SYNTHESIZER AND RECEPTION DEVICE USING THE SAME

• US 20100315138A1
• Filed: 02/10/2009
• Published: 12/16/2010
• Est. Priority Date: 02/12/2008
• Status: Active Grant

• Current Assignee: Mosaid Technologies Incorporated (MOSAID Technologies Inc. (f/k/a Conversant Intellectual Property Management))
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Tsukio, Yasunobu, Fukushima, Susumu, Namba, Akihiko
• Granted Patent: US 8,384,449 B2
• Time in Patent Office: Days
• US Class Current: 327/157
• CPC Class Codes: H03L 1/026 by using a memory for digitally storing correction values H03L1/025 takes precedence
• CPC Class Codes: H03L 1/027 by using frequency conversion means which is variable with temperature, e.g. mixer, frequency divider, pulse add/substract logic circuit H03L1/023, H03L1/026 take precedence
• CPC Class Codes: H03L 7/197 a time difference being used for locking the loop, the counter counting between numbers which are variable in time or the frequency divider dividing by a factor variable in time, e.g. for obtaining fractional frequency division H03L7/1806 takes precedence
• CPC Class Codes: H03L 7/1976 using a phase accumulator for controlling the counter or frequency divider

Abstract

A synthesizer of the present invention includes a synthesizer section that generates an oscillation signal based on a reference oscillation signal output from a MEMS resonator and inputs the oscillation signal to a frequency converter; and a control section that adjusts a frequency of the oscillation signal output from the synthesizer section. In frequency adjustment by the control section, when a frequency adjustment unit of the synthesizer section is defined as predetermined value F in which quality of an output signal from the frequency converter is a quality limit threshold value, frequency adjustment unit Δfcont of the synthesizer section is within predetermined value F.

Claims

1. A synthesizer comprising:

a synthesizer section for generating an oscillation signal based on a reference oscillation signal output from a reference oscillator including a micro-electro-mechanical system (MEMS) resonator, and inputting the oscillation signal to a frequency converter; and

a control section for adjusting a frequency of the oscillation signal output from the synthesizer section,

wherein in frequency adjustment by the control section, when a frequency adjustment unit of the synthesizer section is defined as predetermined value F in which quality of an output signal from the frequency converter shows a quality limit threshold value, frequency adjustment unit Δ

fcont of the synthesizer section is within predetermined value F.

2. The synthesizer of claim 1,

wherein the quality limit threshold value is an error rate limit threshold value.

3. The synthesizer of claim 2,

wherein the error rate limit threshold value is 3×

10̂

−

3.

4. The synthesizer of claim 1,

wherein the synthesizer is installed in a reception device for receiving a time division signal, and

the control section makes the frequency adjustment unit of the synthesizer section larger than the predetermined value F during a period of time in which the reception device does not receive a desired signal.

5. The synthesizer of claim 1,

wherein the synthesizer is installed in a reception device for receiving a signal including a guard interval signal, and

the control section makes the frequency adjustment unit of the synthesizer section larger than the predetermined value F during a period of time in which the reception device receives the guard interval signal.

6. The synthesizer of claim 1,

wherein when a frequency fluctuation of an oscillation signal is out of a permissible range, the frequency adjustment unit of the synthesizer section is made to be larger than the predetermined value F.

7. The synthesizer of claim 1,

further comprising a temperature detection section for detecting a temperature,

wherein the control section adjusts a frequency of the oscillation signal based on a detection result by the temperature detection section.

8. The synthesizer of claim 1,

further comprising a frequency difference detection section connected to an output side of the frequency converter,

wherein the control section adjusts a frequency of the oscillation signal based on a detection result by the frequency difference detection section.

9. The synthesizer of claim 8,

wherein the control section carries out an amount of frequency adjustment derived from the detection result by a plurality of frequency adjustments.

10. The synthesizer of claim 1,

wherein the predetermined value F is 160 Hz.

11. A reception device comprising a synthesizer of claim 1.

12. A synthesizer for outputting an oscillation signal,

wherein a correction amount of an oscillation frequency of the synthesizer is determined based on a use state of an electronic device using the synthesizer.

13. The synthesizer of claim 12, comprising:

a comparator for receiving a reference oscillation signal;

an oscillator for outputting an oscillation signal based on an output signal of the comparator; and

a frequency divider for frequency-dividing the output signal of the oscillator based on a control signal from a control section,

wherein the comparator compares an output signal from the frequency divider with an output signal from a reference oscillator, and outputs a signal indicating a comparison result to the oscillator, and

a value of a frequency division ratio of the frequency divider is determined based on the use state of the electronic device using the synthesizer.

14. The synthesizer of claim 13,

wherein a timing is previously determined, at which the frequency division ratio of the frequency divider is changed to the value of the frequency division ratio that is determined according to the use state of the electronic device.

15. A reception device comprising:

a synthesizer of claim 12, and

a signal processing section connected to an output side of the synthesizer.

16. A synthesizer comprising:

a comparator for receiving a reference oscillation signal output from a reference oscillator;

a voltage controlled oscillator for outputting an oscillation signal based on an output signal of the comparator; and

a frequency divider for frequency-dividing an output signal of the voltage controlled oscillator based on a control signal from a control section;

wherein the comparator compares an output signal from the frequency divider with an output signal from the reference oscillator, and outputs a signal indicating a comparison result to the voltage controlled oscillator, and

the control section changes a frequency division ratio of the frequency divider at a nonuniform time interval based on a temperature signal of a temperature detection section for detecting a temperature.

17. The synthesizer of claim 16,

wherein the control section changes the frequency division ratio of the frequency divider based on the temperature signal of the temperature detection section for detecting a temperature at an aperiodic time interval.

18. The synthesizer of claim 16,

wherein the temperature signal from the temperature detection section is transmitted to the control section at time interval T1,

when a control signal is newly transmitted from the control section at t2 that is a time after a lapse of T2=n×

T1 (n is an integer of 2 or more) from t1 that is any time at which a control signal is transmitted from the control section in a previous time, the temperature signal from the temperature detection section is transmitted to the control section at time interval T3=m×

T1 (m is a numeric value of m>

1) at t2 or later, and

when a control signal is newly transmitted from the control section at t2 that is a time after a lapse of T2=T1 from t1 that is any time at which the control signal is transmitted from the control section in a previous time, the temperature signal from the temperature detection section is transmitted to the control section at time interval T4=k×

T1 (k is a decimal fraction of 0<

k<

1).

19. A reception device comprising:

a synthesizer of claim 16, and

a mixer for converting a frequency of a received signal based on the oscillation signal from the synthesizer.

20. The reception device of claim 19,

wherein the temperature detection section detects temperature information by detecting a frequency difference between the oscillation signal from the synthesizer and the received signal.