Transceiver with closed loop control of antenna tuning and power level

• US 7,469,129 B2
• Filed: 12/19/2005
• Issued: 12/23/2008
• Est. Priority Date: 06/07/1999
• Status: Expired due to Term

• Current Assignee: Gentex Corporation
• Original Assignee: Johnson Controls Technology Company (Johnson Controls International plc)
• Inventors: Blaker, David, Duckworth, Paul, Cardwell, Matthew, Honeck, Brian
• Primary Examiner(s): Jackson; Blane J.
• Application Number:
  US11/311,007
• Publication Number:
  US 20060234670A1
• Time in Patent Office: 1,100 Days
• Field of Search: 455/107, 455/120, 455/121, 455/122, 455/123, 455/124, 455/125, 455/115.1, 455/115.2
• US Class Current: 455/107
• CPC Class Codes: E05F 15/77 using wireless control
• CPC Class Codes: E05Y 2400/664 by radio waves
• CPC Class Codes: E05Y 2900/106 for garages
• CPC Class Codes: G07C 2009/00349 and the lock having only one limited data transmission range
• CPC Class Codes: G07C 2009/00928 for garage doors
• CPC Class Codes: G07C 9/00309 operated with bidirectional data transmission between data carrier and locks
• CPC Class Codes: G07C 9/00857 where the code of the data carrier can be programmed
• CPC Class Codes: G08C 17/02 using a radio link
• CPC Class Codes: G08C 19/28 using pulse code
• CPC Class Codes: G08C 2201/20 Binding and programming of remote control devices

Abstract

A trainable transceiver for learning and transmitting an activation signal that includes an RF carrier frequency modulated with a code for remotely actuating a device, such as a garage door opener. The trainable transceiver preferably includes a controller, a signal generator, and a dynamically tunable antenna having a variable impedance that may be selectively controlled in accordance with a detector circuit signal. The detector circuit provides a measurement of the transmission power and is also used to vary the applied transmission power of the transceiver in response to operating and environmental parameters.

Claims

1. A method of transmitting a device activation signal for remotely actuating a device, the device activation signal having an RF carrier frequency and a power level, comprising the steps of:

providing a transmission antenna assembly having a tunable impedance;

generating the RF carrier frequency;

generating an antenna assembly tuning signal for controlling the antenna assembly impedance;

transmitting the device activation signal at the RF carrier frequency;

detecting the device activation signal power level; and

adjusting the antenna assembly tuning signal in response to the detected activation signal power level;

determining a target detector voltage based on a stored starting point transmission power value associated with stored characteristics of the device activation signal; and

comparing the detected activation signal power level to the target detector voltage;

wherein adjusting the antenna assembly tuning signal in response to the detected activation signal comprises adjusting the antenna assembly tuning signal such that the antenna assembly tuning signal is calculated to result in a detector voltage approximately corresponding to the target detector voltage.

2. The method of claim 1, further comprising the steps of:

receiving a first signal from an original transmitter associated with the device;

determining characteristics of the first signal; and

storing the determined characteristics as characteristics for the device activation signal, wherein the characteristics include the RF carrier frequency.

3. The method of claim 1, wherein the step of generating the RF carrier frequency farther comprises the steps of:

generating a tune level signal for controlling the RF carrier frequency;

generating the RF carrier frequency in response to the tune level signal;

sensing the RF carrier frequency; and

adjusting the tune level signal in response to the sensed RF carrier frequency.

4. A transmitter for transmitting a device activation signal, the device activation signal for remotely actuating a remote device, the device activation signal having an RF carrier frequency and a power level, the transmitter comprising:

a signal generator configured to generate the device activation signal at the RF carrier frequency and to generate one or more test signals at the RF carrier frequency;

a transmission antenna assembly coupled to the signal generator circuit and configured to transmit signals generated by the signal generator at the RF carrier frequency;

controller circuitry coupled to the signal generator and configured to cause the signal generator to generate the device activation signal and to generate the one or more test signals; and

a detector circuit configured to detect a power level of the one or more test signals and to provide indicia of the detected power level to the controller;

wherein the controller circuitry is configured to use the indicia to tune the transmission antenna assembly before causing the signal generator to generate the device activation signal, the controller circuitry configured to use the detector circuit during transmission of the device activation signal to tune the transmission antenna assembly over a limited tuning range while causing the device activation signal to be generated using a modulation scheme configured to remotely actuating the device.

5. The transmitter of claim 4, wherein the transmission antenna assembly has an impedance being tunable in response to a tuning signal received from the controller circuitry, and wherein the controller circuitry tunes the transmission antenna assembly by changing the tuning signal that adjusts the impedance of the transmission antenna assembly.

6. The transmitter of claim 5, wherein the controller circuitry is configured to apply a limited range of tuning signals to the transmission antenna assembly to provide the tuning of the transmission antenna assembly over the limited tuning range, the limited range of tuning signals selected to result in a detected device activation signal power level near the tuning provided by the test signals.

7. The transmitter of claim 4, further comprising:

a gain circuit coupled between the signal generator and the transmission antenna assembly, the gain circuit configured to adjust the power level of the device activation signal provided from the signal generator to the transmission antenna assembly, the gain circuit being responsive to a gain signal provided by the controller, wherein the controller circuitry'"'"'s tuning of the transmission antenna assembly comprises changing the gain signal provided to the gain circuit in response to the indicia of the detected power level.

8. The transmitter of claim 7, wherein the controller circuitry is further configured to retrieve a stored a starting point transmission power value from which a target detector voltage is determined, and wherein the controller circuitry is further configured to generate the gain signal in response to the target detector voltage and the indicia of the detected power level, wherein the indicia is a voltage.

9. The transmitter of claim 4, further comprising:

a receiving antenna configured to receive an activation signal of a remote transmitter, and

wherein the controller circuitry farther includes a training routine module configured to store data corresponding to the remote transmitter'"'"'s activation signal such that the device activation signal corresponds to the activation signal of the remote transmitter.

10. The transmitter of claim 9, wherein the training routine module is configured to store data corresponding to the remote transmitter'"'"'s activation signal such that the RF carrier frequency of the device activation signal and the RF carrier frequency of the one or more test signal corresponds to the RF carrier frequency of the activation signal of the remote transmitter.

11. The transmitter of claim 4, farther comprising a user interface configured to trigger the controller circuitry, and wherein the signal generator includes a voltage controlled oscillator, and wherein the user interface is mounted to a vehicle mirror.

12. The transmitter of claim 11, wherein the transmitter includes memory for storing a plurality of device activation signals and wherein actuation of the user interface causes the transmitter to sequentially transmit the plurality of device activation signals.

13. The transmitter of claim 4, wherein the transmitter is a trainable transmitter having circuitry for determining the device activation signal based on signals received from an original portable transmitter associated with the remote device.

14. A method for transmitting a device activation signal using a transmitter, the device activation signal for remotely actuating a remote device, the device activation signal having an RF carrier frequency and a power level, the method comprising:

generating the device activation signal at the RF carrier frequency and one or more test signals at the RF carrier frequency using a signal generator;

transmitting signals generated by the signal generator at the RF carrier frequency using a transmission antenna assembly coupled to the signal generator circuit;

causing the signal generator to generate the one or more test signals and to provide the one or more test signals to the transmission antenna assembly for transmission;

detecting a power level of the one or more test signals;

tuning the transmission antenna assembly before the transmission of the device activation signal based on the detected power level of the one or more test signals;

transmitting the device activation signal based on the antenna tuning;

providing fine adjustments to the device activation signal during transmission and during the application of a modulation scheme to the device activation signal;

detecting the results of the fine adjustments; and

tuning the transmission antenna assembly based on the results of the fine adjustments.

15. The method of claim 14, wherein the transmission antenna assembly has an impedance being tunable in response to a tuning signal, and wherein the tuning includes changing the tuning signal that adjusts the impedance of the transmission antenna assembly.

16. The method of claim 14, further comprising:

repeating the tuning and detecting steps based on fine adjustments, and wherein the fine adjustments provided to the device activation signal during transmission are of increased resolution relative to the differences between the one or more test signals applied before the transmission of the device activation signal.

17. The method of claim 14, wherein tuning the transmission antenna assembly comprises changing a gain signal provided to a gain circuit between the signal generator circuit and the transmission antenna assembly in response to the detected power level.

18. The method of claim 17, further comprising:

retrieving a stored a starting point transmission power value;

determining a target detector voltage using the stored starting point transmission power value; and

generating the gain signal in response to the target detector voltage and the detected power level.

19. The method of claim 14, further comprising:

receiving an activation signal from a remote transmitter associated with the remote device; and

storing data corresponding to the remote device'"'"'s activation signal such that the device activation signal corresponds to the activation signal of the remote transmitter.

20. The method of claim 14, wherein the transmitter is a trainable transmitter having circuitry for determining characteristics of the device activation signal based on signals received from an original portable transmitter associated with the remote device.