Radio having a MEMS preselect filter

• US 20060057959A1
• Filed: 09/10/2004
• Published: 03/16/2006
• Est. Priority Date: 09/10/2004
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Vacanti, David C., Jafri, Ijaz H., Bayern, Keith A.
• Granted Patent: US 7,668,505 B2
• Time in Patent Office: Days
• US Class Current: 455/20
• CPC Class Codes: H03H 9/462 Microelectro-mechanical filters

Abstract

The present invention provides systems and methods for pre-filter in a VHF receiver using Micro-Electro-Mechanical Systems (MEMS) filters. The system includes an antenna, and first and second Micro-Electro-Mechanical Systems (MEMS) filters. The first MEMS filter filters a signal received by the antenna based on a first pre-defined bandwidth, and the second MEMS filter filters the signal filtered by the first MEMS filter based on a second bandwidth. The system also includes an analog to digital converter that converts the signal filtered by the second MEMS filter into a digital signal, a down converter that down converts the digital signal produced by the A to D converter, and a digital signal processor that processes the down converted digital signal produced by the down converter. The first and second MEMS filters or the down converter are adjustable based on a received tuning signal.

Claims

1. A system comprising:

an antenna; and

a pre-select filter in signal communication with the antenna, the pre-select filter comprising;

a first Micro-Electro-Mechanical Systems (MEMS) filter; and

a second MEMS filter in signal communication with the first MEMS filter,

wherein the first MEMS filter filters a signal received by the antenna based on a first bandwidth, and the second MEMS filter filters the signal filtered by the first MEMS filter based on a second bandwidth.

2. The system of claim 1, further comprising an analog to digital converter for converting the signal filtered by the second MEMS filter into a digital signal.

3. The system of claim 2, further comprising a down converter for down converting the digital signal produced by the A to D converter.

4. The system of claim 3, further comprising a digital signal processor for processing the down converted digital signal produced by the down converter.

5. The system of claim 4, wherein at least one of the first and second MEMS filters or the down converter are adjustable based on a received tuning signal.

6. The system of the claim 5, wherein the tuning signal includes a tuning voltage.

7. The system of claim 1, wherein the filtered frequencies of the first MEMS filter is offset from the filtered frequencies of the second MEMS filter by a pre-defined amount.

8. The system of claim 7, wherein the offset is between 230-270 khz and the bandwidth of the MEMS filters are between 0.9 MHz and 2.1 MHz.

9. A system comprising:

an antenna; and

a pre-select filter in signal communication with the antenna, the pre-select filter comprising;

a plurality of subfilters configured to filter the received signal, each subfilter comprising;

a first Micro-Electro-Mechanical Systems (MEMS) filter set to filter the received signal at a first bandwidth;

a second MEMS filter configured to filter the signal filtered by the MEMS filter at a second bandwidth that is offset from the first bandwidth; and

a switch coupled to the second MEMS filter, wherein the switch is activated based on the tuning signal received by the pre-select filter.

10. The system of claim 9, wherein each subfilter filters a predefined channel.

11. The system of claim 10, wherein the channel has a bandwidth between 230-270 khz and the bandwidth of the MEMS filters are between 0.9 MHz and 2.1 MHz.

12. The system of claim 9, further comprising an analog to digital converter for converting the signal filtered by the pre-select filter.

13. The system of claim 12, further comprising a down converter for down converting the digital signal produced by the A to D converter.

14. The system of claim 13, further comprising a digital signal processor for processing the down converted digital signal produced by the down converter.

15. The system of claim 14, further comprising a tuning controller for controlling the switches.

16. A method comprising:

receiving a radio signal at an antenna;

generating a first signal by filtering the signal received by the antenna using a first MEMS filter; and

generating a second signal by filtering the first signal using a second MEMS filter.

17. The method of claim 16, further comprising:

converting the second signal into a digital signal;

down converting the digital signal; and

processing the down converted signal at a digital signal processor.

18. The method of claim 16, wherein the first and second MEMS filters are adjustable based on a received tuning signal.

19. The method of the claim 18, wherein the tuning signal includes a tuning voltage.

20. The method of claim 16, wherein the filtered frequencies of the first MEMS filter is offset from the filtered frequencies of the second MEMS filter by a pre-defined amount.

21. The method of claim 20, wherein the offset is between 230-270 khz and the bandwidth of the MEMS filters are between 0.9 MHz and 2.1 MHz.

22. A method comprising:

receiving a radio signal at an antenna;

generating a first signal by filtering the signal received by the antenna using one of a plurality of first MEMS filters; and

generating a second signal by filtering the first signal using one of a plurality of second MEMS filters.

23. The method of claim 22, further comprising:

converting the second signal into a digital signal;

down converting the digital signal; and

processing the down converted signal at a digital signal processor.

24. The method of claim 22, further comprising:

receiving a tuning signal; and

selecting a second signal produced by one of the plurality of second MEMS filters based on the received tuning signal.

25. The method of claim 22, wherein the filtered frequencies of the plurality of first MEMS filter is offset from the filtered frequencies of the plurality of second MEMS filter by a pre-defined amount.

26. The method of claim 25, wherein the offset is between 230-270 khz and the bandwidth of the MEMS filters are between 0.9 MHz and 2.1 MHz.