Temperature-stable FBAR transmitter

1. A method comprising:

calculating a frequency drift associated with an oscillator at a current temperature;

based on the calculation, generating a first signal indicative of temperature compensation data;

generating a second signal indicative of packet data and a modulation scheme;

using the first signal and the second signal to generate a tuning signal; and

using the tuning signal to tune a capacitor array coupled to the oscillator such that (i) the oscillator generates a modulated RF signal indicative of the packet data and (ii) the modulated RF signal has a second frequency drift that is less than a threshold.

2. The method of claim 1 , wherein the oscillator is a Pierce oscillator comprising a thin-film bulk acoustic resonator (FBAR).

3. The method of claim 1 , wherein the modulation scheme is Gaussian Frequency Shift Keying (GFSK).

4. The method of claim 1 , wherein the frequency drift is calculated based on the current temperature, a turnover temperature, and a gain coefficient.

5. The method of claim 4 , wherein generating the second signal indicative of the packet data and the modulation scheme comprises:

generating a serialized data stream based on the packet data;

whitening the serialized data stream;

filtering the whitened data stream using a Gaussian filter; and

multiplying the filtered data stream by a predetermined signal to generate the second signal, wherein the predetermined signal is indicative of a frequency deviation of the modulation scheme.

6. The method of claim 5 , wherein the predetermined signal, the turnover temperature, and the gain coefficient are predetermined using an off-chip two-point calibration process.

7. The method of claim 1 , wherein the modulated RF signal comprises advertising packets.

8. A broadcasting unit comprising:

an oscillator;

a capacitor array coupled to the oscillator;

a temperature sensor;

a controller comprising a processor programmed to:

calculate a frequency drift associated with the oscillator at a current temperature;

based on the calculation, generate a first signal indicative of temperature compensation data;

generate a second signal indicative of packet data and a modulation scheme;

use the first signal and the second signal to generate a first tuning signal; and

use the first tuning signal to tune the capacitor array such that (i) the oscillator generates a modulated RF signal indicative of the packet data and (ii) the modulated RF signal has a second frequency drift that is less than a threshold.

9. The broadcasting unit of claim 8 , wherein the oscillator is a Pierce oscillator comprising a thin-film bulk acoustic resonator (FBAR).

10. The broadcasting unit of claim 8 , wherein the modulation scheme is Gaussian Frequency Shift Keying (GFSK).

11. The method of claim 8 , wherein the frequency drift is calculated based on the current temperature, a turnover temperature, and a gain coefficient.

12. The broadcasting unit of claim 11 , wherein generating the second signal indicative of the packet data and the modulation scheme comprises the controller configured to:

generate a serialized data stream based on the packet data;

whiten the serialized data stream;

filter the whitened data stream using a Gaussian filter; and

multiply the filtered data stream by a predetermined signal to generate the second signal, wherein the predetermined signal is indicative of a frequency deviation of the modulation scheme.

13. The broadcasting unit of claim 12 , wherein the predetermined signal, the turnover temperature, and the gain coefficient are predetermined using an off-chip two-point calibration process.

14. The broadcasting unit of claim 8 , wherein the modulated RF signal comprises advertising packets.

15. A system comprising:

a sensor;

a transceiver coupled to the sensor, the transceiver comprising:

an oscillator comprising a thin-film bulk acoustic resonator (FBAR);

a capacitor array coupled to the oscillator;

a temperature sensor; and

an antenna;

a controller comprising a processor programmed to:

calculate a frequency drift associated with the oscillator at a current temperature;

based on the calculation, generate a first signal indicative of temperature compensation data;

generate a second signal indicative of packet data and a modulation scheme;

use the first signal and the second signal to generate a tuning signal; and

use the tuning signal to tune the capacitor array such that (i) the oscillator generates a modulated RF signal indicative of the packet data and (ii) the modulated RF signal has a second frequency drift that is less than a threshold.

16. The system of claim 15 , wherein the oscillator is a Pierce oscillator comprising a thin-film bulk acoustic resonator (FBAR).

17. The system of claim 15 , wherein the modulation scheme is Gaussian Frequency Shift Keying (GFSK).

18. The system of claim 15 , wherein the frequency drift is calculated based on the current temperature, a turnover temperature, and a gain coefficient.

19. The system of claim 18 , wherein generating the second signal indicative of the packet data and the modulation scheme comprises the controller configured to:

generate a serialized data stream based on the packet data;

whiten the serialized data stream;

filter the whitened data stream using a Gaussian filter; and

multiply the filtered data stream by a predetermined signal to generate the second signal, wherein the predetermined signal is indicative of a frequency deviation of the modulation scheme.

20. The system of claim 15 , wherein the packet data is based on an output of the sensor.