Reference oscillator frequency stabilization

• US 7,248,128 B2
• Filed: 02/02/2005
• Issued: 07/24/2007
• Est. Priority Date: 02/03/2004
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Mattila, Tomi, Oja, Aarne, Sepp, Heikki, Jaakkola, Olli
• Primary Examiner(s): Pascal; Robert
• Assistant Examiner(s): Gannon; Levi
• Application Number:
  US11/050,142
• Publication Number:
  US 20050184822A1
• Time in Patent Office: 902 Days
• Field of Search: 331/49, 331/107.P, 331/116.M, 331/116.R, 331/141, 331/154, 331/175
• US Class Current: 331/175
• CPC Class Codes: H03H 2009/02496 Horizontal, i.e. parallel to the substrate plane
• CPC Class Codes: H03H 2009/02503 Breath-like, e.g. Lam? mode, wine-glass mode
• CPC Class Codes: H03H 9/02244 of microelectro-mechanical resonators
• CPC Class Codes: H03H 9/38 with adjustable delay time H03H9/40, H03H9/42 take precedence
• CPC Class Codes: H03L 1/022 by indirect stabilisation, i.e. by generating an electrical correction signal which is a function of the temperature H03L1/021 takes precedence
• CPC Class Codes: H03L 7/00 Automatic control of frequency or phase; Synchronisation
• CPC Class Codes: H03L 7/06 using a reference signal applied to a frequency- or phase-locked loop
• CPC Class Codes: H03L 7/099 concerning mainly the controlled oscillator of the loop

Abstract

Method for stabilizing the frequency of a MEMS (Micro Electro Mechanical Systems) reference oscillator, and a MEMS reference oscillator, wherein the method comprises following steps: using two or more MEMS components, wherein each MEMS component is characterized by a set of properties, and selectively combining the desired properties from the MEMS components.

Claims

1. MEMS (Micro Electro Mechanical Systems) reference oscillator with stabilized frequency, characterised in that the oscillator comprises:

two or more MEMS components, wherein each MEMS component is characterized by a set of properties, and

a combiner for selective combination of the desired properties from the MEMS components,

characterised in that at least one of the components is a micromechanical bulk acoustic mode silicon resonator with a square plate and electrodes for capacitive coupling arranged on all sides of the plate, wherein the vibration mode is characterised as a 2-D plate expansion that preserves the original square shape.

2. MEMS reference oscillator according to claim 1, characterised in that the type of at least one MEMS component is different from the types of the other MEMS components.

3. MEMS reference oscillator according to claim 1, characterised in that the components are identical but their control parameters, including bias voltage, are different.

4. MEMS reference oscillator according to claim 1, characterised in that the oscillator utilizes a stable frequency reference based on an bulk acoustic mode oscillator and a frequency meter operation based on comparing the frequency created by the bulk acoustic wave oscillator with the output frequency of the oscillator.

5. MEMS (Micro Electro Mechanical Systems) reference oscillator with stabilized frequency, characterised in that the oscillator comprises:

two or more MEMS components, wherein each MEMS component is characterized by a set of properties, and

a combiner for selective combination of the desired properties from the MEMS components,

characterised in that the oscillator utilizes a stable frequency reference obtained by measuring the phase difference of propagating bulk acoustical wave in a micromachined sound-wave guide at fixed positions.

6. MEMS (Micro Electro Mechanical Systems) reference oscillator with stabilized frequency, characterised in that the oscillator comprises:

two or more MEMS components, wherein each MEMS component is characterized by a set of properties, and

a combiner for selective combination of the desired properties from the MEMS components,

characterised in that the oscillator utilizes a frequency meter based on stable capacitors and stable micromachined thin-film resistors that are used to create the Wien oscillator topology.

7. MEMS (Micro Electra Mechanical Systems) reference oscillator with stabilized frequency, characterised in that the oscillator comprises:

two or more MEMS components, wherein each MEMS component is characterized by a set of properties, and

a combiner for selective combination of the desired properties from the MEMS components,

characterised in that a capacitor-resistor network, that is part of the Wien oscillator circuit, is used as a frequency meter in which the capacitors and resistors form a bridge circuit the balance of which depends on the frequency of the incoming frequency.