Method and subsystem for processing signals utilizing a plurality of vibrating micromechanical devices

• US 6,917,138 B2
• Filed: 07/24/2003
• Issued: 07/12/2005
• Est. Priority Date: 01/14/1999
• Status: Expired due to Term

• Current Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Original Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Inventors: Nguyen, Clark T. -C.
• Primary Examiner(s): Dougherty, Thomas M.
• Application Number:
  US10/625,993
• Publication Number:
  US 20040095210A1
• Time in Patent Office: 719 Days
• Field of Search: 310/309, 310/311, 333/133, 333/186, 333/197, 333/198
• US Class Current: 310/311
• CPC Class Codes: H01H 2059/0072 with stoppers or protrusions for maintaining a gap, reducing the contact area or for preventing stiction between the movable and the fixed electrode in the attracted position
• CPC Class Codes: H01H 59/0009 making use of micromechanics
• CPC Class Codes: H03H 2009/02511 Vertical, i.e. perpendicular to the substrate plane
• CPC Class Codes: H03H 2009/02519 Torsional
• CPC Class Codes: H03H 2009/02527 Combined
• CPC Class Codes: H03H 3/0078 involving adjustment of the transducing gap
• CPC Class Codes: H03H 9/02409 by application of a DC-bias voltage H03H9/02417 takes precedence
• CPC Class Codes: H03H 9/24 Constructional features of resonators of material which is not piezoelectric, electrostrictive, or magnetostrictive
• CPC Class Codes: H03H 9/2452 Free-free beam resonators
• CPC Class Codes: H03H 9/462 Microelectro-mechanical filters
• CPC Class Codes: H03H 9/465 in combination with other electronic elements
• CPC Class Codes: H03H 9/505 for microelectro-mechanical filters

Abstract

Several MEMS-based methods and architectures which utilize vibrating micromechanical resonators in circuits to implement filtering, mixing, frequency reference and amplifying functions are provided. A method and subsystem are provided for processing RF signals utilizing a plurality of vibrating micromechanical devices typically in the form of an IF mixer-filter and an RF channel selector or an image-reject RF filter. One of the primary benefits of the use of such architectures is a savings in power consumption by trading power for high selectivity (i.e., high Q). Also, such methods and circuits can eliminate the need for a low noise amplifier in a receiver or transceiver subsystem. Consequently, the present invention relies on the use of a large number of micromechanical links in SSI networks to implement signal processing functions with basically zero DC power consumption.

Claims

1. A method for processing signals in an RF subsystem to eliminate the need for a low noise amplifier therein, the method comprising:

providing a plurality of intercoupled micromechanical devices including an input port for receiving signals and an output port; and

vibrating the micromechanical devices to initially pass a desired frequency range of unamplified signals while substantially attenuating signals outside the desired frequency range and then to convert between first and second frequencies and filter the desired frequency range of unamplified signals without the need for the low noise amplifier.

2. The method as claimed in claim 1 wherein the low noise amplifier is an RF low noise amplifier.

9. The method as claimed in claim 1 wherein the first frequency is in an RF range and the second frequency is in an IF range.

3. An RF receiver subsystem which eliminates the need for a low noise amplifier therein, the subsystem comprising:

an image-reject vibrating micromechanical filter including an input port for receiving signals, the filter passing a desired frequency range of the signals while substantially attenuating signals outside the desired frequency range; and

a vibrating micromechanical mixer-filter coupled to the filter having an output port, the mixer-filter being adapted to be coupled to electronics for converting and filtering the desired frequency range of signals without the need for the low noise amplifier.

4. The subsystem as claimed in claim 3 wherein the low noise amplifiers an RF low noise amplifier.

5. The subsystem as claimed in claim 3 wherein the filter is a relatively wide band filter and the mixer-filter is a narrow band mixer-filter.

10. The subsystem as claimed in claim 3 wherein the vibrating micromechanical mixer-filter converts from an RF range to an IF range.

11. The subsystem as claimed in claim 3 wherein the image-reject vibrating micromechanical filter passes unamplified signals within the desired frequency range to the vibrating micromechanical mixer-filter.

6. An RF receiver subsystem which eliminates the need for a low noise amplifier, the subsystem comprising:

a vibrating micromechanical frequency range selector having an input port for receiving signals, the selector passing a desired frequency range of the signals while substantially attenuating signals outside the desired frequency range; and

a vibrating micromechanical mixer-filter coupled to the selector having an output port and being adapted to be connected to electronics for converting and filtering the desired frequency range of signals without the need for the low noise amplifier.

7. The subsystem as claimed in claim 6 wherein the low noise amplifier is an RF low noise amplifier.

12. The subsystem as claimed in claim 6 wherein the vibrating micromechanical mixer-filter converts from an RF range to an IF range.

13. The subsystem as claimed in claim 6 wherein the vibrating micromechanical frequency range selector passes unamplified signals within the desired frequency range to the vibrating micromechanical mixer-filter.

8. An RF transceiver subsystem which substantially reduces the need for RF front-end power, the subsystem comprising:

a vibrating micromechanical frequency range selector having any input port for receiving signals, the selector passing a desired frequency range of the signals while substantially attenuating signals outside the desired frequency range; and

a vibrating micromechanical mixer-filter coupled to the selector having an output port, the mixer-filter being adapted to be connected to electronics for converting and filtering signals wherein the reed for RF front-end power is substantially reduced.

14. The subsystem as claimed in claim 8 wherein the vibrating micromechanical mixer-filter converts between an RF range and an IF range.

15. The subsystem as claimed in claim 8 wherein the vibrating micromechanical frequency range selector passes unamplified signals within the desired frequency range to the vibrating micromechanical mixer-filter.