Miniaturized directional antenna

• US 6,759,988 B2
• Filed: 09/25/2002
• Issued: 07/06/2004
• Est. Priority Date: 09/29/2001
• Status: Expired due to Fees

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Purr, Thomas, Pietig, Rainer
• Primary Examiner(s): PHAN, THO GIA
• Application Number:
  US10/254,250
• Publication Number:
  US 20030063033A1
• Time in Patent Office: 650 Days
• Field of Search: 343/700.MS, 343/702, 343/829, 343/846
• US Class Current: 343/700.0MS
• CPC Class Codes: H01Q 1/245 with means for shaping the antenna pattern, e.g. in order to protect user against rf exposure
• 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 21/30 Combinations of separate antenna units operating in different wavebands and connected to a common feeder system
• CPC Class Codes: H01Q 5/40 Imbricated or interleaved structures; Combined or electromagnetically coupled arrangements, e.g. comprising two or more non-connected fed radiating elements

Abstract

A description is given of a miniaturized directional antenna with a ceramic substrate (2) having at least one resonant printed wiring structure (3, 4, 5), in particular for use in the high-frequency and microwave ranges, which antenna is particularly suitable in that an electrically conductive motherboard (1, 11) is provided on which the substrate is arranged, while the at least one printed wiring structure (3, 4, 5) extends with one end as far as the motherboard. A radiation characteristic directed largely only in a half-space is achieved thereby.

Claims

1. A directional antenna comprising:

an electrically conductive carrier plate;

a substrate, mounted on the carrier plate, that includes a top surface at a height that is measured as a distance from the carrier plate;

at least one printed wiring structure that includes;

a first printed wiring on the top surface having a length and a width, the width of the first printed wiring being substantially shorter than the length, and

a second printed wiring that couples the first printed wiring structure to the electrically conductive carrier plate;

a lead-in printed wiring structure that is configured to provide a signal to the printed wiring structure via a capacitive coupling with the printed wiring structure;

wherein

the height of the first printed wiring on the top surface from the carrier plate is substantially larger than the width of the first printed wiring, to provide a directional radiation pattern relative to the carrier plate.

2. The antenna of claim 1, wherein

the length of the first printed wiring is substantially determined by a quarter-wavelength of a resonant frequency.

3. The antenna of claim 1, wherein

the height of the first printed wiring substantially determines a bandwidth of the antenna at a resonant frequency.

4. The antenna of claim 1, wherein

the height of the first printed wiring is at least five times greater than the width of the first printed wiring.

5. The antenna of claim 1, wherein

the substrate has a depth that is substantially less than the height.

6. The antenna of claim 1, wherein

the carrier plate corresponds to a plated area on a printed circuit board.

7. The antenna of claim 1, further including

at least one other printed wiring structure that each include:

a corresponding first printed wiring on the top surface, and

a corresponding second printed wiring that couples the corresponding first printed wiring structure to the electrically conductive carrier plate;

wherein

the lead-in printed wiring structure is also configured to provide the signal to each of the at least one other printed wiring structures via a capacitive coupling with each of the at least one other printed wiring structures.

8. The antenna of claim 7, wherein

resonant frequencies of the printed wiring structure and the at least one other printing wiring structure includes at least two of:

a resonant frequency in a GSM 900 band;

a resonant frequency in a DCS 1800 band; and

a resonant frequency in a PCS 1900 band.

9. The antenna of claim 1, wherein

the lead-in printed wiring structure has a size that determines a characteristic impedance of the antenna.

10. The antenna of claim 1, wherein

the lead-in printed wiring structure provides the capacitive coupling substantially via the second printed wiring.

11. The antenna of claim 1, wherein

the substrate has at least one of:

a dielectric constant greater than one, and

a relative permeability of at least one.

12. The antenna of claim 1, wherein

the substrate includes ceramic material.

13. A communications device comprising:

a printed circuit board that includes an electrically conductive carrier plate;

a substrate, mounted on the carrier plate, that includes a top surface at a height that is measured as a distance from the carrier plate;

at least one printed wiring structure that forms a directional antenna with the carrier plate, and includes;

a first printed wiring on the top surface having a length and a width, the width of the first printed wiring being substantially shorter than the length, and

a second printed wiring that couples the first printed wiring structure to the electrically conductive carrier plate;

a lead-in printed wiring structure that is configured to provide a signal to the printed wiring structure via a capacitive coupling with the printed wiring structure;

wherein

the height of the first printed wiring on the top surface from the carrier plate is substantially larger than the width of the first printed wiring, to provide a directional radiation pattern relative to the carrier plate.

14. The communications device of claim 13, wherein

the length of the first printed wiring is substantially determined based on a quarter-wavelength of an operating frequency of the communications device.

15. The communications device of claim 13, wherein

the height of the first printed wiring is at least five times greater than the width of the first printed wiring.

16. The communications device of claim 13, wherein

a surface area of the carrier plate is substantially larger than a surface area of the first printed wiring.

17. The communications device of claim 13, further including

at least one other printed wiring structure that each include:

a corresponding first printed wiring on the top surface, and

a corresponding second printed wiring that couples the corresponding first printed wiring structure to the electrically conductive carrier plate;

wherein

the lead-in printed wiring structure is also configured to provide the signal to each of the at least one other printed wiring structures via a capacitive coupling with each of the at least one other printed wiring structures.

18. The communications device of claim 17, wherein

the communications device is configured to operate in at least two of:

a GSM 900 band;

a DCS 1800 band; and

a PCS 1900 band.

19. The communications device of claim 13, wherein the lead-in printed wiring structure provides the capacitive coupling substantially via the second printed wiring.

20. The communications device of claim 13, wherein

the substrate includes ceramic material.