Dual-band glass-mounted antenna

• US 6,215,451 B1
• Filed: 11/17/1997
• Issued: 04/10/2001
• Est. Priority Date: 11/17/1997
• Status: Expired due to Term

• Current Assignee: Andrew Corporation (CommScope Holding Company, Inc.)
• Original Assignee: Allen Telecom Inc. (CommScope Holding Company, Inc.)
• Inventors: Hadzoglou, James
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): CHEN, SHIH CHAO
• Application Number:
  US08/971,369
• Time in Patent Office: 1,240 Days
• Field of Search: 343/715, 343/713, 343/702
• US Class Current: 343/715
• CPC Class Codes: H01Q 1/1285 with capacitive feeding through the windscreen
• CPC Class Codes: H01Q 1/325 characterised by the location of the antenna on the vehicle
• CPC Class Codes: H01Q 11/08 Helical antennas
• CPC Class Codes: H01Q 5/321 within a radiating element or between connected radiating elements
• CPC Class Codes: H01Q 5/357 using a single feed point
• CPC Class Codes: H01Q 9/36 with top loading

Abstract

A dual-band glass-mounted antenna system includes a dual-band through-the-glass coupler, a matching section, and a dual-band collinear antenna element. The coupler has a portion which is secured to an interior surface of the glass, and a portion which is secured to the exterior surface of the glass at a position opposite the interior portion. Co-planer transmission line circuitry in the interior and exterior portions of the coupler cooperatively form a four-conductor transmission line operating in the “coupled microstrip line odd mode,” thereby achieving coupling of RF energy through the glass window material in two disparate frequency bands. The transmission line characteristics are selected to achieve efficient coupling and desired impedance characteristics in the cellular and PCS frequency bands. The dual-band antenna element includes upper and lower radiator sections separated by a phasing coil. A sleeve choke assembly positioned at an intermediate location in the upper radiator section is on the order of one quarter wavelength at PCS frequencies. At PCS frequencies, the choke virtually eliminates current flow beyond the base of the choke, effectively establishing a half-wave radiating section between the top of the phasing coil and the base of the choke. At cellular frequencies, the choke has little effect, and therefore the entire upper radiator section acts as a half-wave radiator. The phasing coil advantageously achieves broadband, “in-phase” radiation conditions between the upper and lower collinear radiator sections at both cellular and PCS frequencies.

Claims

1. An antenna device for use in conjunction with a dielectric material having a first surface and a second surface comprising:

a substantially planar first energy coupling means adapted for non-penetrating application to the first surface;

said first energy coupling means comprising a first electrical energy connection port and first and second dissimilar planar transmission line segments, said first and second transmission line segments abutting one another, and extending in generally opposite directions from said connection port;

a substantially planar second energy coupling means comprising a mirror image of the said first energy coupling means adapted for non-penetrating application to the second surface; and

an antenna radiating element electrically connected to said second energy coupling means;

whereby with said first energy coupling means placed against the first surface of the dielectric material, and the second energy coupling means placed against the second surface of the dielectric material, said first and second energy coupling means cooperate to couple electrical energy through the dielectric material between said first electrical energy connection port and said antenna radiating element, said antenna device being operable in at least two disparate frequency bands greater than 800 MHz, and separated by a ratio of approximately of 2;

1.

2. The antenna device of claim 1, wherein:

the first transmission line segment of both coupling means comprises a two element co-planar parallel conductor configuration having a first end and an open circuited second end, the first transmission line section having a finite conductor width and spacing geometry;

the second transmission line segment of both coupling means comprising a slotted planar conductive sheet having a first edge contiguous with the first end of said first transmission line section near said energy coupling port, and a second edge opposite said first edge, said slot extending from said first edge toward said second edge and defining a two element co-planar parallel conductor configuration and forming a short circuit at said second edge;

the first transmission line section having a characteristic impedance greater than the second transmission line section.

3. The antenna device of claim 2, further comprising:

means for exciting a coupled microstrip line odd mode among said transmission line segments.

4. The antenna device of claim 2, further comprising:

means for exciting the coupled co-planar strip line mode among said first and second transmission line segments of the first energy coupling means.

5. The antenna device of claim 1, further comprising:

means for exciting a coupled microstrip line odd mode among the transmission line segments comprising said first and second energy coupling means.

6. The antenna device of claim 1, further comprising:

means for exciting the coupled co-planar strip line mode among said first and second transmission line segments of the second energy coupling means.

7. The antenna device of claim 1 wherein said at least two disparate frequency bands comprise a first frequency band including the frequency range 824 to 894 MHz and a second frequency band including the frequency range 1850 to 1990 MHz.

8. The antenna device of claim 1 wherein said first and second coupling means are configured to provide a characteristic impedance at the connection port of the first coupling means within a predetermined impedance range throughout a first frequency band of 824 to 894 MHz and a second frequency band of 1850 to 1990 MHz.

9. The antenna device of claim 1 wherein said first coupling means comprises:

a substantially planar conductive sheet member having a longitudinal axis and at least a first peripheral edge extending in a direction transverse to the longitudinal axis;

said sheet member having a slot extending inward from said first edge;

said slot defining first and second conductor elements for each of said first and second transmission line segments on opposite sides of said slot.

10. The antenna device of claim 9 wherein said slot has a width measurable in a direction transverse to said longitudinal axis, and said slot comprises a first segment having a selected width and a second segment having a width smaller than said selected width.

11. The antenna device of claim 9 wherein said first and second transmission line segments of said first coupling means are capable of cooperating with said transmission line segments of said second energy coupling means to support on said transmission line segments a coupled co-planar strip line mode.

12. The antenna device of claim 9 wherein said first and second transmission line segments of said first coupling means are capable cooperating with said first and second transmission lines of said second energy coupling means for supporting a coupled microstrip line odd mode.

13. The antenna device of claim 9, further comprising:

means for exciting a coupled microstrip line odd mode among said transmission line segments;

means for exciting a coupled coplanar strip line mode among said first and second transmission line segments of said first energy coupling means;

means for exciting a coupled co-planar strip line mode among said first and second transmission line segments of said second energy coupling means;

said transmission line segments cooperating to exhibit an impedance characteristic at said first connection port, said impedance characteristic lying within a predetermined impedance range over at least two disparate frequency bands greater than 800 MHz, separated by a ratio in the order of 2;

1.

14. The antenna device of claim 13 wherein said at least two disparate frequency bands include the frequency range 824 to 894 MHz and the frequency range 1850 to 1990 MHz.

15. The antenna device of claim 9 wherein said first and second conductor elements are electrically shorted at a location near an end of said slot opposite said first edge.

16. The antenna device of claim 9 wherein said slot has a wide region adjacent said first edge and a narrow region adjacent an end of said slot opposite said first edge.

17. The antenna device of claim 9 wherein said electrical connection between said antenna radiating element and said second coupling means comprises a first connection point electrically connected to said first conductor element of said first and second transmission line segments of said second coupling means and a matching section conductor extending between said first connection point and said antenna radiating element;

said matching section conductor cooperating with said substantially planar sheet member of said second coupling means and operative in at least one of said at least two-frequency bands to form an impedance transforming transmission line.

18. The antenna device of claim 17 wherein said antenna radiating element comprises a lower radiating section, a dual frequency band phasing means connected to the lower radiating section, and an upper radiating section connected to said phasing means.

19. The antenna device of claim 18 wherein said phasing means comprises a helical coil, providing controlled phasing of radiator sections in said at least two disparate frequency bands greater than 800 MHz separated by a ratio in the order of 2:

1.

20. The antenna device of claim 18 wherein said upper radiating section comprises:

a linear conductor extending from said phasing means and having a first end adjacent said phasing means and a second end; and

choke means disposed at a position intermediate said first and second ends of said upper radiating section.

21. The antenna device of claim 20 wherein said choke means is operable in at least one of said frequency bands to minimize current flowing in a portion of said upper radiating section between said choke means and said second end.

22. The antenna device of claim 20 wherein said upper radiating section has an electrical length and said choke means is operable such that said electrical length at a first one of said frequency bands is approximately the same as said electrical length at a second one of said frequency bands.

23. The antenna device of claim 20 wherein said choke means comprises a substantially cylindrical sleeve surrounding a portion of said linear conductor and spaced radially therefrom.

24. The antenna device of claim 23 wherein said sleeve has a sleeve first end and a sleeve second end, said sleeve second end being electrically connected to said linear conductor.

25. The antenna device of claim 24 wherein said sleeve has an electrical length in a first one of said frequency bands of approximately one-quarter wavelength.

26. The antenna device of claim 18 wherein said phasing means is operative in at least two of said frequency bands to cause current flowing in said lower radiating section and said upper radiating section to maintain an in-phase relationship.

27. The antenna device of claim 17 wherein said radiating element comprises a linear element with an electrical length in the order of a quarter wave at the lower frequency band, and an electrical length in the order of one-half wave at the higher frequency band.

28. The antenna device of claim 9 wherein said electrical connection port comprises a first connection point electrically connected to said first conductor element of said first and second transmission line segments, and a second connection point electrically connected to second electrical conductor element of said first and second transmission line segments.

29. The apparatus of claim 1, wherein said antenna device operable in at least a first frequency band including the frequency range 824 to 894 MHz and a second frequency band including the frequency range 1850 to 1990 MHz.

30. A through-dielectric coupler adapted for use in conjunction with a dielectric material having a first surface and a second surface comprising:

a substantially planar first energy coupling means adapted for non-penetrating application to the first surface;

said first energy coupling means comprising a first electrical energy connection port, and two dissimilar, contiguous planar transmission line sections, each extending in mutually opposed directions from the energy connection port;

an essentially planar second energy coupling means adapted for non-penetrating application to the second surface;

said second energy coupling means comprising a mirror image of the first energy coupling means;

said second energy coupling means comprising a second electrical energy connection port;

said first and second energy coupling means cooperating to couple electrical energy between said first electrical energy connection port and said second electrical energy connection port through the dielectric material;

said coupler operable in at least two disparate frequency bands greater than 800 MHz, separated by a ratio in the order of 2;

1.

31. The through dielectric coupler of claim 30, said coupler configured to operate in at least a first frequency band including the frequency range 824 to 894 MHz and a second frequency band including the frequency range 1850 to 1990 MHz.

32. An antenna adapted for use in conjunction with a dielectric panel having a first surface and a second surface, the antenna comprising:

a first electrical coupling portion adapted to be installed on the first surface of the dielectric panel;

a second electrical coupling portion adapted to be installed on the second surface of the dielectric panel at a location opposite the first electrical coupling portion;

said first electrical coupling portion comprising a first radio frequency energy connection port;

said a second electrical coupling portion comprising means for mechanically supporting a radio frequency antenna radiating member, said radio frequency antenna radiating member being electrically connected to said second electrical coupling portion;

said first and second electrical coupling portions each comprising a substantially planar conductive sheet defining first and second dissimilar co-planar transmission line segments on each of said first and second electrical coupling portions configured to support a microstrip line odd mode between the transmission line segments of said first and second electrical coupling portions, and a coupled co-planar strip line mode between the transmission line segments of each of the first and second electrical coupling portions, said transmission line segments establishing an electrical coupling through said dielectric panel for radio frequency energy between said first radio frequency energy connection port and said radio frequency antenna radiating member;

said first and second electrical coupling portions and said radio frequency antenna radiating member being operable and at least two disparate frequency dance greater than 800 MHz, separated by a ratio in the quarter of 2;

1.

33. The antenna of claim 32 wherein:

said substantially planar conductive sheets of said first and second electrical coupling portions each have an inner surface and an outer surface, said inner surface being oriented to face the dielectric panel; and

said first and second electrical coupling portions further comprises an inner substantially planar insulating film layer and an outer substantially planar insulating film layer, said inner film layer being disposed adjacent said inner surface of said substantially planar conductive sheet and said outer film layer being disposed adjacent said outer surface of said substantially planar conductive sheet.

34. The antenna of claim 32 further comprising means for securing said second coupling portion to the second surface of the dielectric panel.

35. The antenna of claim 34 wherein said means for securing said second coupling portion to the second surface of the dielectric panel comprises a substantially planar adhesive layer.

36. The antenna of claim 32 wherein said second coupling portion is positioned to function as a counterpoise in at least one of said frequency bands.

37. The antenna of claim 32 wherein said first coupling portion is positioned to function as a counterpoise in at least one of said frequency bands.

38. The antenna of claim 32 wherein said second coupling portion further comprises a counterpoise extension electrically connected to said substantially planar conductive sheet of said second coupling portion.

39. The antenna of claim 32 wherein said antenna radiating element comprises a lower radiating section, a dual frequency band phasing means connected to the lower radiating section, and an upper radiating section, said upper radiating section functioning as a half-wave radiator in each of said frequency bands.

40. A dual-band antenna radiating element comprising:

a radio-frequency energy connection port;

a lower radiating section;

means for electrically coupling said radio-frequency energy connection port to said lower radiating section;

a dual frequency band phasing means connected to said lower radiating section;

and an upper radiating section connected to said phasing means;

said antenna radiating element being operable in at least two disparate frequency bands greater than 800 MHz, separated by a ratio in the order of 2;

1.

41. The dual-band antenna radiating element of claim 40 wherein said means for electrically coupling said radio-frequency energy connection port to said lower radiating section comprises:

a matching section conductor extending between said radio-frequency energy connection port to said lower radiating section; and

a substantially planar conductive segment disposed in proximity to said matching section conductor;

said matching section conductor cooperating with said substantially planar conductive segment and operative in at least one of said frequency bands to form an impedance transforming transmission line.

42. The dual-band antenna radiating element of claim 40 wherein said upper radiating section functions as a half-wave radiator in each of said frequency bands.

43. The dual-band antenna radiating element of claim 40 wherein said upper radiating section comprises:

a linear conductor extending from said phasing means and having a first end adjacent said phasing means and a second end; and

choke means disposed at a position intermediate said first and second ends of said upper radiating section.

44. The dual-band antenna radiating element of claim 43 wherein said choke means is operable in at least one of said frequency bands to minimize current flowing in a portion of said upper radiating section between said choke means and said second end.

45. The dual-band antenna radiating element of claim 43 wherein said upper radiating section has an electrical length and said choke means is operable such that said electrical length at a first one of said frequency bands is approximately the same as said electrical length at a second one of said frequency bands.

46. The dual-band antenna radiating element of claim 43 wherein said choke means comprises a substantially cylindrical sleeve surrounding a portion of said linear conductor and spaced radially therefrom.

47. The dual-band antenna radiating element of claim 46 wherein said sleeve has a sleeve first end and a sleeve second end, said sleeve second end being electrically connected to said linear conductor.

48. The dual-band antenna radiating element of claim 47 wherein said sleeve has an electrical length in a first one of said frequency bands of approximately one-quarter wavelength.

49. The dual-band antenna radiating element of claim 40 wherein said phasing means comprises a helical coil providing controlled phasing of current flowing in both said upper and lower radiating sections in two disparate frequency bands greater than 800 MHz, separated by a ratio in the order of 2:

1.

50. The dual-band antenna radiating element of claim 49 wherein said phasing means is operative in at least two of said frequency bands to cause current flowing in said lower radiating section and said upper radiating section to maintain an in-phase relationship.