perpendicular to the card, is non-rotatable relative to the card, and has a generally rectangular shape with four sides, and the first and fifth portions are located along the first side of the open-loop antenna, the second portion is located along the second side of the open-loop antenna, the third portion is located along the third side of the open-loop antenna, and the fourth portion is located along the fourth side of the open-loop antenna, wherein said meandering path segment is split and a portion engages adjacent said card body and has a floating end and other end coupled to a current source or transceiver and operative as electrical delay lines and a full wavelength antenna.

13. The card of claim 12, wherein the first, third and fifth portions of the loop antenna are parallel to an edge of the card.

14. The card of claim 12, wherein the second and fourth portions of the loop antenna are perpendicular to an edge of the card.

15. The card of claim 12, wherein the second and fourth portions of the loop antenna have meandering paths.

16. The card of claim 12, wherein the loop antenna has an average gain of −

2.5 dBi or better.

17. The card of claim 12, wherein the second and fourth portions of the loop antenna have straight paths.