CN108388107A - GPS real time clock circuits and timing system - Google Patents
GPS real time clock circuits and timing system Download PDFInfo
- Publication number
- CN108388107A CN108388107A CN201810103504.4A CN201810103504A CN108388107A CN 108388107 A CN108388107 A CN 108388107A CN 201810103504 A CN201810103504 A CN 201810103504A CN 108388107 A CN108388107 A CN 108388107A
- Authority
- CN
- China
- Prior art keywords
- gps
- chip
- real time
- impedance matching
- clock
- 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.)
- Granted
Links
- 230000002123 temporal effect Effects 0.000 claims description 8
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 6
- 230000005611 electricity Effects 0.000 claims description 4
- 239000012212 insulator Substances 0.000 claims description 3
- 238000000034 method Methods 0.000 abstract description 4
- 238000011161 development Methods 0.000 abstract description 2
- 230000005540 biological transmission Effects 0.000 description 5
- 239000013078 crystal Substances 0.000 description 5
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 1
- 238000012356 Product development Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 235000013399 edible fruits Nutrition 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G04—HOROLOGY
- G04R—RADIO-CONTROLLED TIME-PIECES
- G04R20/00—Setting the time according to the time information carried or implied by the radio signal
- G04R20/02—Setting the time according to the time information carried or implied by the radio signal the radio signal being sent by a satellite, e.g. GPS
Landscapes
- Engineering & Computer Science (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Electric Clocks (AREA)
Abstract
Present disclosure GPS real time clock circuits and timing system.The circuit includes pcb board and the impedance matching circuit being arranged on the pcb board, GPS chip, micro-control unit, clock chip, antenna power and filter circuit, the antenna power is connect with one end of the filter circuit, and the other end of the filter circuit connect to form the first tie point with the impedance matching circuit；The impedance matching of the impedance matching circuit includes the impedance matching of the antenna power and the filter circuit and the GPS chip, the impedance matching of the GPS chip and GPS antenna；It further include the first shielding line, first shielding line has the characteristic impedance needed for transmitting radio frequency signal, one end of first shielding line is connect with first tie point, and the other end of first shielding line draws the outside of the GPS real time clock circuits for being connect with GPS antenna.The timing system includes the circuit.The present invention can simplify the process of impedance matching, shorten the development cycle of product.
Description
Technical field
The present invention relates to RF application, more particularly to a kind of GPS real time clock circuits and the school for including the clock circuit
When system.
Background technology
GPS real time clock circuits are calibrated using GPS signal, use radio frequency.Radio frequency (RF, Radio
Frequency the electromagnetic frequency that can be radiated space, radio frequency abbreviation RF radio frequencies, that is, radio-frequency current) are indicated, it is a kind of
High-frequency ac changes the abbreviation of electromagnetic wave.
Radio-frequency antenna receives radiofrequency signal, in order to obtain maximum signal power, it is necessary that load resistance is with signal
Source internal resistance is equal.Singal source resistance is equal in magnitude with the characteristic impedance of connect transmission line and phase is identical or the characteristic of transmission line
Impedance is identical as the equal in magnitude and phase of connect load impedance, be referred to as transmission line input terminal or output in impedance
Matching status, referred to as impedance matching.The intensity for receiving signal is directly affected whether the matching of impedance and receives stability.
It makes or when relevant with the radio frequency module of use, needs the impedance matching for considering radio-frequency antenna, be that these modules are set
Count impedance matching circuit.The impedance matching of radio-frequency antenna is the problem of puzzled many Hardware Engineers, and impedance matching circuit is to electricity
The requirement of road plate is very high, causes cost also very high.Radio frequency have it is very strong professional, to Hardware Engineer profession require very
Height, and radio frequency testing instrument is expensive so that it makes or high using the cost with the relevant module of radio frequency.
GPS device generally all can be using active antenna, the signal wire of GPS active antennas while the again power cord as active antenna, such as
Fruit power supply, which handles the bad quality of reception for directly affecting GPS signal, leads to search that star is unstable, this also gives the impedance of radio-frequency antenna
With increasing difficulty.
In addition, for GPS real time clock circuits, GPS data needs the time when being written to RTC by MCU parsings, presses
According to 400K communication speed write-in the second, point, when, week, day, Month And Year, need the time of 20uS or so, wanted to clock system
It is also that can not be ignored to ask higher place, 20uS.
Invention content
The purpose of the present invention is to solve the impedance matchings for needing to consider the problems of radio-frequency antenna in the prior art, propose
A kind of GPS real time clock circuits and the timing system for including the clock circuit.
In order to solve the above technical problems, the present invention uses following technical scheme：
GPS real time clock circuits, including pcb board and be arranged on the pcb board impedance matching circuit, GPS chip,
Micro-control unit, clock chip, antenna power and filter circuit, the impedance matching circuit, the GPS chip, the micro-control
Unit processed and the clock chip are sequentially connected, and the antenna power is connect with one end of the filter circuit, the filtered electrical
The other end on road connect to form the first tie point with the impedance matching circuit；The impedance matching of the impedance matching circuit includes
The antenna power and the filter circuit and the impedance matching of the GPS chip, the impedance of the GPS chip and GPS antenna
Matching；Further include the first shielding line, first shielding line has the characteristic impedance needed for transmitting radio frequency signal, first screen
The one end for covering line is connect with first tie point, and the other end of first shielding line draws the GPS real time clock circuits
Outside for being connect with GPS antenna.
In some preferred embodiments, the GPS chip is also connect with the clock chip with to the clock core
Piece sends 1PPS signals；The clock chip includes millisecond counter and second counter, and the millisecond counter is used for described
Second counter sends second signal, and the clock chip is used for the millisecond in the failing edge for the 1PPS signals for detecting GPS
Counter O reset；The micro-control unit is used to extract GPS time information from GPS data and in the 1PPS for detecting GPS
When temporal information being written to the clock chip to realize school when the failing edge of signal.
In some preferred embodiments, first shielding line is coaxial cable, and the coaxial cable is from the inside to the outside
Include center copper wire, insulator, reticulated conductive layer and wire outer skin successively.
In further preferred embodiment, the center copper wire is connect with the center of first tie point, described
Reticulated conductive layer is connected to ground.
In some preferred embodiments, first shielding line has 50 ohm characteristic impedances.
In some preferred embodiments, the clock chip is provided with temperature-compensation circuit.
In some preferred embodiments, the clock chip can send the benchmark for timing to the GPS chip
Pulse signal；The GPS chip can carry out timing according to the reference pulse signal.
In some preferred embodiments, the micro-control unit carries out school by iic bus to the clock chip
When.
In some preferred embodiments, further include stand-by power supply, the stand-by power supply is used to be the clock chip
Power supply.
On the other hand, the present invention also provides a kind of timing system, which includes any of the above-described GPS real-time clocks electricity
Road.
Compared with prior art, beneficial effects of the present invention have：
Antenna power and filter circuit are arranged with other circuit units on pcb board, form an entirety, impedance matching electricity
The impedance matching on road includes the impedance matching of antenna power and filter circuit and GPS chip, that is, considers power filter
Influence to radiofrequency signal.From the first tie point draw have transmitting radio frequency signal needed for characteristic impedance the first shielding line with
GPS antenna connect, the first shielding line and clock circuit are an entirety, in this way, use when directly by the first shielding line with
GPS antenna connects, and does not have to consider the problems of impedance matching, greatly simplifies the process of user's impedance matching, shorten product
Development cycle, to reduce cost.
In a preferred embodiment, the present invention also has the advantages that：
Further, the 1PPS signals of GPS are whole second signals, failing edge indicate the end of current second, next second
Start, clock chip resets millisecond counter in the failing edge for the 1PPS signals for detecting GPS, and millisecond counter is opened again
Beginning timing, micro-control unit then also in the failing edge for the 1PPS signals for detecting GPS by when, the temporal informations such as minute, second are written
It,, can be with smart when high-ranking officers since the failing edge of 1PPS signals is up to nanosecond rank when thereby realizing school to clock chip
Degree accomplishes nanosecond rank, when to realize high-precision school.
Description of the drawings
Fig. 1 shows the circuit structure of the GPS real time clock circuits of the present invention；
Fig. 2 shows the structures of the GPS antenna of the present invention；
Fig. 3 shows the internal structure of the first shielding line of the present invention；
Fig. 4 shows a kind of circuit structure of variant of the GPS real time clock circuits of the present invention；
Fig. 5 shows the circuit structure of another variant of the GPS real time clock circuits of the present invention；
Fig. 6 shows the internal structure of the clock chip of the present invention；
Fig. 7 shows the circuit structure of the third variant of the GPS real time clock circuits of the present invention；
Fig. 8 shows the circuit structure of the timing system of the present invention.
Specific implementation mode
It elaborates below to embodiments of the present invention.It is emphasized that following the description is only exemplary,
The range being not intended to be limiting of the invention and its application.
With reference to figure 1, GPS real time clock circuits include pcb board 1 and the impedance matching circuit being arranged on pcb board 1 11,
GPS chip 12, micro-control unit 13, clock chip 14, antenna power 15 and filter circuit 16, impedance matching circuit 11, GPS cores
Piece 12, micro-control unit 13 and clock chip 14 are sequentially connected, and antenna power 15 is connect with one end of filter circuit 16, filtered electrical
The other end on road 16 is connect with impedance matching circuit 11 forms the first tie point 101.First tie point 101 is the weldering on pcb board 1
Disk, the connection with pcb board 1.
With reference to figure 1 and Fig. 2, the impedance matching of impedance matching circuit 11 includes antenna power 15 and filter circuit 16 and GPS
The impedance matching of chip 12, the impedance matching of GPS chip 12 and GPS antenna 21.
Further include the first shielding line 17 with reference to figure 1, the first shielding line 17 has the characteristic resistance needed for transmitting radio frequency signal
Anti-, one end of the first shielding line 17 is connect with the first tie point 101, and the other end of the first shielding line 17 draws GPS real-time clocks
The outside of circuit with GPS antenna 21 for connecting.
With reference to figure 1 and Fig. 2, the operation principle of GPS real time clock circuits is such：GPS real time clock circuit uses have
Source antenna receives the radiofrequency signal from satellite, that is to say, that GPS antenna 21 is active antenna.Filter circuit 16 is arranged in day
Between line power supply 15 and GPS antenna 21, filter circuit 16 is used for the filtering of antenna power 15.Antenna power 15 is GPS antenna 21
Power supply, GPS antenna 21 receive radiofrequency signal, and radiofrequency signal is transferred to GPS chip 12, GPS chip 12 through the first shielding line 17 again
Sent to micro-control unit 13 after handling radiofrequency signal include temporal information GPS data, micro-control unit 13 is right
The GPS data that GPS chip 12 is sent is parsed to extract GPS time and geographical location information, and micro-control unit 13 passes through IIC
Bus is by temporal information and/or geographical location information write clock chip 14.
As described above, antenna power 15 and filter circuit 16 are arranged with other circuit units on pcb board, one is formed
A entirety, the impedance matching of impedance matching circuit 11 include the impedance of antenna power 15 and filter circuit 16 and GPS chip 12
Matching, that is, consider influence of the power filter to radiofrequency signal.Being drawn from the first tie point 101 has transmitting radio frequency signal
First shielding line 17 of required characteristic impedance is connect with GPS antenna 21, and the first shielding line 17 and clock circuit are an entirety,
In this way, directly connecting the first shielding line 17 with GPS antenna 21 when use, centre is eliminated by GPS real time clock circuits
First shielding line 17 included to the circuit instead GPS real time clock circuits of the impedance matching of GPS antenna 21,
It is exactly the impedance matching for not having to consider GPS antenna 21 and clock circuit, greatly simplifies the process of user's impedance matching, shortens
The development cycle of product, to reducing cost.
The present invention is further illustrated below：
First shielding line 17 is coaxial cable, which has 50 ohm characteristic impedances, penetrated for specially transmitting GPS
Frequency signal can also select the coaxial cable of other characteristic impedances according to actual needs certainly.With reference to figure 3, the first shielding line 17
Include center copper wire 171, insulator 172, reticulated conductive layer 173 and wire outer skin 174 successively from the inside to the outside.Preferably to shield
Interference, such as electrical Interference, center copper wire 171 are connect with the center of the first tie point 101, and reticulated conductive layer 173 is connected to ground,
For example it connect with the ground of antenna power 15 or is connect with the ground of the power supply (not shown) of GPS real time clock circuits.Clock
Chip 14 is provided with the clock chip of temperature-compensation circuit, by temperature-compensation circuit come compensation temperature to the shadow of clock chip
It rings, to improve accuracy of timekeeping.
With reference to figure 4, stand-by power supply 18 can be also set, and stand-by power supply 18 is used to power for clock chip 14, to ensure GPS
Real time clock circuit continuously can reliably provide correct time information.
The present invention can also be achieved：
GPS chip 12 also connect with clock chip 14 with to clock chip 14 send 1PPS (pulse per second,
1PPS=1Hz=1 times/second) signal.With reference to figure 5, this connection can be connected by pin, for example GPS chip 12 is equipped with
1PPS sends pin 1201, and being then equipped with 1PPS on clock chip 14 receives pin 1401, and 1PPS sends pin 1201 and 1PPS and connects
Closed tube foot 1401 connects；It can also be and wirelessly connect, such as bluetooth.
With reference to figure 6, clock chip 14 includes millisecond counter 141 and second counter 142.Certainly, for some clock cores
Piece also has minute counter, hour counter, day counter etc., and the present invention can be applicable in.Millisecond counter 141 records
Millisecond information, after receiving 32768 (215) pulse signals, millisecond counter 141 sends signal to second counter 142, so that
Second counter 142 counts the second.
Clock chip 14 can reset millisecond counter 141 in the failing edge for the 1PPS signals for detecting GPS.
Micro-control unit 13 can be from extraction GPS time information in GPS data and in the case where detecting the 1PPS signals of GPS
Drop along when temporal information is written to clock chip 14 to realize school when.At this point, micro-control unit 13 be when will be from GPS,
In minute, second temporal information write clock chip 14, certainly, according to actual conditions, the times such as day, week, the moon, year can also be believed
It ceases in write clock chip 14.Specifically, micro-control unit 13 is calibrated clock chip 14 by iic bus.GPS's
1PPS signals are whole second signals, and failing edge indicates that the end of current second, beginning in next second, clock chip 14 are detecting
Millisecond counter 141 is reset when the failing edge of the 1PPS signals of GPS, millisecond counter 141 restarts timing, microcontroller list
Member 13 then also in the failing edge for the 1PPS signals for detecting GPS by when, the temporal informations such as minute, second be written to clock chip 14,
When thereby realizing school, since the failing edge of 1PPS signals is up to nanosecond rank, correcting delay precision can be accomplished nanosecond
Rank, when to realize high-precision school.
Based on above explanation, the present invention also has other realization method：
With reference to figure 6, clock chip 14 is equipped with the crystal oscillator 143 for generating reference pulse signal, such as frequency
It is 32.768kHz without source crystal, the pulse signal of 32768Hz can be transmitted without source crystal for this, certainly, also may be used according to actual needs
With the other frequencies of use without source crystal.
Clock chip 14 can send the reference pulse signal for timing to GPS chip 12.With reference to figure 7, the mode of transmission
It can be sent by pin, for example clock chip 14 is equipped with reference signal and sends pin 1402, and base is then equipped on GPS chip 12
Calibration signal receives pin 1202, and reference signal sends pin 1402 and connect with reference signal reception pin 1202, can also be passed through
Wirelessly send.
With reference to figure 7, GPS chip 12 is equipped with GPS timing units 121, and GPS timing units 121 are used for according to clock chip 14
The reference pulse signal of transmission carries out timing.
It is such to be advantageous in that：Since GPS chip 12 is also required to timing in itself, when GPS chip 12 can not receive radio frequency
When signal, that is, when can not receive the GPS signal of satellite, base that GPS chip 12 can also be sent according to clock chip 14
Quasi- pulse signal carries out timing, it is ensured that GPS chip 12 under any circumstance can timing.Meanwhile GPS chip 12 is without external
Crystal oscillator, cost-saved and pcb board space.
The present invention also provides a kind of timing systems, with reference to figure 8, timing system include above-mentioned GPS real time clock circuits 100,
GPS antenna 21 and the antenna socket 22 for connecting GPS antenna 21 with GPS real time clock circuits 100.
The above content is specific/preferred embodiment further description made for the present invention is combined, cannot recognize
The specific implementation of the fixed present invention is confined to these explanations.For those of ordinary skill in the art to which the present invention belongs,
Without departing from the inventive concept of the premise, some replacements or modification can also be made to the embodiment that these have been described,
And these are substituted or variant all shall be regarded as belonging to protection scope of the present invention.
Claims (10)
1.GPS real time clock circuits, it is characterised in that：Including pcb board and the impedance matching being arranged on pcb board electricity
Road, GPS chip, micro-control unit, clock chip, antenna power and filter circuit, the impedance matching circuit, the GPS cores
Piece, the micro-control unit and the clock chip are sequentially connected, and the antenna power is connect with one end of the filter circuit,
The other end of the filter circuit connect to form the first tie point with the impedance matching circuit；The resistance of the impedance matching circuit
Anti- matching includes impedance matching, the GPS chip and the GPS of the antenna power and the filter circuit and the GPS chip
The impedance matching of antenna；Further include the first shielding line, first shielding line has the characteristic impedance needed for transmitting radio frequency signal,
One end of first shielding line is connect with first tie point, and the other end of first shielding line draws the GPS realities
When clock circuit outside for being connect with GPS antenna.
2. GPS real time clock circuits according to claim 1, it is characterised in that：The GPS chip also with the clock core
Piece connection to the clock chip to send 1PPS signals；The clock chip includes millisecond counter and second counter, described
Millisecond counter is used to send second signal to the second counter, and the clock chip is used in the 1PPS signals for detecting GPS
Failing edge when the millisecond counter is reset；The micro-control unit be used for from GPS data extract GPS time information with
And when in the failing edge for the 1PPS signals for detecting GPS temporal information being written to the clock chip to realize school.
3. GPS real time clock circuits according to claim 1, it is characterised in that：First shielding line is coaxial cable,
The coaxial cable includes center copper wire, insulator, reticulated conductive layer and wire outer skin successively from the inside to the outside.
4. GPS real time clock circuits according to claim 3, it is characterised in that：The center copper wire connects with described first
The center of contact connects, and the reticulated conductive layer is connected to ground.
5. GPS real time clock circuits according to claim 1, it is characterised in that：First shielding line has 50 ohm
Characteristic impedance.
6. GPS real time clock circuits according to claim 1, it is characterised in that：The clock chip is provided with temperature benefit
Repay circuit.
7. GPS real time clock circuits according to claim 1 or 2, it is characterised in that：The clock chip can be to described
GPS chip sends the reference pulse signal for timing；The GPS chip can carry out timing according to the reference pulse signal.
8. GPS real time clock circuits according to claim 1, it is characterised in that：The micro-control unit passes through iic bus
The clock chip is calibrated.
9. GPS real time clock circuits according to any one of claims 1 to 6, it is characterised in that：Further include stand-by power supply,
The stand-by power supply is used to power for the clock chip.
10. timing system, including GPS real time clock circuits as described in any one of claim 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810103504.4A CN108388107B (en) | 2018-02-01 | 2018-02-01 | GPS real-time clock circuit and timing system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810103504.4A CN108388107B (en) | 2018-02-01 | 2018-02-01 | GPS real-time clock circuit and timing system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108388107A true CN108388107A (en) | 2018-08-10 |
| CN108388107B CN108388107B (en) | 2023-11-21 |
Family
ID=63074939
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810103504.4A Active CN108388107B (en) | 2018-02-01 | 2018-02-01 | GPS real-time clock circuit and timing system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108388107B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110457248A (en) * | 2019-08-07 | 2019-11-15 | 深圳市兴威帆电子技术有限公司 | A method of improving the reliability of real-time timepiece chip serial data transmission |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2497348Y (en) * | 2000-11-15 | 2002-06-26 | 柴超 | Time-calibrating control device |
| KR20060055573A (en) * | 2004-11-17 | 2006-05-23 | 모바일 어플라이언스 주식회사 | Coupling device for coupling the interior gps antenna signal and the exterior gps antenna signal |
| CN101308955A (en) * | 2008-05-22 | 2008-11-19 | 杭州中科微电子有限公司 | Radio frequency integrated GPS active antenna |
| CN102623806A (en) * | 2011-09-07 | 2012-08-01 | 嘉兴联星微电子有限公司 | High-stability low-noise GPS (Global Positioning System) active antenna |
| CN102780499A (en) * | 2012-06-26 | 2012-11-14 | 国民技术股份有限公司 | Antenna sharing circuit, radio-frequency circuit and terminal device |
| CN203311175U (en) * | 2013-06-13 | 2013-11-27 | 吉林大学 | GPS time service and DDS combined device for realizing stable high-speed synchronous clock |
| CN103913987A (en) * | 2014-04-26 | 2014-07-09 | 广西电网公司电力科学研究院 | GPS timing system and method for obtaining precise time reference through GPS timing system |
| CN106814377A (en) * | 2016-12-15 | 2017-06-09 | 努比亚技术有限公司 | A kind of GPS radio frequency front-end circuit |
| CN207884609U (en) * | 2018-02-01 | 2018-09-18 | 深圳市兴威帆电子技术有限公司 | Radio circuit and radio frequency system |
-
2018
- 2018-02-01 CN CN201810103504.4A patent/CN108388107B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2497348Y (en) * | 2000-11-15 | 2002-06-26 | 柴超 | Time-calibrating control device |
| KR20060055573A (en) * | 2004-11-17 | 2006-05-23 | 모바일 어플라이언스 주식회사 | Coupling device for coupling the interior gps antenna signal and the exterior gps antenna signal |
| CN101308955A (en) * | 2008-05-22 | 2008-11-19 | 杭州中科微电子有限公司 | Radio frequency integrated GPS active antenna |
| CN102623806A (en) * | 2011-09-07 | 2012-08-01 | 嘉兴联星微电子有限公司 | High-stability low-noise GPS (Global Positioning System) active antenna |
| CN102780499A (en) * | 2012-06-26 | 2012-11-14 | 国民技术股份有限公司 | Antenna sharing circuit, radio-frequency circuit and terminal device |
| CN203311175U (en) * | 2013-06-13 | 2013-11-27 | 吉林大学 | GPS time service and DDS combined device for realizing stable high-speed synchronous clock |
| CN103913987A (en) * | 2014-04-26 | 2014-07-09 | 广西电网公司电力科学研究院 | GPS timing system and method for obtaining precise time reference through GPS timing system |
| CN106814377A (en) * | 2016-12-15 | 2017-06-09 | 努比亚技术有限公司 | A kind of GPS radio frequency front-end circuit |
| CN207884609U (en) * | 2018-02-01 | 2018-09-18 | 深圳市兴威帆电子技术有限公司 | Radio circuit and radio frequency system |
Non-Patent Citations (1)
| Title |
|---|
| 张露: "基于GPS的高稳频率源设计与实现", 《中国优秀硕士学位论文全文数据库 信息科技辑》, vol. 2011, no. 4, pages 1135 - 344 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110457248A (en) * | 2019-08-07 | 2019-11-15 | 深圳市兴威帆电子技术有限公司 | A method of improving the reliability of real-time timepiece chip serial data transmission |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108388107B (en) | 2023-11-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| WO2017219899A1 (en) | Near field communication antenna for intelligent wearable product and intelligent wearable product | |
| WO2019114622A1 (en) | Antenna tuning circuit, antena apparatus and mobile terminal | |
| CN104659927A (en) | Wireless charging receiving device and wireless charging system using the same | |
| WO2017177495A1 (en) | Circularly polarized antenna and wireless communication device thereof | |
| CN110765729B (en) | Integrated extensible satellite communication service system based on SOC (System on chip) | |
| CN210222766U (en) | Object capable of contactless communication with a reader by active charge modulation | |
| CN106848535B (en) | Wearing equipment with wireless communication device | |
| US20100295569A1 (en) | Rf performance test structure with electronic switch function | |
| CN204836148U (en) | Variable bandwidth double conversion multichannel receiver | |
| CN104749948A (en) | Wearable electronic device | |
| CN207884609U (en) | Radio circuit and radio frequency system | |
| CN108388107A (en) | GPS real time clock circuits and timing system | |
| CN105871411B (en) | Radio frequency chip, radio circuit and electronic equipment | |
| CN104115414A (en) | Wireless communication apparatus and antenna apparatus | |
| CN112531328A (en) | GPS antenna and intelligent wearable device | |
| CN104199273A (en) | Watch without button and handle | |
| CN207851522U (en) | watch device | |
| GB413917A (en) | Improvements in or relating to radio receiving systems | |
| CN202217056U (en) | Northern Dipper global positioning system (GPS) double-module time service receiving device | |
| CN209046635U (en) | A kind of radio frequency signal frequency auto-calibration circuits | |
| US10193214B2 (en) | Near field communication on a seamless metal band and metal backed device | |
| CN107086356B (en) | Antenna Module and Terminal | |
| CN211352189U (en) | Radio frequency communication circuit, terminal wireless network assembly and electronic equipment | |
| CN104777381A (en) | Double-antenna electromagnetic interference testing method and system | |
| CN103702454A (en) | Beidou cluster data transmission terminal equipment and system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |