CN102025320B - Device and method for improving frequency stability of WIFI (wireless fidelity) access point - Google Patents
Device and method for improving frequency stability of WIFI (wireless fidelity) access point Download PDFInfo
- Publication number
- CN102025320B CN102025320B CN 201010558837 CN201010558837A CN102025320B CN 102025320 B CN102025320 B CN 102025320B CN 201010558837 CN201010558837 CN 201010558837 CN 201010558837 A CN201010558837 A CN 201010558837A CN 102025320 B CN102025320 B CN 102025320B
- Authority
- CN
- China
- Prior art keywords
- resistance
- crystal oscillator
- voltage
- access point
- temperature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 238000000034 method Methods 0.000 title claims abstract description 17
- 239000013078 crystal Substances 0.000 claims abstract description 88
- 238000001514 detection method Methods 0.000 claims abstract description 30
- 238000001914 filtration Methods 0.000 claims description 5
- 238000004891 communication Methods 0.000 abstract description 12
- 230000007547 defect Effects 0.000 abstract description 2
- 230000007613 environmental effect Effects 0.000 abstract 2
- 239000003990 capacitor Substances 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 230000002277 temperature effect Effects 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 1
- 230000003044 adaptive effect Effects 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
Images
Landscapes
- Oscillators With Electromechanical Resonators (AREA)
Abstract
The invention relates to the field of WLAN (wireless local area network) wireless access, disclosing a device and a method for improving the frequency stability of a WIFI access point. The device for improving the frequency stability of the WIFI access point is composed of a temperature detection circuit, a voltage compensation circuit and a crystal oscillator, wherein the temperature detection circuit is connected with the voltage compensation circuit connected with the crystal oscillator. The defects of poor accuracy of the crystal temperature of the WLAN access point and weak fixed voltage compensation adaptability is overcome. In the invention, the influence on the communication quality of the WLAN access point by environmental temperature is considered fully, communication quality by improving access point frequency accuracy is improved and the orthogonality of OFDM (Orthogonal Frequency Division Multiplexing) subcarrier is ensured. Meanwhile, frequency accuracy is dynamically adjusted, so that equipment can adapt to environmental temperature variation and ensure the communication reliability of the WLAN access point.
Description
Technical field
The present invention relates to WLAN wireless access field, in particular a kind of apparatus and method that improve WIFI access point frequency stability.
Background technology
WLAN(WLAN Wireless Local Area Networks) the various clocks of access point are to be provided by crystal oscillator, and the precision of crystal oscillator has just determined the precision of all kinds of clocks of WLAN access point, has also determined the accuracy of rf frequency.
Common quartz crystal oscillator is because the impact of ambient temperature, and the frequency of crystal oscillator can be drifted about, and can include the long steady category of crystal in because the variation of crystal temperature effect causes the crystal oscillator frequency drift.If allow the crystal free oscillation, namely do not solve the steady defective of length of crystal, the clock accuracy of WLAN access point will be As time goes on worse and worse.
At present in the IEEE802.11g/n WLAN standard in order to improve data transmit-receive speed, having used OFDM(is orthogonal frequency division multiplexi) technology.In IEEE802.11g, 52 carrier frequency have been used altogether; In IEEE802.11n, 114 carrier frequency have been used altogether, as shown in Figure 1.
Wlan standard is used the spectrum diagram of OFDM technology, is illustrated in figure 2 as sinc function schematic diagram, has only drawn 5 carrier frequency among the figure, and the available sinc function representation of each carrier frequency out.
As can be seen from Figure 1, when drift occured the frequency source crystal frequency, above-mentioned frequency spectrum orthogonality was destroyed, the interchannel interference aggravation, and communication quality will sharply descend.
When wlan device dispatched from the factory at present, calibration value deposited among the EEPROM after the crystal oscillator frequency calibration, and equipment reads calibration value from EEPROM when restarting like this, by calibration circuit calibration crystal oscillator frequency.The crystal frequency drift that this method can not the calibration environment variations in temperature causes, when ambient temperature differed larger when equipment ambient temperature of living in and factory's survey, the crystal oscillator frequency calibration was lost efficacy, and the orthogonality of OFDM is destroyed, communication quality worsens, and the facility environment adaptive capacity is poor.
Therefore, prior art has yet to be improved and developed.
Summary of the invention
The technical problem to be solved in the present invention is, defects for prior art, a kind of apparatus and method of the WIFI of raising access point frequency stability are provided, provide a kind of with the drift of variation of ambient temperature dynamic adjustments WLAN access point crystal oscillator, the method and apparatus that WLAN access point crystal oscillator output frequency precision is improved.The present invention uses thermistor and simple circuit to realize, has reduced cost and the complexity of equipment, has expanded simultaneously the scope of equipment adaptation region, promotes the reliability of WLAN access point communication.
The technical scheme that technical solution problem of the present invention adopts is as follows:
A kind of device that improves WIFI access point frequency stability wherein, comprises temperature detection circuit, voltage compensating circuit and crystal oscillator;
Described temperature detection circuit is connected with described voltage compensating circuit, is used for the variation of crystal detection actual working environment temperature and crystal standard operation temperature, and variations in temperature is converted into voltage difference outputs to described voltage compensating circuit;
Described voltage compensating circuit is connected with described crystal oscillator, is used for producing the crystal oscillator regulation voltage of a compensation and exporting described crystal oscillator to according to described voltage difference;
Described crystal oscillator is used for exporting corresponding oscillator signal under the control of crystal oscillator regulation voltage.
The device of described raising WIFI access point frequency stability, wherein, described temperature detection circuit comprises a voltage comparator, the 3rd resistance and the 4th thermistor;
The first input end of described voltage comparator is connected to reference voltage, described the 3rd resistance is attempted by between the first input end and the second input of described voltage comparator, and described the 4th thermistor is attempted by between second input and the 3rd earth terminal of described voltage comparator;
The output of described voltage comparator is connected to described voltage compensating circuit.
The device of described raising WIFI access point frequency stability, wherein, described voltage compensating circuit comprises the first resistance and the second resistance, one end of the first resistance is connected to described temperature detection circuit, the other end of the first resistance is connected with the second resistance, and the other end of the second resistance is connected to described crystal oscillator by the second electric capacity;
The common port that is connected with the second resistance at described the first resistance connects with reference to ground by the first electric capacity, and described the first resistance, the second resistance and the first electric capacity consist of a low-pass filter unit;
The common port that is connected with described the second electric capacity at described the second resistance connects with reference to ground by a variable capacitance diode;
Its OUT end of described crystal oscillator is connected to described the second electric capacity, and the GND end connects with reference to ground.
The device of described raising WIFI access point frequency stability, wherein, described crystal oscillator proportion is the crystal oscillator of 40MHZ.
The device of described raising WIFI access point frequency stability, wherein, described the 4th thermistor is the thermistor of negative temperature coefficient.
A kind of method that improves WIFI access point frequency stability wherein, comprises step:
A, the variation by temperature detection circuit crystal detection actual working environment temperature and crystal standard operation temperature is set, and variations in temperature is converted into voltage difference outputs to voltage compensating circuit;
B, voltage compensating circuit produce the crystal oscillator regulation voltage of a compensation and export crystal oscillator to according to described voltage difference;
C, crystal oscillator are exported corresponding oscillator signal under the control of described crystal oscillator regulation voltage;
Wherein, described temperature detection circuit comprises a voltage comparator, the 3rd resistance and the 4th thermistor;
The first input end of described voltage comparator is connected to reference voltage, described the 3rd resistance is attempted by between the first input end and the second input of described voltage comparator, and described the 4th thermistor is attempted by between second input and the 3rd earth terminal of described voltage comparator;
The output of described voltage comparator is connected to described voltage compensating circuit;
Described voltage compensating circuit comprises the first resistance and the second resistance, and an end of the first resistance is connected to described temperature detection circuit, and the other end of the first resistance is connected with the second resistance, and the other end of the second resistance is connected to described crystal oscillator by the second electric capacity;
The common port that is connected with the second resistance at described the first resistance connects with reference to ground by the first electric capacity, and described the first resistance, the second resistance and the first electric capacity consist of a low-pass filter unit;
The common port that is connected with described the second electric capacity at described the second resistance connects with reference to ground by a variable capacitance diode;
Its OUT end of described crystal oscillator is connected to described the second electric capacity, and the GND end connects with reference to ground.
The method of described raising WIFI access point frequency stability, wherein, described step B also comprises: described voltage difference is carried out low-pass filtering.
The apparatus and method of raising WIFI access point frequency stability provided by the present invention, owing to adopted temperature detection circuit and voltage compensating circuit to overcome WLAN access point crystal temperature effect poor accuracy, the not strong shortcoming of fixed voltage compensation adaptability.The present invention has taken into full account the impact of ambient temperature on WLAN access point communication quality, improves communication quality by improving the access point frequency accuracy, guarantees the orthogonality of OFDM subcarrier.Dynamic adjustments frequency accuracy simultaneously, the variations in temperature so that equipment can conform has guaranteed the communication reliability of WLAN access point.
Description of drawings
Fig. 1 is the OFDM spectrogram.
Fig. 2 is sinc function schematic diagram.
Fig. 3 is the principle of device block diagram of the raising WIFI access point frequency stability of the embodiment of the invention.
Fig. 4 is the device particular circuit configurations figure of the raising WIFI access point frequency stability of the embodiment of the invention.
Fig. 5 is the method flow diagram of the raising WIFI access point frequency stability of the embodiment of the invention.
Embodiment
A kind of apparatus and method that improve WIFI access point frequency stability of the present invention mainly are to utilize temperature detection circuit and voltage compensating circuit to overcome WLAN access point crystal temperature effect poor accuracy, the not strong shortcoming of fixed voltage compensation adaptability.For making purpose of the present invention, technical scheme and advantage clearer, clear and definite, developing simultaneously referring to accompanying drawing, the present invention is described in more detail for embodiment.Should be appreciated that specific embodiment described herein only in order to explain the present invention, is not intended to limit the present invention.
The device of a kind of WIFI of raising access point frequency stability that the embodiment of the invention provides as shown in Figure 3, mainly comprises temperature detection circuit 100, voltage compensating circuit 200 and crystal oscillator 300;
Described temperature detection circuit 100 is connected with described voltage compensating circuit 200, is mainly used in the variation of crystal detection actual working environment temperature and crystal standard operation temperature, and variations in temperature is converted into voltage difference outputs to described voltage compensating circuit 200;
Described voltage compensating circuit 200 and described crystal oscillator 300: be used for described voltage difference is carried out filtering, and export described crystal oscillator 300 to according to the crystal oscillator regulation voltage of filtered voltage difference generation one compensation;
Described crystal oscillator 300, be used under the control of crystal oscillator regulation voltage, exporting corresponding oscillator signal.
Preferably, such as Fig. 4, described temperature detection circuit 100 comprises a voltage comparator, the 3rd resistance R 3 and the 4th thermistor R4;
The first input end 1 of described voltage comparator is connected to reference voltage, described the 3rd resistance R 3 is attempted by between the first input end 1 and the second input 2 of described voltage comparator, and described the 4th thermistor R4 is attempted by between second input 2 and the 3rd earth terminal 3 of described voltage comparator; And the output of described voltage comparator is connected to described voltage compensating circuit 200.Wherein, described the 4th thermistor R4 is the thermistor of negative temperature coefficient.
As shown in Figure 4, described voltage compensating circuit 200 comprises the first resistance R 1 and the second resistance R 2, one end of the first resistance R 1 is connected to described temperature detection circuit 100, the other end of the first resistance R 1 is connected with the second resistance R 2, and the other end of the second resistance R 2 is connected to described crystal oscillator 300 by the second capacitor C 2.
And at the common port that described the first resistance R 1 is connected with the second resistance R 2, described the first resistance R 1, the second resistance R 2 and the first capacitor C 1 consist of a low-pass filter unit 210, as shown in Figure 4 with passing through the 1 connection reference of the first capacitor C; And at the common port that described the second resistance R 2 is connected with described the second capacitor C 2 with passing through variable capacitance diode D1 connection reference.
Further, as shown in Figure 4, described crystal oscillator 300 proportions are the crystal oscillator of 40MHZ, and its OUT end is connected to described the second electric capacity, and the GND end connects with reference to ground.
Shown in the embodiment of Fig. 4, improve the device of WIFI access point frequency stability, reference voltage at voltage comparator input 1 is stable, and voltage comparator input 2 is the voltage (this temperature-sensitive is negative temperature coefficient NTC-Negative Temperature Coefficient) on the 4th thermistor R4.Like this, when variations in temperature, voltage comparator then can detect corresponding variation magnitude of voltage, after the direct current of voltage comparator output carries out low-pass filtering through the first resistance R 1, the first capacitor C 1 and the second resistance R 2 in the low-pass filter unit 210, be added to variable capacitance diode D1 two ends as reverse bias voltage, produce the crystal oscillator regulation voltage of a compensation, be added to " OUT " end of 40MHZ crystal oscillator by the second capacitor C 2 for equivalent capacity as load capacitance.
Improve the device of WIFI access point frequency stability shown in the embodiment of Fig. 4 of the present invention, in the production debug process, estimate the resistance value of the 3rd resistance R 3 and the 4th thermistor R4.Use the R3 resistance of different resistance sizes instead, can change voltage comparator output end current value, voltage comparator output end current value driving voltage compensating circuit 200.The bucking voltage that voltage compensating circuit 200 produces is loaded into " OUT " end of 40MHZ crystal oscillator, so that 40MHz crystal oscillator precision frequency reaches ± 1pmm.When the accuracy of crystal reached, the resistance of the 3rd resistance R 3 had also just been determined.When producing, the accuracy of crystal oscillator 300 reaches by adjusting the 3rd resistance R 3 resistance values.
During normal operation, the resistance of the 3rd resistance R 3 is constant, because variation of ambient temperature causes that the 4th thermistor R4 resistance changes thereupon, this moment, the voltage comparator output end current changed, the crystal oscillator regulation voltage driving voltage compensating circuit 300 that produces a compensation is adjusted the frequency of crystal oscillator 300, make the output frequency of crystal oscillator 300 not produce drift with the variation of ambient temperature, be locked in 40MHZ ± 1pmm scope, reach preferably frequency accuracy.
Based on the device of the raising WIFI access point frequency stability of above-described embodiment, the embodiment of the invention also provides a kind of method of the WIFI of raising access point frequency stability, as shown in Figure 5, mainly may further comprise the steps:
In sum, the apparatus and method of raising WIFI access point frequency stability provided by the present invention, owing to having adopted temperature detection circuit and voltage compensating circuit to overcome WLAN access point crystal temperature effect poor accuracy, the not strong shortcoming of fixed voltage compensation adaptability.The present invention has taken into full account the impact of ambient temperature on WLAN access point communication quality, improves communication quality by improving the access point frequency accuracy, guarantees the orthogonality of OFDM subcarrier.Dynamic adjustments frequency accuracy simultaneously, the variations in temperature so that equipment can conform has guaranteed the communication reliability of WLAN access point.
Should be understood that, application of the present invention is not limited to above-mentioned giving an example, and for those of ordinary skills, can be improved according to the above description or conversion, and all these improvement and conversion all should belong to the protection range of claims of the present invention.
Claims (5)
1. a device that improves WIFI access point frequency stability is characterized in that, comprises temperature detection circuit, voltage compensating circuit and crystal oscillator;
Described temperature detection circuit is connected with described voltage compensating circuit, is used for the variation of crystal detection actual working environment temperature and crystal standard operation temperature, and variations in temperature is converted into voltage difference outputs to described voltage compensating circuit;
Described voltage compensating circuit is connected with described crystal oscillator, is used for producing the crystal oscillator regulation voltage of a compensation and exporting described crystal oscillator to according to described voltage difference;
Described crystal oscillator is used for exporting corresponding oscillator signal under the control of crystal oscillator regulation voltage;
Described temperature detection circuit comprises a voltage comparator, the 3rd resistance and the 4th thermistor;
The first input end of described voltage comparator is connected to reference voltage, described the 3rd resistance is attempted by between the first input end and the second input of described voltage comparator, and described the 4th thermistor is attempted by between second input and the 3rd earth terminal of described voltage comparator;
The output of described voltage comparator is connected to described voltage compensating circuit;
Described voltage compensating circuit comprises the first resistance and the second resistance, and an end of the first resistance is connected to described temperature detection circuit, and the other end of the first resistance is connected with the second resistance, and the other end of the second resistance is connected to described crystal oscillator by the second electric capacity;
The common port that is connected with the second resistance at described the first resistance connects with reference to ground by the first electric capacity, and described the first resistance, the second resistance and the first electric capacity consist of a low-pass filter unit;
The common port that is connected with described the second electric capacity at described the second resistance connects with reference to ground by a variable capacitance diode;
Its OUT end of described crystal oscillator is connected to described the second electric capacity, and the GND end connects with reference to ground.
2. the device of described raising WIFI access point frequency stability according to claim 1 is characterized in that, described crystal oscillator proportion is the crystal oscillator of 40MHZ.
3. the device of described raising WIFI access point frequency stability according to claim 1 is characterized in that, described the 4th thermistor is the thermistor of negative temperature coefficient.
4. a method that improves WIFI access point frequency stability is characterized in that, comprises step:
A, the variation by temperature detection circuit crystal detection actual working environment temperature and crystal standard operation temperature is set, and variations in temperature is converted into voltage difference outputs to voltage compensating circuit;
B, voltage compensating circuit produce the crystal oscillator regulation voltage of a compensation and export crystal oscillator to according to described voltage difference;
C, crystal oscillator are exported corresponding oscillator signal under the control of described crystal oscillator regulation voltage;
Wherein, described temperature detection circuit comprises a voltage comparator, the 3rd resistance and the 4th thermistor;
The first input end of described voltage comparator is connected to reference voltage, described the 3rd resistance is attempted by between the first input end and the second input of described voltage comparator, and described the 4th thermistor is attempted by between second input and the 3rd earth terminal of described voltage comparator;
The output of described voltage comparator is connected to described voltage compensating circuit;
Described voltage compensating circuit comprises the first resistance and the second resistance, and an end of the first resistance is connected to described temperature detection circuit, and the other end of the first resistance is connected with the second resistance, and the other end of the second resistance is connected to described crystal oscillator by the second electric capacity;
The common port that is connected with the second resistance at described the first resistance connects with reference to ground by the first electric capacity, and described the first resistance, the second resistance and the first electric capacity consist of a low-pass filter unit;
The common port that is connected with described the second electric capacity at described the second resistance connects with reference to ground by a variable capacitance diode;
Its OUT end of described crystal oscillator is connected to described the second electric capacity, and the GND end connects with reference to ground.
5. the method for described raising WIFI access point frequency stability according to claim 4 is characterized in that, described step B also comprises: described voltage difference is carried out low-pass filtering.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201010558837 CN102025320B (en) | 2010-11-25 | 2010-11-25 | Device and method for improving frequency stability of WIFI (wireless fidelity) access point |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201010558837 CN102025320B (en) | 2010-11-25 | 2010-11-25 | Device and method for improving frequency stability of WIFI (wireless fidelity) access point |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102025320A CN102025320A (en) | 2011-04-20 |
| CN102025320B true CN102025320B (en) | 2013-01-23 |
Family
ID=43866276
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201010558837 Expired - Fee Related CN102025320B (en) | 2010-11-25 | 2010-11-25 | Device and method for improving frequency stability of WIFI (wireless fidelity) access point |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102025320B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108965446A (en) * | 2018-07-27 | 2018-12-07 | 安徽安为科技有限公司 | Based on WIFI yard large capacity file dumping system |
| CN109541553A (en) * | 2018-11-28 | 2019-03-29 | 四川九洲电器集团有限责任公司 | A kind of synchronised clock feed circuit |
| CN110932718B (en) * | 2019-11-29 | 2023-01-24 | 紫光展讯通信(惠州)有限公司 | Method, device and equipment for calibrating clock frequency of crystal oscillator and storage medium |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1139500A (en) * | 1994-11-29 | 1997-01-01 | 摩托罗拉公司 | Low power temperature compensated crystal oscillator |
| CN1211354A (en) * | 1996-12-17 | 1999-03-17 | 摩托罗拉公司 | Temperature compensation circuit for a crystal oscillator and method of providing same |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7495484B1 (en) * | 2007-07-30 | 2009-02-24 | General Instrument Corporation | Programmable frequency multiplier |
-
2010
- 2010-11-25 CN CN 201010558837 patent/CN102025320B/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1139500A (en) * | 1994-11-29 | 1997-01-01 | 摩托罗拉公司 | Low power temperature compensated crystal oscillator |
| CN1211354A (en) * | 1996-12-17 | 1999-03-17 | 摩托罗拉公司 | Temperature compensation circuit for a crystal oscillator and method of providing same |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102025320A (en) | 2011-04-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104184527B (en) | Transmission power measuring device and transmission power measuring method | |
| US5731772A (en) | Method and apparatus for compensation for a DC voltage offset of a digital to analog converter | |
| CN102065041B (en) | Method, device and system for inhibiting local oscillator leakage | |
| US20150381337A1 (en) | Segmented digital-to-time converter calibration | |
| CN103001627B (en) | Quartz-crystal resonance frequency fine adjustment control system | |
| CN102025320B (en) | Device and method for improving frequency stability of WIFI (wireless fidelity) access point | |
| CN108225495A (en) | A kind of capacitance level transducer on-line measurement system and its method | |
| CN104243025A (en) | High-precision extinction ratio test method and system | |
| CN101977085A (en) | Method and system for controlling and calibrating TD-LTE terminal automatic frequency | |
| CN106549720A (en) | A kind of method and mobile terminal for improving mobile terminal radio frequency frequency deviation | |
| CN114047377B (en) | Inductance-compensated transient step current standard construction method | |
| CN106230435B (en) | Clock source generating means and method | |
| CN104270097B (en) | The processing system and method that upconversion transmitter local-oscillator leakage and sideband suppress | |
| CN103746720B (en) | Wireless communication module method of adjustment | |
| CN108768451B (en) | Power line carrier integrated test system and test method | |
| CN104703268B (en) | filter power compensation method, device and user terminal | |
| CN114326924B (en) | Signal processing method and storage medium | |
| CN110113005A (en) | 5G standard source high-frequency crystal oscillator circuit | |
| CN105911388A (en) | Test platform debugging method and system | |
| CN103746714A (en) | Digital compensation method of receiver radio frequency response | |
| CN113364550B (en) | Clock adjusting method and device | |
| CN112019317B (en) | Frequency calibration method and device, storage medium and electronic device | |
| CN209879334U (en) | Computer analog signal calibration system | |
| US20150145536A1 (en) | Methods and Systems for Production Testing of Capacitors | |
| CN204669342U (en) | Based on the Low phase noise small sized wide-band signal source of PLL frequency multiplication and frequency splitting technology |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130123 |