Compact, low profile, single feed, multi-band, printed antenna

• US 6,856,294 B2
• Filed: 01/05/2004
• Issued: 02/15/2005
• Est. Priority Date: 09/20/2002
• Status: Expired due to Fees

• Current Assignee: Laird Technologies Incorporated (DuPont de Nemours, Inc.)
• Original Assignee: Centurion Industries Incorporated (Laird Limited)
• Inventors: Kadambi, Govind Rangaswamy, Yarasi, Sripathi, Hebron, Theodore Samuel
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): A, Minh Dieu
• Application Number:
  US10/752,376
• Publication Number:
  US 20040140938A1
• Time in Patent Office: 407 Days
• Field of Search: 343/702, 343/784, 343/785, 343/789, 343/845, 343/911.R, 343/700.MS
• US Class Current: 343/702
• CPC Class Codes: H01Q 1/243 with built-in antennas
• 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 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

Abstract

Printed circuit techniques and two-shot molding techniques are used to form a metal radiating element, a metal ground plane element, a metal antenna feed, a metal short-circuiting strip and metal capacitive loading plates within small antennas that are buried within transmit/receive radio-devices such a mobile cellular telephones. Balanced and unbalanced, single-feed, two and three band antennas are provided wherein the radiating element is laterally spaced from the ground plane element, to thereby provide an antenna having a very low profile or height, including antennas wherein the ground plane element and the radiating element are placed coplanar on the same surface of a PCB. A thin dielectric carriage on a PCB allows for the metal capacitive loading plates to be placed on the sidewalls of the dielectric carriage, to thereby provide reactive loading of a radiating element that is on the top surface of the dielectric carriage.

Claims

1. A physically compact radio-device, comprising:

a printed circuit board having a metal ground plane located on a relatively large-area portion of a surface of said printed circuit board;

circuitry for said radio-device physically associated with said ground plane, said ground plane providing a common-electrical-ground connection for said circuitry;

a thin dielectric carriage located on a relatively small-area portion of said surface of said printed circuit board, wherein said small-area portion of said printed circuit board abuts said relatively large-area portion of said printed circuit board;

said dielectric carriage having a plurality of sidewalls whose top surfaces define a top surface of said dielectric carriage and whose bottom surfaces define a bottom surface of said dielectric carriage;

said top surface of said dielectric carriage being generally parallel to said bottom surface of said dielectric carriage;

said bottom surface of said dielectric carriage being located on said second relatively small-area portion of said surface of said printed circuit board;

a metal antenna element on said dielectric carriage, said antenna element being located above and being laterally spaced from, said ground plane;

at least one metal loading strip connected to at least one portion of said antenna element and extending along at least one sidewall of said dielectric carriage; and

a metal antenna feed strip extending from a first portion of said antenna element to said circuitry.

2. The physically compact radio-device of claim 1 wherein said antenna element is (1) located on said top surface of said dielectric carriage so as to be generally parallel to, but not coplanar with, said ground plane, or (2) located on said sidewalls of said dielectric carriage so as to be located above and generally perpendicular to the plane of said ground plane.

3. The physically compact radio-device of claim 2 wherein said antenna element is formed in a geometric configuration that provides multi-band response for said physically compact radio-device.

4. The physically compact radio-device of claim 3 wherein said antenna element is in the form spiral metal pattern.

5. The physically compact radio-device of claim 4 wherein said spiral metal pattern comprises a generally rectangular spiral having a plurality of generally straight metal segments.

6. The physically compact radio-device of claim 5 including a generally L-shaped metal segment extending from one of said plurality of metal segments.

7. The physically compact radio-device of claim 6 wherein said dielectric carriage has a height of about 3 mm as measured between said top surface and said bottom surface of said dielectric carriage.

8. The physically compact radio-device of claim 7 wherein said dielectric carriage has a height of about 3 mm as measured between said top surface and said bottom surface of said dielectric carriage.

9. The physically compact radio-device of claim 7 wherein said generally rigid dielectric material is selected from a group consisting of polycarbonate, ABS and HDPE.

10. The physically compact radio-device of claim 7 wherein said antenna element is located on said top surface of said dielectric carriage so as to be generally parallel to said ground plane, or wherein said antenna element is located on said sidewalls of said dielectric carriage so as to be generally perpendicular to said ground plane.

11. The physically compact radio-device of claim 6 wherein said antenna element is located on said top surface of said dielectric carriage so as to be generally parallel to said ground plane, or wherein said antenna element is located on said sidewalls of said dielectric carriage so as to be generally perpendicular to said ground plane.

12. The physically compact radio-device of claim 1 including:

a short-circuiting metal strip directly connecting a second portion of said antenna element to said ground plane, said second portion of said antenna element being physically spaced from said first portion of said antenna element.

13. The physically compact radio-device of claim 12 wherein said antenna element is formed in a geometric configuration that provides multi-band response for said physically compact mobile radio-device.

14. The physically compact radio-device of claim 13 wherein said dielectric carriage has a height of about 3 mm as measured between said top surface and said bottom surface of said dielectric carriage.

15. The physically compact radio-device of claim 1 wherein said dielectric carriage is constructed of a generally rigid dielectric material having a dielectric constant in the range of from about 2.5 to about 3.0.

16. A physically compact antenna, comprising:

a printed circuit board having a metal ground plane located on a relatively large-area portion of a surface of said printed circuit board;

a thin dielectric carriage located on a relatively small-area portion of said surface of said printed circuit board, wherein said small-area portion of said printed circuit board abuts said relatively large-area portion of said printed circuit board;

said dielectric carriage having a plurality of sidewalls whose top surfaces define a top surface of said dielectric carriage and whose bottom surfaces define a bottom surface of said dielectric carriage;

said top surface of said dielectric carriage being generally parallel to said bottom surface of said dielectric carriage;

said bottom surface of said dielectric carriage being located on said second relatively small-area portion of said surface of said printed circuit board;

a gap formed in one of said sidewalls of said dielectric carriage;

a metal antenna element formed on said sidewalls of said dielectric carriage so as to extend through said gap and so as to be located on both an inner surface and an outer surface of said sidewalls;

said antenna element being located above, being laterally spaced from, and extending generally perpendicular to said ground plane; and

a metal antenna feed strip extending from said antenna element.

17. A physically compact antenna, comprising:

a printed circuit board having a metal ground plane located on a relatively large-area portion of a surface of said printed circuit board;

a thin dielectric carriage located on a relatively small-area portion of said surface of said printed circuit board, wherein said small-area portion of said printed circuit board abuts said relatively large-area portion of said printed circuit board;

said dielectric carriage having a plurality of sidewalls whose top surfaces define a top surface of said dielectric carriage and whose bottom surfaces define a bottom surface of said dielectric carriage;

said top surface of said dielectric carriage being generally parallel to said bottom surface of said dielectric carriage;

said bottom surface of said dielectric carriage being located on said second relatively small-area portion of said surface of said printed circuit board;

a first metal radiating element on said top surface of said dielectric carriage, said first radiating element being located above, being laterally spaced from, and extending generally parallel to said ground plane; and

a second metal radiating element formed on said sidewalls of said dielectric carriage, said second radiating element being located above, being laterally spaced from, and extending generally perpendicular to said ground plane.