# US 9,038,459 B1 · Frequency locking of resonators for improved temperature control of gyroscopes

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 9,038,459 B1
- Document ID: US9038459B1
- Status: Granted
- Kind: B1
- Application number: 13/405,658
- Filed: 2012-02-27
- Granted: 2015-05-26
- Earliest claimed: 2009-12-14
- Assignees: HRL Laboratories, LLC
- Applicants: Randall L. Kubena
- Inventors: Randall L. Kubena
- Web page: https://patentgrep.com/patent/US9038459B1

## CPC

- G01C 19/56: Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces
- G01C 19/5783: Mountings or housings not specific to any of the devices covered by groups G01C19/5607 - G01C19/5719
- G01C: MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY (measuring liquid level G01F; radio navigation, determining distance or velocity by use of propagation effects, e.g. Doppler effects, propagation time, of radio waves, analogous arrangements using other waves G01S)

## Abstract

A precision gyroscope includes a gyroscope, means for receiving an external clock reference, and circuitry coupled to the means for receiving the external clock reference and adapted for stabilizing a temperature and a frequency of the gyroscope.

## Claims

### Claim 1

A precision gyroscope comprising:
a gyroscope, wherein the gyroscope has a frequency;
a clock reference, wherein the clock reference has a frequency; and
circuitry coupled to the clock reference and to the gyroscope, the circuitry configured for stabilizing a temperature and the frequency of the gyroscope;
wherein the frequency of the clock reference is a simple multiple greater than 1 of the frequency of the gyroscope.

### Claim 2 (depends on 1)

The precision gyroscope of claim 1:
wherein the gyroscope and the circuitry are in a first housing or on a semiconductor substrate; and
wherein the semiconductor substrate comprises silicon (Si), silicon germanium (SiGe), gallium arsenide (GaAs), or indium phosphide (InP).

### Claim 3 (depends on 1)

The precision gyroscope of claim 1 wherein the gyroscope and the clock reference share a common temperature controlled housing, or wherein the gyroscope and the clock reference are in separate temperature controlled housings.

### Claim 4 (depends on 1)

The precision gyroscope of claim 1 wherein the gyroscope is a vibrating mode gyroscope.

### Claim 5 (depends on 1)

The precision gyroscope of claim 1 wherein the gyroscope is a disk resonator gyroscope.

### Claim 6 (depends on 1)

The precision gyroscope of claim 1 wherein the circuitry further comprises a feedback loop coupled to the gyroscope and the clock reference for stabilizing the temperature and frequency of the gyroscope.

### Claim 7 (depends on 6)

The precision gyroscope of claim 6 wherein the feedback loop comprises a phase-locked loop.

### Claim 8 (depends on 6)

The precision gyroscope of claim 6 wherein the feedback loop is coupled to a frequency controller to electronically bias a voltage in the gyroscope.

### Claim 9 (depends on 6)

The precision gyroscope of claim 6 wherein the feedback loop is coupled to a heater for controlling a temperature of the gyroscope.

### Claim 10 (depends on 9)

The precision gyroscope of claim 9:
wherein the heater is mounted on a substrate on which the gyroscope is mounted; or
wherein the heater is mounted on a cap enclosing the gyroscope on the substrate.

### Claim 11 (depends on 6)

The precision gyroscope of claim 6:
wherein the gyroscope and the clock reference are in separate temperature controlled housings;
wherein the feedback loop is coupled to a first heater for controlling a temperature of the gyroscope; and
wherein the feedback loop is coupled to a second heater for controlling a temperature of the clock reference.

### Claim 12 (depends on 1)

The precision gyroscope of claim 1:
wherein the clock reference comprises a quartz resonator clock; and
further comprising:
a thermistor coupled to the quartz resonator clock for stabilizing a frequency of the quartz resonator clock.

### Claim 13 (depends on 12)

The precision gyroscope of claim 12 wherein the quartz resonator clock comprises an SC-cut crystal resonator.

### Claim 14 (depends on 1)

The precision gyroscope of claim 1:
wherein the clock reference comprises an atomic clock.

### Claim 15 (depends on 1)

The precision gyroscope of claim 1 further comprising:
an electronic circuit;
wherein the clock reference is a timing source for the electronic circuit.

### Claim 16 (depends on 1)

The precision gyroscope of claim 1 further comprising:
a global positioning system; and
wherein the clock reference is a timing source for the global positioning system.

### Claim 17 (depends on 1)

The precision gyroscope of claim 1:
wherein the gyroscope and the circuitry are in a first housing or on a semiconductor substrate; and
wherein the clock reference is in a second housing.

### Claim 18 (depends on 1)

The precision gyroscope of claim 1 wherein the circuitry comprises:
a divider connected to the clock reference, the divider having an output that has a divided frequency of the frequency of the clock reference; and
a phase lock loop having a first input connected to the output of the divider and a second input connected to the frequency of the gyroscope, and having a phase lock loop output configured for stabilizing a temperature and the frequency of the gyroscope.

### Claim 19 (depends on 18)

The precision gyroscope of claim 18:
wherein the phase lock loop output is coupled to a frequency controller for controlling the frequency of the gyroscope; and
wherein the phase lock loop output is coupled to a heater for controlling a temperature of the gyroscope.

### Claim 20

A precision gyroscope comprising:
a gyroscope, wherein the gyroscope has a frequency;
an external clock reference, wherein the external clock reference has a frequency; and
circuitry coupled to the external clock reference and to the gyroscope, the circuitry configured for stabilizing a temperature and a frequency of the gyroscope;
wherein the frequency of the external clock reference is a simple multiple greater than 1 of the frequency of the gyroscope.

### Claim 21 (depends on 20)

The precision gyroscope of claim 20 wherein the gyroscope is a disk resonator gyroscope.

### Claim 22 (depends on 20)

The precision gyroscope of claim 20 the circuitry comprises:
a feedback loop coupled to the gyroscope and the external clock reference for stabilizing the temperature and frequency of the gyroscope; and
wherein the feedback loop comprises a phase-locked loop.

### Claim 23 (depends on 20)

The precision gyroscope of claim 20 wherein the circuitry comprises:
a divider connected to the external clock reference, the divider having an output that has a divided frequency of the frequency of the external clock reference; and
a phase lock loop having a first input connected to the output of the divider and a second input connected to the frequency of the gyroscope, and having a phase lock loop output configured for stabilizing a temperature and the frequency of the gyroscope.

### Claim 24 (depends on 23)

The precision gyroscope of claim 23:
wherein the phase lock loop output is coupled to a frequency controller for controlling the frequency of the gyroscope; and
wherein the phase lock loop output is coupled to a heater for controlling a temperature of the gyroscope.