CN202150850U - Frequency synthesizing device using GNSS second pulse for rapid modification - Google Patents
Frequency synthesizing device using GNSS second pulse for rapid modification Download PDFInfo
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- CN202150850U CN202150850U CN201120234394U CN201120234394U CN202150850U CN 202150850 U CN202150850 U CN 202150850U CN 201120234394 U CN201120234394 U CN 201120234394U CN 201120234394 U CN201120234394 U CN 201120234394U CN 202150850 U CN202150850 U CN 202150850U
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- crystal oscillator
- pps
- frequency synthesizer
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Abstract
The utility model provides a frequency synthesizing device using GNSS (Global Navigation Satellite System) second pulse for rapid modification. The frequency synthesizing device includes a GNSS receiver, a crystal oscillating frequency detecting and frequency synthesizer control word calculating circuit and a DDS (Direct Digital Frequency Synthesizer). A clock terminal of the crystal oscillating frequency detecting and frequency synthesizer control word calculating circuit connects with a crystal oscillator. Nominal frequency value is input into an input terminal of the crystal oscillating frequency detecting and frequency synthesizer control word calculating circuit and the input terminal connects with a GNSS receiver for receiving time service data and second pulse. The output terminal of crystal oscillating frequency detecting and frequency synthesizer control word calculating circuit connects with the DDS and outputs modified frequency synthesizer control word and a clock based on crystal oscillating. In the utility model, the GNSS second pulse is utilized for modifying an expected open loop of DDS (Direct Digital Frequency Synthesis) output nominal frequency directly. And the frequency synthesizing device using the GNSS second pulse for rapid modification in the utility model has beneficial effects of fast modification speed and high precision.
Description
Technical field
The utility model relates to a kind of high-precision apparatus for frequency synthesizing, relates in particular to the apparatus for frequency synthesizing that a kind of GNSS of utilization pulse per second (PPS) is revised fast, be used for GMDSS (Global Maritime Distress and Safety Syst) in/the high frequency radio radio station.
Background technology
Medium-high frequency (MF/HF) combination radio station is the important component part of GMDSS (Global Maritime Distress and Safety Syst), supports DSC (digital selective calling) communication, NBDP (the direct printing telegraph in arrowband) communication to communicate by letter with SSB (monolateral band).The MF (intermediate frequency) and HF (high frequency) wave band of maritime radio telephone supported in the combination radio station, and wherein MF audio range frequency scope is 1605～4000kHz, and the HF wave band is 4～27.5MHz.The medium-high frequency combined electrical relatives of Taiwan compatriots living on the Mainland are far away in communication distance, and reliability is high, can use in all sea areas, and be one of indispensable equipment of overocean communications.
International Maritime Organization (IMO) resolution A.806 (19) " can be carried out Speech Communication; Narrow sideband is directly printed and the boat-carrying MF/HF radio station of digital selective calling " and standard IEC 61097-9 " GMDSS-the 9th part: can carry out Speech Communication of International Power tissue; Narrow sideband is directly printed and the boat-carrying MF/HF band transmitter and the receiver-operation of equipment performance requirement of digital selective calling, and method of testing and test result require " performance of this kind equipment has been made detail requirement.Wherein the frequency stability of equipment requires to after hot machine accomplishes, frequency accuracy at 10Hz with interior (seeing A.806 B2 chapters and sections and 4.2 chapters and sections of IEC 61097-9).
By maximum operating frequency is that 27.5MHz calculates, and then the frequency stability in medium-high frequency combination radio station should be superior to 0.36ppm (1,000,000/), must adopt constant-temperature crystal oscillator just can meet the demands generally speaking.Constant-temperature crystal oscillator (Oven Controlled Crystal Oscillator; Be called for short OCXO) the abbreviation constant-temperature crystal oscillator; Utilize the constant-temperature crystal oscillator groove to make the temperature of quartz-crystal resonator in the crystal oscillator keep constant, will change the oscillator output frequency variable quantity that causes by environment temperature and control to minimum.OCXO is made up of thermostat control circuit and pierce circuit.Because the temperature of thermostat is usually above ambient temperature; So the time of preheating must be arranged during work; The regulation that the standard of this IMO and IEC is also made: " if equipment comprise some need heat could operate as normal device, like crystal oscillator, the so hot machine time can be 30 minutes.”
Present medium-high frequency combined electrical Daepori is all over the technical scheme that adopts constant-temperature crystal oscillator, and equipment cost is high, start long problem warm-up time but brought thus.
Because medium-high frequency combination radio station and GNSS GLONASS (for example GPS) combination are used, and can adopt the time service information of GNSS that the frequency of medium-high frequency combined electrical platform is calibrated.The Chinese patent " device and its implementation of a kind of dynamic adjustment WiMAX base station crystal oscillator stability " of the Chinese patent of the patent No. 200610086701.7 " a kind of GPS of utilization commutator pulse adjustment crystal oscillator frequency method of accuracy and system " and the patent No. 200710179291.5 has all proposed to utilize the scheme of GPS commutator pulse adjustment crystal oscillator frequency accuracy; Main thought is to utilize the GPS pulse per second (PPS) to detect the crystal oscillator frequency accuracy of final output; If any error; Be voltage control VCXO then through the D/A circuit conversion; The frequency of fine setting crystal, calibration crystal oscillator output frequency.The circuit of these schemes can only be exported fixing frequency signal, can not directly change the multiple stable high accuracy nominal frequency signal of output on demand; And these schemes are owing to adopt voltage control crystal oscillator; Through the method that the frequency signal close-loop feedback of final output is approached one by one; The repeated multiple times adjustment could be satisfied required precision; It is fast inadequately to regulate the speed, and is unfavorable for changing fast on demand the multiple stable high accuracy nominal frequency signal of output.
Summary of the invention
The utility model technical problem to be solved provides the apparatus for frequency synthesizing that a kind of GNSS of utilization pulse per second (PPS) is revised fast, can export multiple stable high accuracy nominal frequency signal on demand fast.
The utility model is to solve the problems of the technologies described above the technical scheme that adopts to provide the apparatus for frequency synthesizing that a kind of GNSS of utilization pulse per second (PPS) is revised fast; Comprise that GNSS receiver, crystal oscillator frequency detect and frequency synthesizer controls word counting circuit and Direct Digital Frequency Synthesizers (Direct Didital Frequency Synthesis is called for short DDS); Said crystal oscillator frequency detects and the clock end of frequency synthesizer controls word counting circuit links to each other with crystal oscillator; Input input nominal frequency value and link to each other with the GNSS receiver reception time service data and pulse per second (PPS), output link to each other with Direct Digital Frequency Synthesizers behind the output calibration the frequency synthesizer controls word and based on the clock of crystal oscillator.
The above-mentioned apparatus for frequency synthesizing that utilizes the GNSS pulse per second (PPS) to revise fast; Wherein, Said crystal oscillator frequency detects and frequency synthesizer controls word counting circuit comprises: pulse per second (PPS) validity testing circuit, pulse per second (PPS) rising edge testing circuit, counter and latch, frequency synthesizer controls word counting circuit, frequency synthesizer interface circuit and k frequency multiplier as a result, and their clock end all connects the input crystal oscillator frequency; Wherein, Said pulse per second (PPS) validity testing circuit input time service data; The output effective marker is to said frequency synthesizer controls word counting circuit; Said pulse per second (PPS) rising edge testing circuit input pulse per second (PPS), output are connected to counter and latch as a result, and said counter and latch output as a result are connected to frequency synthesizer controls word counting circuit; Said frequency synthesizer controls word counting circuit is imported the nominal frequency value simultaneously, and output is connected to frequency synthesizer interface circuit, frequency synthesizer interface circuit output frequency synthesizer control word; The output of k frequency multiplier links to each other with the input end of clock of Direct Digital Frequency Synthesizers and exports the clock based on crystal oscillator.
The above-mentioned apparatus for frequency synthesizing that utilizes the GNSS pulse per second (PPS) to revise fast, wherein, the input end of clock of said Direct Digital Frequency Synthesizers directly links to each other with the crystal oscillator output.
The above-mentioned apparatus for frequency synthesizing that utilizes the GNSS pulse per second (PPS) to revise fast, wherein, said crystal oscillator frequency detects and frequency synthesizer controls word counting circuit is made up of fpga chip able to programme.
The utility model contrast prior art has following beneficial effect: the crystal oscillator of the utility model is common crystal oscillator, without constant-temperature crystal oscillator or VCXO, has reduced the cost of equipment; Utilize the GNSS pulse per second (PPS) that the crystal oscillator frequency accuracy that offers DDS is detected; Directly provide the control word of revising the output of DDS frequency according to the error open loop; Rather than closed loop detects the frequency signal of the final output of feedback; Revise crystal oscillator frequency through D/A, its beneficial effect is that erection rate is fast, precision is high; Adopt the DDS output frequency signal, can change the multiple stable high accuracy nominal frequency signal of output on demand fast.
Description of drawings
Fig. 1 forms sketch map for the apparatus for frequency synthesizing that the utility model utilizes the GNSS pulse per second (PPS) to revise fast;
Fig. 2 is that crystal oscillator frequency detects and DDS control word counting circuit composition sketch map in the utility model apparatus for frequency synthesizing.
Among the figure:
1 GNSS receiver, 2 crystal oscillator frequencies detect and frequency synthesizer controls word counting circuit
3 Direct Digital Frequency Synthesizers, 4 crystal oscillators
21 pulse per second (PPS) validity testing circuits, 22 pulse per second (PPS) rising edge testing circuits
23 counters and latch 24 frequency synthesizer controls word counting circuits as a result
25 frequency synthesizer interface circuits, 26 k frequency multipliers
Embodiment
Below in conjunction with accompanying drawing and embodiment the utility model is done further to describe.
Fig. 1 forms sketch map for the apparatus for frequency synthesizing that the utility model utilizes the GNSS pulse per second (PPS) to revise fast.
See also Fig. 1; GNSS receiver 1 uses the GPS receiver in the present embodiment; GPS receiver output time service data and pulse per second (PPS) detect and frequency synthesizer controls word counting circuit 2 to crystal oscillator frequency; Simultaneously the required nominal frequency value in radio station also inputs to crystal oscillator frequency and detects and frequency synthesizer controls word counting circuit 2, can be by the radio station required nominal frequency value that is provided with of working.Crystal oscillator frequency detects and frequency synthesizer controls word counting circuit 2 output DDS frequency control words are controlled the required nominal frequency value in radio station that DDS output is revised through the GPS pulse per second (PPS) fast to Direct Digital Frequency Synthesizers 3 (DDS).Direct Digital Frequency Synthesizers 3 is a kind of IC-components through the direct control frequency synthesizer of digital interface output frequency, phase place, adopts AD9859 in the present embodiment.Crystal oscillator 4 detects to crystal oscillator frequency and frequency synthesizer controls word counting circuit 2 provides clock, is common crystal oscillator, need not adopt constant-temperature crystal oscillator or VCXO.Crystal oscillator frequency can be connected directly to the input end of clock of DDS chip and do frequency source.Adopt in the present embodiment crystal oscillator frequency through crystal oscillator frequency detect and frequency synthesizer controls word counting circuit 2 in k frequency multiplier 26 after in addition frequency multiplication drives, output does frequency source for DDS chip input end of clock based on the clock of crystal oscillator.K value 2.4576 in the present embodiment in the k frequency multiplier 26.
Crystal oscillator frequency detects and frequency synthesizer controls word counting circuit 2 is made up of fpga chip able to programme, sees also Fig. 2.GNSS time service data export pulse per second (PPS) validity testing circuit 21 to so that availability deciding is carried out in the GNSS pulse per second (PPS); When GNSS time service data are effective; Export effective marker to frequency synthesizer controls word counting circuit 24; To judge that this moment, the DDS frequency control word calculated effectively, can export frequency synthesizer interface circuit 25 to.The GNSS pps pulse per second signal exports pulse per second (PPS) rising edge testing circuit 22 to; Enable counter and latch 23 as a result when detecting the pulse per second (PPS) rising edge; To the crystal oscillator frequency counting, serve as to finish count signal with next GNSS pulse per second (PPS) rising edge, count value is crystal oscillator frequency.The method that counter can adopt repeatedly counting to get moving average reduces measure error.Frequency synthesizer controls word counting circuit 24 calculates according to nominal frequency value and crystal oscillator frequency count value, exports the DDS frequency control words to the DDS chip through frequency synthesizer interface circuit 25, thereby revises the output frequency of DDS.Crystal oscillator frequency is given circuit clock is provided, simultaneously through k frequency multiplier 26 in addition frequency multiplication with drive back output based on the clock of crystal oscillator to the DDS chip.
Because DDS chip incoming frequency source is crystal oscillator or is the clock based on crystal oscillator in source with it, so the error of its output frequency is relevant with the error of crystal oscillator.Counter and as a result latch 23 can be used for the error of DDS output frequency is revised in the crystal oscillator frequency count value that GNSS pps pulse per second signal accurately obtained under the cycle.The output nominal frequency of supposing expectation DDS is F0; Counter and as a result the actual crystal oscillator frequency that records of latch be Fc; Crystal oscillator frequency inputs to the DDS chip after k frequency multiplier frequency multiplication, DDS internal work clock is the N frequency multiplication of input clock, and then normalized frequency control word is:
FTW?=?2?*?PI?*?F0?/?(?Fc*k?*?N?)
Here 2 * PI represent one-period;
The bit wide of supposing the inner phase accumulator of DDS is W, and then actual frequency control word is:
FTW?=?round?(?2^W?*?F0?/?(?Fc?*k?*?N?))
Here round representes the division round numbers.
Obviously; Under the effective situation of GNSS time service data that receives, DDS output frequency per second can both obtain revising, and because the work characteristics of DDS chip; Its correction effect obtains embodying immediately on the DDS output frequency; Thereby obtained the beneficial effect that the direct erection rate of DDS output nominal frequency open loop is fast, precision is high, and the quick nominal frequency locking can realize starting shooting the time to expectation, in satisfying/the high frequency radio radio station is to the requirement of high accuracy and highly stable frequency.
Though the utility model discloses as above with preferred embodiment; Right its is not in order to limit the utility model; Any those skilled in the art; In spirit that does not break away from the utility model and scope, when can doing a little modification and perfect, so the protection range of the utility model is when being as the criterion with what claims defined.
Claims (4)
1. an apparatus for frequency synthesizing that utilizes the GNSS pulse per second (PPS) to revise fast is characterized in that, comprising: GNSS receiver (1), crystal oscillator frequency detect and frequency synthesizer controls word counting circuit (2) and Direct Digital Frequency Synthesizers (3); Said crystal oscillator frequency detects and the clock end of frequency synthesizer controls word counting circuit (2) links to each other with crystal oscillator (4); Input input nominal frequency value and link to each other with GNSS receiver (1) reception time service data and pulse per second (PPS), output link to each other with Direct Digital Frequency Synthesizers (3) behind the output calibration the frequency synthesizer controls word and based on the clock of crystal oscillator.
2. the apparatus for frequency synthesizing that utilizes the GNSS pulse per second (PPS) to revise fast as claimed in claim 1; It is characterized in that; Said crystal oscillator frequency detects and frequency synthesizer controls word counting circuit (2) comprising: pulse per second (PPS) validity testing circuit (21), pulse per second (PPS) rising edge testing circuit (22), counter and latch (23), frequency synthesizer controls word counting circuit (24), frequency synthesizer interface circuit (25) and k frequency multiplier (26) as a result, and their clock end all connects the input crystal oscillator frequency; Wherein, Said pulse per second (PPS) validity testing circuit (21) input time service data; The output effective marker is to said frequency synthesizer controls word counting circuit (24); Said pulse per second (PPS) rising edge testing circuit (22) input pulse per second (PPS), output are connected to counter and latch (23) as a result, and said counter and latch (23) output as a result are connected to frequency synthesizer controls word counting circuit (24); Said frequency synthesizer controls word counting circuit (24) is imported the nominal frequency value simultaneously, and output is connected to frequency synthesizer interface circuit (25), frequency synthesizer interface circuit (25) output frequency synthesizer control word; The input end of clock of the output of k frequency multiplier (26) and Direct Digital Frequency Synthesizers (3) links to each other and exports the clock based on crystal oscillator.
3. the apparatus for frequency synthesizing that utilizes the GNSS pulse per second (PPS) to revise fast as claimed in claim 1 is characterized in that the input end of clock of said Direct Digital Frequency Synthesizers (3) directly links to each other with crystal oscillator (4) output.
4. like claim 1 and the 2 described apparatus for frequency synthesizing that utilize the GNSS pulse per second (PPS) to revise fast, it is characterized in that said crystal oscillator frequency detects and frequency synthesizer controls word counting circuit (2) is made up of fpga chip able to programme.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201120234394U CN202150850U (en) | 2011-07-05 | 2011-07-05 | Frequency synthesizing device using GNSS second pulse for rapid modification |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201120234394U CN202150850U (en) | 2011-07-05 | 2011-07-05 | Frequency synthesizing device using GNSS second pulse for rapid modification |
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| CN202150850U true CN202150850U (en) | 2012-02-22 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201120234394U Expired - Lifetime CN202150850U (en) | 2011-07-05 | 2011-07-05 | Frequency synthesizing device using GNSS second pulse for rapid modification |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103281076A (en) * | 2013-05-28 | 2013-09-04 | 中国人民解放军63921部队 | Clock source and signal processing method thereof |
| CN103605138A (en) * | 2013-07-26 | 2014-02-26 | 成都海亨利科技有限公司 | Clock correction method and device for satellite navigation receiver |
| CN106027187A (en) * | 2016-04-29 | 2016-10-12 | 国家电网公司 | GPS (Global Positioning System) synchronizing signal frequency source circuit |
-
2011
- 2011-07-05 CN CN201120234394U patent/CN202150850U/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103281076A (en) * | 2013-05-28 | 2013-09-04 | 中国人民解放军63921部队 | Clock source and signal processing method thereof |
| CN103281076B (en) * | 2013-05-28 | 2016-04-13 | 中国人民解放军63921部队 | A kind of method of clock source and signal transacting thereof |
| CN103605138A (en) * | 2013-07-26 | 2014-02-26 | 成都海亨利科技有限公司 | Clock correction method and device for satellite navigation receiver |
| CN106027187A (en) * | 2016-04-29 | 2016-10-12 | 国家电网公司 | GPS (Global Positioning System) synchronizing signal frequency source circuit |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term |
Granted publication date: 20120222 |
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| CX01 | Expiry of patent term |