Apparatus and method for enhancing low-frequency operation of mobile communication antennas

• US 20040125029A1
• Filed: 02/27/2003
• Published: 07/01/2004
• Est. Priority Date: 08/28/2000
• Status: Active Grant

• Current Assignee: In4Tel Ltd.
• Original Assignee: In4Tel Ltd.
• Inventors: Kadichevitz, Michael, Maoz, Joseph
• Granted Patent: US 6,940,460 B2
• Time in Patent Office: Days
• US Class Current: 343/702
• CPC Class Codes: H01Q 1/242 specially adapted for hand-held use
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/48 Earthing means; Earth screens; Counterpoises
• CPC Class Codes: H01Q 13/106 Microstrip slot antennas patch antenna elements H01Q9/0407
• CPC Class Codes: H01Q 9/0407 Substantially flat resonant element parallel to ground plane, e.g. patch antenna dipole H01Q9/285; monopole H01Q9/40
• 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

Abstract

The operation of a mobile communication apparatus is enhanced particularly in the lower frequency portion of its bandwidth by connecting an electrically-conductive reflector to the electrically-conductive ground of the printed wired board (PWB) containing the communication circuitry such that the reflector effectively enlarges the ground of the PWB to load the antenna in the lower portion of its radio frequency band. The reflector may include stub reflectors integrally formed on the PWB, or connected thereto, preferably at the end of the PWB opposite to that connected to the antenna. The antenna may be an internal antenna or an external antenna.

Claims

1. Mobile communication apparatus, comprising:

a housing including communication circuitry and a printed wired board (PWB) formed with a signal terminal for an antenna, and an electrically-conductive ground for said communication circuitry;

an antenna carried by said housing and electrically connected to said signal terminal of the communication circuitry in the PWB, said antenna being designed to operate in at least one radio frequency band;

and an electrically-conductive reflector carried by said PWB and electrically connected to said electrically-conductive ground of the PWB such that said electrically-conductive reflector effectively enlarges said ground of the PWB to load the antenna in said radio frequency band, and thereby to enhance the operating efficiency of the antenna particularly in the lower part of said radio frequency band, and/or to widen said radio frequency band.

2. The apparatus according to claim 1, wherein said antenna is connected to the signal terminal of the communication circuitry at one end of the PWB, and said electrically-conductive reflector is connected to the ground of the communication circuitry at the opposite end of said PWB.

3. The apparatus according to claim 2, wherein said reflector is carried on a separate board from said PWB and is electrically connected to the ground of the communication circuitry at said opposite end of the PWB.

4. The apparatus according to claim 3, wherein said reflector board is fixed to said PWB and underlies said opposite end of the PWB.

5. The apparatus according to claim 3, wherein said reflector board is fixed to said PWB and overlies said opposite end of the PWB.

6. The apparatus according to claim 3, wherein said reflector board is integrally formed with said PWB at said opposite end thereof, and is folded with respect to said opposite end of the PWB.

7. The apparatus according to claim 1, wherein said ground of the communication circuitry is carried on one layer of said PWB, and said reflector is carried on another layer of said PWB.

8. The apparatus according to claim 1, wherein said signal terminal of the communication circuitry is on one layer of the PWB at one end thereof, and said reflector is carried on another layer of the PWB at the opposite end thereof.

9. The apparatus according to claim 1, wherein said reflector includes at least one stub reflector carried by said PWB.

10. The apparatus according to claim 1, wherein said signal terminal of the communication circuitry is at one end of the PWB, and said reflector includes at least one stub reflector at the opposite end of the PWB.

11. The apparatus according to claim 10, wherein said reflector includes a pair of stub reflectors formed in the electrically-conductive ground of the PWB at said opposite end of the PWB.

12. The apparatus according to claim 11, wherein said opposite end of the PWB includes an electrically-conductive ground on one layer of the PWB, said stub reflectors being defined by slots formed in the electrically-conductive ground on said one layer.

13. The apparatus according to claim 12, wherein said PWB includes an electrically-conductive ground on a second layer of the PWB, said second layer being formed with interruptions in said electrically-conductive ground, which interruptions are aligned with said stub reflectors in said one layer.

14. The apparatus according to claim 12, wherein said stub reflectors include electrically-conductive portions on another layer of said PWB to which said stub reflectors are electrically connected.

15. The apparatus according to claim 1, wherein said electrically-conductive reflector is included in a box having a plurality of sides overlying one end of the PWB, at least one of said sides of the box being electrically-conductive and serving as the reflector electrically connected to said ground of the PWB.

16. The apparatus according to claim 15, wherein a plurality of said sides of said electrically-conductive reflector box are electrically-conductive and serve as the reflector electrically connected to said ground of the PWB.

17. The apparatus according to claim 15, wherein said at least one electrically-conductive side of said reflector box is formed with at least one slot to modify the load produced by said reflector box.

18. The apparatus according to claim 1, wherein said antenna is an internal antenna within said housing and is electrically connected to said PWB within said housing.

19. The apparatus according to claim 1, wherein said antenna is an external antenna carried by said housing externally thereof and is electrically connected to said PWB within said housing.

20. The apparatus according to claim 1, wherein said antenna is electrically connected to the ground of said PWB, in addition to its connection to the signal terminal of said PWB.

21. The apparatus according to claim 1, wherein said mobile communication apparatus is a mobile telephone handset and includes a housing having two sections movable relative to each other, one of said housing sections including said PWB, communication circuitry, and signal terminal for an antenna, the other of said housing sections including said electrically-conductive reflector.

22. The apparatus according to claim 21, wherein said other housing section is pivotal with respect to said one housing section.

23. A method of enhancing the operational efficiency of a mobile communication apparatus in at least one radio frequency band, or to widen its radio frequency band, which apparatus comprises a housing including communication circuitry and a printed wired board (PWB) formed with a signal terminal for an antenna and an electrically-conductive ground for said communication circuitry, and an antenna carried by said housing and electrically connected to said signal terminal of the communication circuitry in the PWB;

characterized in that the operating efficiency of the antenna is enhanced, particularly in the lower portion of said radio frequency band, or its radio frequency band is widened by connecting an electrically-conductive reflector to said electrically-conductive ground of the PWB such that said electrically-conductive reflector effectively enlarges said ground of the PWB to load the antenna in said radio frequency band.

24. The method according to claim 23, wherein said antenna is connected to the signal terminal of the communication circuitry at one end of the PWB, and said electrically-conductive reflector is connected to the ground of the communication circuitry at the opposite end of said PWB.

25. The method according to claim 24, wherein said reflector is carried on a separate board from said PWB and is electrically connected to said opposite end of the PWB.

26. The method according to claim 23, wherein said ground of the communication circuitry is carried on one layer of said PWB, and said reflector is carried on another layer of said PWB.

27. The method according to claim 23, wherein said signal terminal of the communication circuitry is on one layer of the PWB at one end thereof, and said reflector is carried on another layer of the PWB at the opposite end thereof.

28. The method according to claim 23, wherein said reflector includes at least one stub reflector carried by said PWB.

29. The method according to claim 23, wherein said antenna is an internal antenna within said housing and is electrically connected to said PWB within said housing.

30. The method according to claim 23, wherein said antenna is an external antenna carried by said housing externally thereof and is electrically connected to said PWB within said housing.

31. The method according to claim 23, wherein said antenna is electrically connected to the ground of said PWB, in addition to its connection to the signal terminal of said PWB.

32. The method according to claim 23, wherein said mobile communication apparatus is a mobile telephone handset and includes a housing having two sections movable relative to each other, one of said housing sections including said PWB, communication circuitry, and signal terminal for an antenna, the other of said housing sections including said electrically-conductive reflector.

33. The method according to claim 23, wherein said electrically-conductive reflector is formed with slots to modify the load produced thereby.