Transmitter tolerant to crystal variations

• US 6,677,862 B1
• Filed: 05/17/1999
• Issued: 01/13/2004
• Est. Priority Date: 05/17/1999
• Status: Expired due to Term

• Current Assignee: Landis+Gyr Innovations Incorporated (Landis+Gyr Group AG)
• Original Assignee: SchlumbergerSema Inc (Schlumberger NV)
• Inventors: Houlihane, Thomas Sean, Summers, Andrew Gordon
• Primary Examiner(s): EDWARDS JR, TIMOTHY
• Application Number:
  US09/313,050
• Time in Patent Office: 1,702 Days
• Field of Search: 340/870.02, 340/870.03, 340/870.17, 375/295, 375/329, 375/326, 375/327, 375/306, 375/309, 455/91
• US Class Current: 340/870.03
• CPC Class Codes: H04B 1/0025 using a sampling rate lower than twice the highest frequency component of the sampled signal for demodulation of angle-modulated signals H03D3/006
• CPC Class Codes: H04B 1/28 the receiver comprising at least one semiconductor device having three or more electrodes
• CPC Class Codes: H04B 1/40 Circuits
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 5/06 the signals being represented by different frequencies combined with time-division multiplexing H04L5/26
• CPC Class Codes: H04Q 2209/60 for transmitting utility meters data, i.e. transmission of data from the reader of the utility meter
• CPC Class Codes: H04Q 9/12 using combinations of frequencies

Abstract

A transmitter to transmit data from an end-point includes a reference oscillator; a low pass filter coupled to the reference oscillator; a modulation filter to provide an over-sampled modulated signal; a synthesizer coupled to the low pass filter and the modulation filter; and a sine wave generator coupled to the synthesizer.

Claims

1. A transmitter to transmit data from an end-point, comprising:

a reference oscillator;

a low pass filter coupled to the reference oscillator;

a modulation filter to provide an over-sampled modulated signal;

a synthesizer coupled to the low pass filter and the modulation filter; and

a sine wave generator coupled to the synthesizer.

2. The transmitter of claim 1, further comprising a harmonic filter coupled to the sine wave generator.

3. The transmitter of claim 1, further comprising an amplifier coupled to the sine wave generator.

4. The transmitter of claim 1, wherein the low pass filter further comprises:

a resistor; and

a capacitor coupled to the resistor to provide a resistor capacitor time constant.

5. The transmitter of claim 1, further comprising a loop filter positioned between the synthesizer and the sine wave generator.

6. The transmitter of claim 1, further comprising an antenna coupled to the sine wave generator.

7. The transmitter of claim 6, wherein the antenna is a loop antenna.

8. The transmitter of claim 6, wherein the antenna is a printed circuit board antenna strip.

9. The transmitter of claim 8, further comprising a circuit trace adapted to receive radio frequency (RF) components, the circuit trace being interior to the printed circuit board antenna strip.

10. The transmitter of claim 8, further comprising an impedance matching strip coupled to the antenna.

11. A remote data collection system for collecting usage data from an endpoint, comprising:

a monitoring module coupled to the endpoint, the monitoring module having a wireless transmitter to transmit the usage data, the wireless transmitter including;

a reference oscillator;

a low pass filter coupled to the reference oscillator;

a modulation filter to provide an over-sampled modulated signal;

a synthesizer coupled to the low pass filter and the modulation filter;

a sine wave generator coupled to the synthesizer; and

an antenna coupled to the sine wave generator; and

a data communication network coupled to the transmitter to communicate the usage data from the endpoint to a database.

12. The remote data collection system of claim 11, further comprising a harmonic filter coupled to the sine wave generator.

13. The remote data collection system of claim 11, further comprising an amplifier coupled to the sine wave generator.

14. The remote data collection system of claim 11, wherein the low pass filter further comprises:

a resistor; and

a capacitor coupled to the resistor to provide a resistor capacitor time constant.

15. The remote data collection system of claim 11, further comprising a loop filter positioned between the synthesizer and the sine wave generator.

16. The remote data collection system of claim 11, further comprising an antenna coupled to the sine wave generator.

17. The remote data collection system of claim 16, wherein the antenna is a loop antenna.

18. The remote data collection system of claim 16, wherein the antenna is a printed circuit board antenna strip.

19. The remote data collection system of claim 18, further comprising a circuit trace adapted to receive radio frequency (RF) components, the circuit trace being interior to the printed circuit board antenna strip.

20. The remote data collection system of claim 18, further comprising an impedance matching strip coupled to the antenna.