IE83339B1 - A radio receiver - Google Patents
A radio receiverInfo
- Publication number
- IE83339B1 IE83339B1 IE1999/1114A IE991114A IE83339B1 IE 83339 B1 IE83339 B1 IE 83339B1 IE 1999/1114 A IE1999/1114 A IE 1999/1114A IE 991114 A IE991114 A IE 991114A IE 83339 B1 IE83339 B1 IE 83339B1
- Authority
- IE
- Ireland
- Prior art keywords
- radio receiver
- antenna
- ground
- circuit board
- printed circuit
- Prior art date
Links
- 239000002184 metal Substances 0.000 claims description 9
- 239000000463 material Substances 0.000 claims description 7
- 239000004020 conductor Substances 0.000 claims description 3
- 239000007769 metal material Substances 0.000 claims description 2
- 230000002708 enhancing Effects 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 230000001702 transmitter Effects 0.000 description 2
- 238000010276 construction Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000002828 fuel tank Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
Description
A radio receiver
The present invention relates to a radio receiver, and in particular, though not limited
to radio receiver for use in a vehicle, for example, for use in connection with a
security system, such as a keyless entry security system of a motor vehicle.
Keyless entry systems for motor vehicles are well known, as are security systems for
motor vehicles. Security systems in general comprise a central electronic control unit
which in general, controls a number of circuits of the security system. For example,
the central control unit may control a vehicle immobiliser for immobilising the vehicle
by, for example, isolating the ignition system of the vehicle from the battery, and/or
by isolating the fuel injection or carburation system of the vehicle from the fuel tank.
The central control unit, in general, also controls an alarm circuit for sounding an
alarm in the event of an unauthorised entry or an attempted unauthorised entry
being made to the vehicle. It is also common for the central control unit to operate a
control circuit for the central locking system of the vehicle.
In general, when the security system controls the central locking system of the
vehicle, the security system is provided as a keyless entry system, and is thus armed
and disarmed by reception of a radio frequency signal, which typically, is transmitted
by a key fob transmitter. In such cases, the central electronic control unit comprises
a radio receiver for receiving the transmitted signal, or alternatively, a stand alone
radio receiver may be provided which inputs the received signal to the central
electronic control unit. In general, the radio receiver, whether it is provided in a stand
alone form or incorporated in the central electronic control unit is located in the
vehicle, and typically, within the engine compartment. in which case components of
the radio receiver are subjected to significant interference from the electrical and
electronic systems of the motor vehicle. Such interference can lead to failure of the
security system, and may also lead to false alarms. Additionally, such interference
may also interfere with the reception of arming and disarming signals by the radio
receiver. While attempts have been made to minimise the effects of such
interference, such attempts have not been entirely successful.
There is therefore a need for a radio receiver which overcomes the problems of
known receivers.
The present invention is directed towards providing such a radio receiver, as well as
a security system for a vehicle incorporating the radio receiver, and the present
invention is also directed towards an antenna for a radio receiver.
According to the invention there is provided a radio receiver for a security system of
a motor vehicle, the radio receiver comprising a printed circuit board having a
plurality of electronic components mounted thereon connected by electrically
conductive tracks printed thereon forming a radio receiving circuit, and an antenna
formed by an electrically conductive track on the printed circuit board for receiving
radio frequency signals, the antenna being electrically connected to the radio
receiving circuit, an electrically conductive shielding means located on the printed
circuit board for shielding the components thereon, and an electrically conductive
connecting means extending directly from the shielding means for connecting the
shielding means to ground, the connecting means being adapted for connecting to a
grounded portion of the vehicle.
Preferably, the connecting means is adapted for connecting directly to the body of
the vehicle.
In one embodiment of the invention the connecting means comprises a ground lug
extending from the shielding means. Preferably, the connecting means is integrally
formed with the shielding means. Advantageously, an opening is provided in the
connecting means for accommodating a screw for connecting and securing the
connecting means to ground. Ideally, the connecting means is formed from sheet
material. Preferably, the sheet material forming the connecting means is sheet
metal.
In one embodiment of the invention the connecting means is of length at least
mm. Preferably, the connecting means is of length approximately 40mm.
In another embodiment of the invention the connecting means is of width at least
mm. Preferably, the connecting means is of width approximately 12mm.
In one embodiment of the invention an electrically conductive ground plane is formed
on the printed circuit board on the side opposite to that on which the components are
mounted.
In another embodiment of the invention the shielding means is electrically connected
to the ground plane so that the components on the printed circuit board are
completely enshrouded by a combination of the shielding means and the ground
plane.
In a further embodiment of the invention a securing means is provided for securing
the shielding means to the printed circuit board. Preferably, the securing means is
adapted for extending through the printed circuit board for securing the shielding
means to the printed circuit board. Advantageously, the securing means are of
electrically conductive material. Ideally, the securing means is integrally formed with
the shielding means. Preferably, the securing means is adapted for electrically
engaging the ground plane.
In one embodiment of the invention the securing means comprises a plurality of
securing tabs.
In another embodiment of the invention the shielding means comprises a housing,
and preferably, the housing is formed of sheet metal material.
In one embodiment of the invention the housing comprises a top wall and a pair of
spaced apart side walls extending from the top wall, and a pair of spaced apart end
walls extending from the top wall between the side walls and joining the respective
side walls, and preferably, at least one securing means extends from each side wall
and each end wall.
In another embodiment of the invention the shielding means is located relative to the
antenna such that a part of the shielding means acts to form a ground referencing
means for the antenna.
In a further embodiment of the invention the antenna is printed on the printed circuit
board on the same side as the components. Preferably, the antenna is connected to
the radio receiving circuit by an electrically conductive track extending between the
antenna and the radio receiving circuit. Advantageously, the antenna is printed on
the printed circuit board on a portion thereof which extends outwardly of the
shielding means. Ideally, the antenna is printed on the printed circuit board relatively
closely to the shielding means.
In one embodiment of the invention the spacing between the shielding means and
the antenna does not exceed 10mm.
In another embodiment of the invention the spacing between the shielding means
and the antenna does not exceed 5mm.
Additionally or alternatively the ground referencing means is electrically connected to
and extends from the shielding means adjacent to but spaced apart from the
antenna. Preferably, the ground referencing means is of electrically conductive sheet
material.
in one embodiment of the invention the ground referencing means comprises a
ground reference panel extending from the shielding means. Preferably, the ground
reference panel extends parallel to the printed circuit board on which the antenna is
printed. Advantageously, the ground referencing means is of area at least equal to
the area of the printed circuit board taken up by the antenna, and preferably, the
ground referencing means is of area greater than the area of the printed circuit board
taken up by the antenna.
in one embodiment of the invention the spacing between the ground referencing
means and the antenna lies in the range of 10mm to 30mm.
in another embodiment of the invention the spacing between the ground referencing
means and the antenna lies in the range of 12mm to 20mm.
In a further embodiment of the invention the spacing between the ground referencing
means and the antenna is approximately 15mm.
in one embodiment of the invention the radio receiver is adapted for mounting in a
vehicle.
In another embodiment of the invention the radio receiver is adapted for use in
conjunction with a central electronic control unit of a security system of a motor
vehicle.
Further the invention provides a security system for a vehicle, the security system
comprising the radio receiver according to the invention.
The invention will be more clearly understood from the following description of some
preferred embodiments thereof which are given by way of example only with
reference to the accompanying drawings, in which:
Fig. 1 is a perspective view of a radio receiver according to the invention,
Fig. 2 is another perspective view of the radio receiver of Fig. 1,
Fig. 3 is a perspective view of a portion of the radio receiver of Fig. 1,
Fig. 4 is a perspective view of another portion of the radio receiver of Fig. 1,
Fig. 5 is a perspective view similar to Fig. 1 of a radio receiver according to
another embodiment of the invention.
Referring to the drawings and initially to Figs. 1 to 4 there is illustrated a radio
receiver, according to the invention indicated generally by the reference numeral 1.
The radio receiver 1 is particularly suitable for mounting in a motor vehicle for use
with an electronic central control unit of a security system for receiving arming and
disarming signals from a key fob transmitter for arming and disarming the security
system. The radio receiver 1 comprises a printed circuit board 2 having a top side 3
and a bottom side 4. The top side 3 of the printed circuit board 2 is patterned with
electrically conductive tracks 5 in an area 6 for interconnecting a plurality of
components 7 which form a radio receiving circuit. An antenna 8 which is formed by
an electrically conductive track 9 printed on the top side 3 of the printed circuit board
2 in an area 14 is connected to the radio receiving circuit by one end of the
electrically conductive track 9. Such construction of a radio receiver printed circuit
board will be well known to those skilled in the art.
A shielding means for electrically shielding the components on the printed circuit
board 2 comprises an electrically conductive sheet metal housing 10 mounted on the
top side 3 of the printed circuit board 2 in the area 6. The housing 10 is integrally
formed in one piece from a sheet of sheet metal and comprises a top wall 11 and a
pair of spaced apart side walls 12 extending from the top wall 11, and spaced apart
end walls 13 also extending from the top wall 11, and joining the side walls 12. The
area of the top wall 11 is such as to completely enclose the area 6 containing the
radio receiving circuit so that the entire circuitry of the radio receiver 1, with the
exception of the antenna 8 is shielded by the housing 10.
An electrically conductive ground plane 15 is printed on the bottom side 4 of the
board 2 and covers an area slightly greater than the area covered by the housing 10.
A securing means which comprises two electrically conductive securing tabs 16
extending from each of the side and end walls 12 and 13 through openings 17 in the
printed circuit board 2 secure the housing 10 to the printed circuit board 2. The
securing tabs 16 electrically engage the ground plane 15 so that the components 7
and electrically conductive tracks 5 in the area 6 of the radio receiving circuit are
completely enclosed by the housing 10 in combination with the ground plane 15. In
this way the components 7 and the electrically conductive tracks 5 in the area 6 are
completely electrically shielded from external interference and emissions. The
securing tabs 16 are of sheet metal and are integrally formed with the housing 8
from the same sheet of sheet metal.
An electrically conductive connecting means for grounding the housing 10 to the
vehicle comprises a ground lug 18 which extends from the housing 10 and is
integrally formed therewith from the same sheet of sheet metal. An opening 19
extending through the ground lug 18 is provided for receiving a screw for securing
the ground lug 18‘directly onto a grounded portion of the vehicle, typically, the
vehicle body. The ground lug 18 extends a distance of approximately 40mm from the
housing 10 and is of width approximately 12mm. The provision of the ground lug 18
ensures that the housing 10 is adequately grounded, and furthermore, that the
ground plane 15 is also adequately grounded.
Additionally, the housing 10 is located relatively closely to the antenna 8 for acting as
a ground referencing means for the antenna 8 for providing the antenna 8 with a
ground reference. This it has been found in many cases significantly enhances the
performance of the radio receiver 1, and in particular, enhances the reception of
radio frequency signals by the receiver 1. In this embodiment of the invention the
end wall 13 which is closest to the antenna 8 is approximately 5mm from the nearest
track of the antenna 8. it is believed that the significant enhancement of reception of
radio frequency signals by the radio receiver 1 is provided by a combination of the
proximity of the housing 10 to the antenna 8 and the fact that a particularly good
grounding of the housing 10 is achieved by the provision of the ground lug 18.
Referring now to Fig. 5 of the drawings a radio receiver according to another
embodiment of the invention which is indicated generally by the reference numeral
is illustrated. The radio receiver 30 is also suitable for mounting in a motor vehicle
for use with an electronic central control unit of a security system, and is
substantially similar to the radio receiver 1, and similar components are identified by
the same reference numerals. The main difference between the radio receiver 30
and the radio receiver 1 is that in this embodiment of the invention the ground
referencing means is provided by an electrically conductive ground reference panel
31 extending from the housing 10. The ground reference panel 31 is integrally
formed with the housing 10 of the same sheet metal as the housing 10. The ground
reference panel 31 extends substantially parallel to the plane of the antenna 8 and is
spaced apart therefrom a distance of approximately 15mm.
As well as the housing 10, the ground reference panel 31 forms an additional ground
reference for the antenna 8, and it has been found that the provision of the ground
reference in the form of the ground reference panel 31 in many cases enhances
reception of radio frequency signals by the receiver 1, and minimises the effect of
interference on the antenna. Although, in certain cases preferred results are
achieved without the ground reference panel 31. In cases where it is desirable to
provide the ground reference panel 31, it has been found in particular that where the
area of the ground reference panel 31 is similar to or greater than the area of the
printed circuit board 2 taken up by the antenna 8 particularly good results are
achieved. The area of the printed circuit board 2 taken up by the antenna 8 is
indicated by the broken lines 14, and as can be seen, the area of the ground
reference panel 31 in this embodiment of the invention is greater than the area
bounded by the broken lines 14.
While the shielding means and the ground referencing means have been described
as being provided by an electrically conductive metal, the shielding means and the
ground referencing means may be provided by any other suitable electrically
conductive material, for example, metallised plastics material or the like. It will also of
course be appreciated that while it is preferable to provide a ground plane on the
bottom side of the printed circuit board, and to electrically connect the shielding
means thereto so that the radio receiving circuit is completely electrically shielded,
the ground plane may be omitted from the printed circuit board.
Claims (42)
1. A radio receiver for a security system of a motor vehicle, the radio receiver comprising a printed circuit board having a plurality of electronic components mounted thereon connected by electrically conductive tracks printed thereon forming a radio receiving circuit, and an antenna formed by an electrically conductive track on the printed circuit board for receiving radio frequency signals, the antenna being electrically connected to the radio receiving circuit, an electrically conductive shielding means located on the printed circuit board for shielding the components thereon, and an electrically conductive connecting means extending directly from the shielding means for connecting the shielding means to ground, the connecting means being adapted for connecting to a grounded portion of the vehicle.
2. A radio receiver as claimed in Claim 1 in which the connecting means is adapted for connecting directly to the body of the vehicle.
3. A radio receiver as claimed in Claim 1 or 2 in which the connecting means comprises a ground lug extending from the shielding means.
4. A radio receiver as claimed in any preceding claim in which the connecting means is integrally formed with the shielding means.
5. A radio receiver as claimed in any preceding claim in which an opening is provided in the connecting means for accommodating a screw for connecting and securing the connecting means to ground.
6. A radio receiver as claimed in any preceding claim in which the connecting means is formed from sheet material.
7. A radio receiver as claimed in Claim 6 in which the sheet material forming the connecting means is sheet metal.
8. A radio receiver as claimed in any preceding claim in which the connecting means is of length at least 30mm.
9. A radio receiver as claimed in Claim 8 in which the connecting means is of length approximately 40mm.
10. A radio receiver as claimed in any preceding claim in which the connecting means is of width at least 10mm.
11. A radio receiver as claimed in Claim 10 in which the connecting means is of width approximately 12mm.
12. A radio receiver as claimed in any preceding claim in which an electrically conductive ground plane is formed on the printed circuit board on the side opposite to that on which the components are mounted.
13. A radio receiver as claimed in Claim 12 in which the shielding means is electrically connected to the ground plane so that the components on the printed 20 circuit board are completely enshrouded by a combination of the shielding means and the ground plane.
14. A radio receiver as claimed in any preceding claim in which a securing means is provided for securing the shielding means to the printed circuit board.
15. A radio receiver as claimed in Claim 14 in which the securing means is adapted for extending through the printed circuit board for securing the shielding means to the printed circuit board.
16. A radio receiver as claimed in Claim 14 or 15 in which the securing means are of electrically conductive material.
17. A radio receiver as claimed in any of Claims 14 to 16 in which the securing means is integrally formed with the shielding means.
18. A radio receiver as claimed in any of Claims 14 to 17 in which the securing means is adapted for electrically engaging the ground plane.
19. A radio receiver as claimed in any of Claims 14 to 18 in which the securing means comprises a plurality of securing tabs.
20. A radio receiver as claimed in any preceding claim in which the shielding means comprises a housing.
21. A radio receiver as claimed in Claim 20 in which the housing is formed of sheet metal material.
22. A radio receiver as claimed in Claim 20 or 21 in which the housing comprises a top wall and a pair of spaced apart side walls extending from the top wall, and a pair of spaced apart end walls extending from the top wall between the side walls and joining the respective side walls.
23. A radio receiver as claimed in Claim 22 in which at least one securing means extends from each side wall and each end wall.
24. A radio receiver as claimed in any preceding claim in which the shielding means is located relative to the antenna such that a part of the shielding means acts to form a ground referencing means for the antenna.
25. A radio receiver as claimed in Claim 24 in which the antenna is printed on the printed circuit board on the same side as the components.
26. A radio receiver as claimed in Claim 24 or 25 in which the antenna is connected to the radio receiving circuit by an electrically conductive track extending between the antenna and the radio receiving circuit. 16
27. A radio receiver as claimed in any of Claims 24 to 26 in which the antenna is printed on the printed circuit board on a portion thereof which extends outwardly of the shielding means.
28. A radio receiver as claimed in any of Claims 24 to 27 in which the antenna is printed on the printed circuit board relatively closely to the shielding means.
29. A radio receiver as claimed in any of Claims 24 to 28 in which the spacing between the shielding means and the antenna does not exceed 10mm.
30. A radio receiver as claimed in Claim 29 in which the spacing between the shielding means and the antenna does not exceed 5mm.
31. A radio receiver as claimed in any of Claims 24 to 30 in which the ground referencing means is electrically connected to and extends from the shielding means adjacent to but spaced apart from the antenna.
32. A radio receiver as claimed in Claim 31 in which the ground referencing means is of electrically conductive sheet material.
33. A radio receiver as claimed in Claim 31 or 32 in which the ground referencing means comprises a ground reference panel extending from the shielding means. 20
34. A radio receiver as claimed in Claim 33 in which the ground reference panel extends parallel to the printed circuit board on which the antenna is printed.
35. A radio receiver as claimed in any of Claims 31 to 34 in which the ground referencing means is of area at least equal to the area of the printed circuit board taken up by the antenna.
36. A radio receiver as claimed in Claim 35 in which the ground referencing means is of area greater than the area of the printed circuit board taken up by the antenna.
37. A radio receiver as claimed in any of Claims 31 to 36 in which the spacing between the ground referencing means and the antenna lies in the range of 10mm to 30mm.
38. A radio receiver as claimed in Claim 37 in which the spacing between the ground referencing means and the antenna lies in the range of 12mm to 20mm.
39. A radio receiver as claimed in Claim 38 in which the spacing between the ground referencing means and the antenna is approximately 15mm.
40. A radio receiver as claimed in any preceding claim in which the radio receiver is adapted for mounting in a vehicle.
41. A radio receiver as claimed in any preceding claim in which the radio receiver is adapted for use in conjunction with a central electronic control unit of a security system of a motor vehicle.
42. A radio receiver substantially as described herein with reference to and as illustrated in
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IE1999/1114A IE83339B1 (en) | 1999-12-17 | A radio receiver |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IEIRELAND22/12/1998S1998/1093 | |||
IE981093 | 1998-12-22 | ||
IE990724 | 1999-08-25 | ||
IE1999/1114A IE83339B1 (en) | 1999-12-17 | A radio receiver |
Publications (2)
Publication Number | Publication Date |
---|---|
IE991114A1 IE991114A1 (en) | 2000-09-06 |
IE83339B1 true IE83339B1 (en) | 2004-03-10 |
Family
ID=
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