Antenna for tire monitoring device

• US 5,196,845 A
• Filed: 12/27/1991
• Issued: 03/23/1993
• Est. Priority Date: 10/24/1988
• Status: Expired due to Term

• Current Assignee: Compagnie Generale DES Etablissements Michelin SCA
• Original Assignee: Compagnie Generale DES Etablissements Michelin SCA
• Inventors: Myatt, David
• Primary Examiner(s): Yusko, Donald J.
• Assistant Examiner(s): Horabik, Michael
• Application Number:
  US07/818,441
• Time in Patent Office: 452 Days
• Field of Search: 340/448, 340/870.31, 340/870.33, 340/870.37, 340/442, 340/445, 340/447, 73/146.4, 73/146.5, 343/745, 343/749, 343/750
• US Class Current: 340/870.31
• CPC Class Codes: B60C 23/0427 Near field transmission with inductive or capacitive coupling means
• CPC Class Codes: B60C 23/0428 using passive wheel mounted resonance circuits
• CPC Class Codes: G06K 19/07764 the adhering arrangement making the record carrier attachable to a tire tire temperature or pressur control arrangements, see B60C23/00
• CPC Class Codes: H01Q 1/2241 used in or for vehicle tyres
• CPC Class Codes: H01Q 1/32 Adaptation for use in or on road or rail vehicles
• CPC Class Codes: H01Q 1/3233 particular used as part of a sensor or in a security system, e.g. for automotive radar, navigation systems
• CPC Class Codes: H01Q 7/06 with core of ferromagnetic material H01Q7/02 takes precedence

Abstract

An antenna to be used with transponder type devices. The antenna includes an inductance and a capacitor forming a resonant circuit. To avoid any heating and to have a sufficiently broad passband or operating range, there is in parallel with the inductance, a branch comprising two Zener diodes connected in opposite directions. Any nonlinear damping arrangement having an equivalent effect may be used in the branch.

Claims

1. First antenna integral with a wheel support for a tire monitoring device which transmits by inductive coupling with a second antenna integral with a wheel, said first antenna comprising:

an inductance forming coil;

a capacitance connected to said coil, said capacitance and said coil forming a resonant circuit; and

means to clip the flux passing from said first antenna to said second antenna, so as to introduce a non-linear damping of said resonant circuit whereby said first antenna acquires a combination of a high quality factor and a broad pass band.

2. First antenna according to claim 1, wherein said means to clip comprises a branch connected in parallel with said coil, said branch comprising two Zener diodes connected in series and in opposite directions.

3. First antenna according to claim 1, wherein said means to clip comprises a branch connected in parallel with said capacitance, said branch comprising two Zener diodes connected in series and in opposite directions.

4. First antenna according to claim 1, wherein said means to clip comprises a branch connected in parallel with said coil, said branch comprising a varistor.

5. First antenna according to claim 1, wherein said means to clip comprises a branch connected in parallel with said capacitance, said branch comprising a varistor.

6. First antenna according to claim 1, wherein said means to clip comprises a branch connected in parallel with said coil, said branch comprising a controlled avalanche diode.

7. First antenna according to claim 1, wherein said means to clip comprises a branch connected in parallel with said capacitance, said branch comprising a controlled avalanche diode.

8. First antenna according to claim 1, wherein said means to clip comprises a magnetic circuit comprising a saturatable ferrite.

9. First antenna according to claim 8, wherein said means to clip further comprises a coil for control of the flux circulating in the magnetic circuit of said first antenna.

10. First antenna according to claim 1, wherein said means to clip dissipates energy in said resonant circuit and limits a voltage applied to said coil.

11. First antenna integral with a wheel support device which transmits by capacitive coupling with a second antenna integral with a wheel, said first antenna comprising:

a capacitor plate from which an electric field radiates;

a coil of given inductance;

a capacitor of given capacitance, said capacitance of the capacitor and said inductance forming a resonant circuit; and

means to clip the electric field radiating from the capacitor plate so as to introduce a non-linear damping of said resonant circuit whereby aid first antenna acquires a combination of a high quality factor and a broad pass band.

12. First antenna according to claim 11, wherein said means to clip comprises a branch connected in parallel with the coil, said branch comprising two Zener diodes connected in series and in opposite directions.

13. First antenna according to claim 11, wherein said means to clip comprises a branch connected in parallel with the capacitor, said branch comprising two Zener diodes connected in series and in opposite directions.

14. First antenna according to claim 11, wherein said means to clip comprises a branch connected in parallel with the coil, said branch comprising a varistor.

15. First antenna according to claim 11, wherein said means to clip comprises a branch connected in parallel with the capacitor, said branch comprising a varistor.

16. First antenna according to claim 11, wherein said means to clip comprises a branch connected in parallel with the coil, said branch comprising a controlled avalanche diode.

17. First antenna according to claim 11, wherein said means to clip comprises a branch connected in parallel with the capacitor, said branch comprising a controlled avalanche diode.

18. First antenna according to claim 11, wherein said means to clip dissipates energy in said resonant circuit and limits a voltage applied to said coil.