Window antenna for a motor vehicle

• US 6,377,221 B1
• Filed: 08/30/2000
• Issued: 04/23/2002
• Est. Priority Date: 08/31/1999
• Status: Expired due to Term

• Current Assignee: Delphi Delco Electronics Europe GmbH (Aptiv PLC)
• Original Assignee: Fuba Automotive GmbH & Co. KG.
• Inventors: Hopf, Jochen, Lindenmeier, Heinz, Reiter, Leopold
• Primary Examiner(s): PHAN, THO GIA
• Application Number:
  US09/651,612
• Time in Patent Office: 601 Days
• Field of Search: H01/Q.132, H01/Q 1.310, 343/711, 343/713, 343/704, 343/712, 343/725
• US Class Current: 343/713
• CPC Class Codes: H01Q 1/1271 for mounting on windscreens
• CPC Class Codes: H01Q 23/00 Antennas with active circuits or circuit elements integrated within them or attached to them

Abstract

The invention relates to an antenna on the window of a motor vehicle having a thin electrically conductive layer which is transparent for light, but reduces heat transmission. The window is formed by a window pane which can be lowered into the bottom part of a vehicle door, and can be moved by a window lifter. The pane is covered with an area having a limited conductivity formed by a layer of limited conductivity. An antenna connection point is formed between a horizontal sealing strip placed at the lower border of the window aperture and the window lifter in a free area which exists when the window is closed. The connection point is connected by high-frequency, low-loss means to the area of limited conductivity.

Claims

1. An antenna for mounting on a windowpane of a lowerable window of a motor vehicle having a window lifter for raising and lowering the window and a receiver coupled to the antenna, said antenna comprising:

(a) a thin, electrically low conductive layer transparent to light and capable of reducing the transmission of heat through the windowpane, said layer being disposed on the window and forming an area of limited conductivity on the windowpane;

(b) a horizontal sealing strip disposed on a lower border of the windowpane; and

(c) an antenna connection point formed between said horizontal sealing strip and the window lifter, said antenna connection point high frequency coupled to said low conductive layer.

2. The antenna according to claim 1, further comprising:

(a) a ground point on the vehicle; and

(b) at least one antenna cable having a first lead connected to said antenna connection point and a second lead connected to the ground point.

3. The antenna according to claim 2, wherein the ground point is disposed on the window lifter and is conductively connected to the vehicle.

4. The antenna according to claim 2, wherein the ground point is disposed at an end of said antenna cable.

5. The antenna according to claim 1, further comprising a border region formed in the periphery of the windowpane of the motor vehicle having a conductive window frame, said border region being disposed adjacent to and uncovered by said low conductive layer so as to reduce the capacitance between said low conductive layer and the window frame.

6. The antenna according to claim 1, wherein said antenna further comprises at least one substantially flat electrode made of highly conductive material high frequency coupled to said low conductive layer and to said antenna connection point, said at least one electrode disposed adjacent to at least one edge of said low conductive layer and being sufficiently long so as to minimize the loss created by said edge of said low conductive layer.

7. The antenna according to claim 6, wherein said at least one electrode is selected from the group consisting of an elongated narrow strip and a wire extending substantially parallel to said horizontal sealing strip and having galvanic contact to said area of limited conductivity, said at least one electrode being sufficiently long so as to minimize losses from said at least one electrode.

8. The antenna according to claim 6, wherein said antenna further comprises a dielectrically active layer made from plastic films, said dielectrically active layer having two surfaces, wherein said area of limited conductivity and said at least one electrode are applied on different surfaces of said dielectrically active layer, wherein the high frequency connection between said at least one electrode and said area of limited conductivity is made capacitively, and wherein the width of said at least one electrode is sufficiently long so as to create a capacitive connection of sufficiently low impedance.

9. The antenna according to claim 1 further comprising an antenna amplifier coupled to said antenna connection point, said antenna being designed as an LMS antenna having a high capacitive impedance.

10. The antenna according to claim 1, wherein said antenna comprises a free area disposed along the bottom edge of the windowpane, adjacent to the window lifter.

11. The antenna according to claim 10, further comprising at least two electrodes separated from each other and distributed within the free area to form a diversity antenna array on the windowpane.

12. The antenna according to claim 1, wherein said windowpane has at least two glass panels and said low conductive layer is laminated on an inner surface of one of the at least two panels of the windowpane.

13. The antenna according to claim 1, wherein the windowpane has at least two glass panels and said low conductive layer is laminated on a transparent plastic film embedded between the at least two panels of the windowpane.

14. An USW/LMS antenna unit comprising:

(a) at least one LMS antenna for mounting on a windowpane of a motor vehicle having a window lifter for raising and lowering the window and a receiver coupled to the antenna, said LMS antenna comprising

(i) a thin, electrically low conductive layer transparent to light and capable of reducing the transmission of heat through the windowpane, said layer being disposed on the window and forming an area of limited conductivity on the windowpane;

(ii) a horizontal sealing strip disposed on a lower border of the windowpane; and

(iii) an antenna connection point formed between said horizontal sealing strip and the window lifter, said antenna connection point high frequency coupled to said low conductive layer; and

(b) a USW antenna array having a USW antenna unit for mounting in the vicinity of a heated rear windowpane of the vehicle and an antenna cable connected to said USW antenna unit,

wherein the received LMS signals are combined in said USW antenna unit.

15. The USW/LMS antenna unit according to claim 14, wherein said at least one LMS antenna comprises at least two LMS door antennas mounted in at least two different doors of the same motor vehicle, each door antenna being coupled to said USW antenna unit and further comprising a summation circuit coupled to said at least two door antennas for combining the LMS signals to obtain one LMS signal.

16. An antenna for mounting on a windowpane of a lowerable window of a motor vehicle having a window lifter for raising and lowering the window, a receiver coupled to the antenna and a ground point, said antenna comprising:

(a) a thin, electrically low conductive layer transparent to light and capable of reducing the transmission of heat through the windowpane, said layer being disposed on the window and forming an area of limited conductivity on the windowpane;

(b) a horizontal sealing strip disposed on a lower border of the windowpane;

(c) an antenna connection point formed between said horizontal sealing strip and the window lifter, said antenna connection point high frequency coupled to said low conductive layer; and

(d) at least one antenna cable having a first lead connected to said antenna connection point and a second lead connected to the ground point;

wherein said antenna comprises a first broad-band antenna for the LMS/USW and TV frequency bands disposed on the window of one of the vehicle doors, and at least one other antenna for the USW and TV frequency bands on at least one other window of another vehicle door, said at least one antenna cable being coupled to a diversity antenna device installed in the vehicle.

17. A lowerable window assembly for a motor vehicle having a receiver comprising

(a) a lowerable window;

(b) a window lifter coupled to said window for raising and lowering said window; and

(c) an antenna mounted on a windowpane of said lowerable window and coupled to the receiver, said antenna comprising;

(i) a thin, electrically low conductive layer transparent to light and capable of reducing the transmission of heat through the windowpane, said layer being disposed on the window and forming an area of limited conductivity on the windowpane;

(ii) a horizontal sealing strip disposed on a lower border of the windowpane; and

(iii) an antenna connection point formed between said horizontal sealing strip and said window lifter, said antenna connection point high frequency coupled to said low conductive layer.