Spread-spectrum radio utilizing MEMS components
View Patent ↗A spread-spectrum radio, such as a frequency-hopping spread-spectrum radio or a direct-sequence spread-spectrum radio, includes a transmitter that utilizes microelectromechanical systems (MEMS) based oscillation system to generate a spread-spectrum signal and/or a receiver that utilizes a MEMS-based frequency selection system to receive a spread-spectrum signal. In an embodiment, the MEMS-based oscillation system and the MEMS-based frequency selection system utilize MEMS resonators such as thin film bulk acoustic resonators (FBARs) that are fabricated in high density on a single substrate.
1. A spread-spectrum transmitter comprising: microelectromechanical systems (MEMS) based oscillation system comprising at least one MEMS resonator and being configured to generate signals at different frequencies; and the MEMS based oscillation system further comprising a controllable switch configured to select one signal at a time within the MEMS-based oscillation system in response to a spread-spectrum code, the output from the controllable switch being a spread-spectrum signal.
2. The spread-spectrum transmitter of claim 1 further comprising a modulator configured to receive the spread-spectrum signal from the MEMS-based oscillation system and to modulate the spread-spectrum signal in response to an information signal.
3. The spread-spectrum transmitter of claim 1 wherein the MEMS-based oscillation system comprises multiple MEMS resonators configured to resonate at different frequencies.
4. The spread-spectrum transmitter of claim 1 wherein the MEMS-based oscillation system comprises multiple selectable impedance elements that exhibit different impedances.
5. The spread-spectrum transmitter of claim 1 wherein the MEMS resonator comprises a thin film bulk acoustic resonator (FBAR).
6. The spread-spectrum transmitter of claim 1 wherein the MEMS-based oscillation system further comprises a signal amplifier electrically connected to the MEMS resonator.
7. The spread-spectrum transmitter of claim 6 wherein the amplifier is fabricated on a first substrate and the MEMS resonator is fabricated on a second substrate.
8. The spread-spectrum transmitter of claim 7 wherein the first substrate is flip-chip bonded to the second substrate.
9. The spread-spectrum transmitter of claim 1 wherein the spread-spectrum code is one of a frequency-hopping spread-spectrum code or a direct-sequence spread-spectrum code.
10. The spread-spectrum transmitter of claim 1 wherein the controllable switch selects signals in a pseudo-random order.
11. A spread-spectrum receiver comprising: an antenna; microelectromechanical systems (MEMS) based frequency selection system comprising at least one MEMS resonator and configured to pass a signal at a selected frequency, wherein the selected frequency is included in a predetermined set of frequencies; and the MEMS-based frequency selection system further comprising a controllable switch configured to select one output at a time within the MEMS-based frequency selection system in response to a spread spectrum code, the output from the MEMS-based frequency selection system being a spread-spread-spectrum signal.
12. The spread-spectrum receiver of claim 11 further comprising a demodulator configured to receive the spread-spectrum signal from the MEMS-based frequency selection system and to extract an information signal therefrom.
13. The spread-spectrum receiver of claim 11 wherein the MEMS-based frequency selection system comprises multiple MEMS resonators configured to resonate at respective ones of the predetermined set of frequencies.
14. The spread-spectrum receiver of claim 11 wherein the MEMS-based frequency selection system comprises multiple MEMS resonators connected to output local oscillator signals at frequencies that correspond to the frequencies of the respective MEMS resonators.
15. The spread-spectrum receiver of claim 11 wherein the MEMS-based frequency selection system comprises multiple selectable impedance elements that exhibit different impedances.
16. The spread-spectrum receiver of claim 11 wherein the MEMS resonator comprises a thin film bulk resonator (FBAR).
17. The frequency-hopping spread-spectrum receiver of claim 16 comprising multiple FBARS wherein the FBARs are fabricated on the same substrate.
18. A method for transmitting a modulated, spread-spectrum signal by a first radio, the method comprising: generating signals at predetermined frequencies using a microelectromechanical systems (MEMS) based oscillation system that comprises at least one MEMS resonator and is configured to generate signals at different frequencies; and selecting the signals from the MEMS-based oscillation system, one at a time, in response to a spread-spectrum code, thereby forming a spread-spectrum signal.
19. The method according to claim 18 further comprising: modulating the spread-spectrum signal in response to an information signal; and transmitting the modulated spread-spectrum signal.
20. The method according to claim 18 further comprising decoding the spread-spectrum signal at a second radio, the decoding comprising: utilizing at least one MEMS resonator to receive the spread-spectrum signal, wherein receiving the spread-spectrum signal comprises selecting one signal at a time related to the at least one MEMS resonator in response to a second spread-spectrum code; and extracting an information signal from the received spread-spectrum signal.
21. The method according to claim 20 further comprising synchronizing the first and second spread-spectrum codes.