CN203086445U - Novel microwave atomic clock system - Google Patents

Abstract

The utility model discloses a novel microwave atomic clock system which is characterized in that: the novel microwave atomic clock system comprises a first atom frequency marking unit, a second atom frequency marking unit, a frequency mixing unit, a filtering unit, a counting unit and a DDS correction unit; the first atom frequency marking unit is successively connected with the counting unit and the frequency mixing unit; the second atom frequency marking unit is successively connected with the counting unit and the DDS correction unit; the frequency mixing unit is successively connected with the DDS correction unit and the filtering unit; and the counting unit is connected with the DDS correction unit; wherein, the counting unit performs frequency counting on the first atom frequency marking unit for obtaining a frequency value M, and performs frequency counting on the second atom frequency marking unit for obtaining a frequency value N. The DDS correction unit corrects the value relationship between M and N under reference clock of the second atom frequency marking unit and transmits the corrected M and N to the frequency mixing unit, and furthermore transmits to the filtering unit. The novel microwave atomic clock system realizes output frequency signal output when external factors are changed.

Description

A kind of novel microwave atomic clock system

Technical field

The utility model belongs to the atomic frequency standard technical field, particularly a kind of novel microwave atomic clock system.

Background technology

The disjunction mark standard had been widely used in numerous areas when atomic frequency standard was exported as one with its stable frequency values, but the variation of operating ambient temperature, can cause fatal influence to atomic frequency standard internal physical system and electronic circuit, finally cause the instability of atomic frequency standard complete machine output signal frequency.People overcome the influence of this respect by many methods in this respect: for example atomic frequency standard is placed under the isoperibol and works, or the unsettled influence of output signal frequency value that comes compensates to cause by inner parameter.

The utility model content

Technical problem to be solved in the utility model is itself to start with from the atomic frequency standard system design, and a kind of novel microwave atomic clock system that can realize the outputting stable frequency signal when extraneous factor changes is provided.

For solving the problems of the technologies described above, the utility model provides a kind of novel microwave atomic clock system, comprising: the first atomic frequency standard unit, the second atomic frequency standard unit, mixing unit, filter unit, counting unit and DDS amending unit.The described first atomic frequency standard unit is connected with described counting unit, described mixing unit successively; The described second atomic frequency standard unit is connected with described counting unit, described DDS amending unit successively; Described mixing unit is connected with described DDS amending unit, filter unit successively; Described counting unit is connected with described DDS amending unit.Further, described DDS amending unit comprises: central processing unit, DDS chip; Described central processing unit is connected with described counting unit, described DDS chip successively; Described DDS chip is connected with the described second atomic frequency standard unit, described mixing unit successively.

Further, the described first atomic frequency standard unit, the described second atomic frequency standard unit have identical temperature coefficient.

Further, the short-term frequency stability of the described first atomic frequency standard unit is better than the short-term frequency stability of the described second atomic frequency standard unit.

Further, the long-term frequency stability of the described first atomic frequency standard unit are better than the long-term frequency stability of the described second atomic frequency standard unit.

Further, through the revised M of described DDS amending unit, N numerical relation be: M=2N.

Further, described counting unit is to walk hour counter.

Further, described mixing unit is a frequency mixer.

Further, described filter unit is a filter.

A kind of novel microwave atomic clock system that the utility model provides is characterized in that, comprising: the first atomic frequency standard unit, the second atomic frequency standard unit, mixing unit, filter unit, counting unit and DDS amending unit.The first atomic frequency standard unit is connected with counting unit, mixing unit successively; The second atomic frequency standard unit is connected with counting unit, DDS amending unit successively; The mixing unit is connected with DDS amending unit, filter unit successively; Counting unit is connected with the DDS amending unit.Wherein, counting unit is carried out frequency counting to the first atomic frequency standard unit and is obtained frequency values M under the reference clock of the first atomic frequency standard unit, the second atomic frequency standard unit is carried out frequency counting obtain frequency values N; The DDS amending unit is revised described M, N numerical relation under the reference clock of the second atomic frequency standard unit and revised M, N is transferred to the mixing unit; And then transfer to filter unit.The utility model has been realized still exporting stable frequency signal when extraneous factor changes.Simultaneously, the utlity model has characteristics simple in structure, easy to operate, that accuracy is high.

Description of drawings

A kind of novel microwave atomic clock system theory structure block diagram that Fig. 1 provides for the utility model embodiment.

Wherein, the 201-first atomic frequency standard unit, the 202-second atomic frequency standard unit, 203-mixing unit, 204-filter unit, 205-counting unit, 206-DDS amending unit.

Embodiment

Below in conjunction with accompanying drawing, the embodiment that the utility model is provided is described in further detail.

Referring to Fig. 1, a kind of novel microwave atomic clock system that the utility model embodiment provides comprises: the first atomic frequency standard unit 201, the second atomic frequency standard unit 202, mixing unit 203, filter unit 204, counting unit 205 and DDS amending unit 206.Wherein, the first atomic frequency standard unit 201 is connected with counting unit 205, mixing unit 203 successively.The second atomic frequency standard unit 202 is connected with counting unit 205, DDS amending unit 206 successively.Mixing unit 203 is connected with DDS amending unit 206, filter unit 204 successively.Counting unit 205 is connected with DDS amending unit 206.

In the present embodiment, counting unit 205 is carried out frequency counting to the first atomic frequency standard unit 201 and is obtained frequency values M under the reference clock of the first atomic frequency standard unit 201, simultaneously the second atomic frequency standard unit 202 is carried out frequency counting and obtain frequency values N.DDS amending unit 206 is revised M, N numerical relation under the reference clock of the second atomic frequency standard unit 202.DDS amending unit 206 transfers to mixing unit 203 with revised M, N and carries out Frequency mixing processing.Mixing unit 203 transfers to filter unit 204 with the frequency value F that obtains after the Frequency mixing processing and carries out Filtering Processing.Signal after filter unit 204 Filtering Processing output the most at last.

In the present embodiment, DDS amending unit 206 comprises: central processing unit, DDS chip.Wherein, central processing unit is connected with counting unit 205, DDS chip successively, is used for deciding the size of correction value and delivering to the frequency register of DDS chip internal according to the frequency values that obtains M, N from counting unit.The DDS chip is connected with the second atomic frequency standard unit 202, mixing unit 203 successively, be used under the reference clock of the second atomic frequency standard unit 202, according to the correction value that central processing unit determined DDS chip internal frequency register value is revised, and then exported suitable frequency signal and 203 carry out Frequency mixing processing to the mixing unit.

In the present embodiment, the first atomic frequency standard unit 201, the second atomic frequency standard unit 202 have identical temperature coefficient.Be that the complete machine output signal frequency changing value size and Orientation that causes of external working environment variation of temperature is all identical.Simultaneously, the first atomic frequency standard unit 201 other performance except that temperature performance is better than the second atomic frequency standard unit 202.

Preferably, the short-term frequency stability of the first atomic frequency standard unit 201 is better than the short-term frequency stability of the second atomic frequency standard unit 202.

Preferably, the long-term frequency stability of the first atomic frequency standard unit 201 are better than the long-term frequency stability of the second atomic frequency standard unit 202.

In the present embodiment, through DDS amending unit 206 revised M, N numerical relation be: M=2N.Concrete operation method is as M=20.000000MHz before revising, and the decimal place of N=10.001000MHz(M, N is relevant with DDS chip figure place, and for example there are 48 bit frequency registers its inside of AD9852, and its frequency resolution can reach 2 ⁴⁸, for the frequency signal of 10MHz, distinguishable is 3.6 * 10 ^-8Hz).Requiring M in the present embodiment is 2 times of N, therefore central processing unit is under the prerequisite of access count unit 205 M that obtains, N value, send concrete correction value to the DDS chip, making it at the second atomic frequency standard unit, 202 output frequency signal N(10.001000MHz) frequency signal of revising back frequency values N '=10.000000MHz with reference to following output is to mixing unit 203, is 2 times of N to guarantee in the mixing unit 203 M of place.

Preferably, mixing unit 203 is frequency mixers.

Preferably, filter unit 204 is filters.

Preferably, counting unit 205 is to walk hour counter.

Below by theory analysis, prove that a kind of novel microwave atomic clock system that the utility model embodiment provides when extraneous factor changes can realize the output frequency value stabilization.

Analytical proof:

In a kind of novel microwave atomic clock system that present embodiment provides, establish:

$F_1=F_{01}(1+\frac{\mathrm{\Δ}{F}_1}{F_{01}})=F_{01}(1+v_1)\→\left(1\right)$

$F_2=F_{02}(1+\frac{\mathrm{\Δ}{F}_2}{F_{02}})=F_{02}(1+v_2)\→\left(2\right)$

$F_3=F_{03}(1+\frac{\mathrm{\Δ}{F}_3}{F_{03}})=F_{03}(1+v_3)\→\left(3\right)$

Wherein, F ₁, F ₂, F ₃It is respectively the frequency values of the first atomic frequency standard unit 201, the second atomic frequency standard unit 202,203 outputs of mixing unit; F ₀₁, F ₀₂, F ₀₃It is respectively the frequency initial value of the first atomic frequency standard unit 201 behind the system stability, the second atomic frequency standard unit 202,203 outputs of mixing unit; v ₁, v ₂, v ₃It is respectively the relative average frequency deviation of the first atomic frequency standard unit 201, the second atomic frequency standard unit 202, mixing unit 203.

Get by formula (3):

$v_3=\frac{F_3}{F_{03}}-1=\frac{F_1-F_2}{F_{03}}-1\→\left(4\right)$

1, when the operating ambient temperature T of the first atomic frequency standard unit 201, the second atomic frequency standard unit 202 changes, will cause F ₁=F ₀₁+ Δ F ₁, F ₂=F ₀₂+ Δ F ₂, because the utility model embodiment is the first atomic frequency standard unit 201, the second atomic frequency standard unit of selecting 202 with uniform temp coefficient, therefore: Δ F ₁=Δ F ₂, substitution formula (4):

$v_3=\frac{(F_{01}+\mathrm{\Δ}{F}_1)-(F_{02}+\mathrm{\Δ}{F}_2)}{F_{03}}-1=\frac{F_{01}-F_{02}}{F_{03}}-1\→\left(5\right)$

In the present embodiment,, F is arranged owing to be mixer action ₀₃=F ₀₁-F ₀₂So, the relative average frequency deviation v of formula (5) ₃=0, the temperature coefficient identical first atomic frequency standard unit 201, the second atomic frequency standard unit 202 are selected in this explanation for use, when the frequency signal of acquisition is when variations in temperature after mixing unit 203 acts on, can't influence the output frequency of system, reach the purpose that improves stability.

2, when the output frequency of the first atomic frequency standard unit 201 that other factors (except that temperature) causes, the second atomic frequency standard unit 202 changes, because the performance of the first atomic frequency standard unit 201 is better than the second atomic frequency standard unit 202(is better than the second atomic frequency standard unit 202 as the short-term frequency stability of the first atomic frequency standard unit 201 short-term frequency stability in the present embodiment, the long-term frequency stability of the first atomic frequency standard unit 201 are better than the long-term frequency stability of the second atomic frequency standard unit 202), so the v in the assumption (1) ₁With respect to v ₂, can ignore, so can get by formula (4):

$v_3=\frac{F_{01}-F_{02}(1+v_2)}{F_{03}}-1=\frac{(F_{01}-F_{02})-F_{02}{v}_2}{F_{03}}-1=-\frac{F_{02}}{F_{03}}{v}_2\→\left(6\right)$

At this moment, present embodiment obtains F by DDS amending unit 206 ₀₁=2F ₀₂Thereby, F ₀₃=F ₀₁-F ₀₂=F ₀₂, so formula (6) becomes:

v ₃＝-v ₂→(7)

The relative average frequency deviation that can reflect the second atomic frequency standard unit 202 by formula (7) as can be known by the relative average frequency deviation of mixing unit 203 processing back whole systems, the conclusion of convolution (5) acquisition has simultaneously proved that a kind of novel microwave atomic clock system that the utility model embodiment provides when extraneous factor changes can realize the outputting stable frequency signal.

In actual applications, when external environment changes (as temperature), according to tradition atomic frequency standard system independently, therefore its output signal frequency stability will be and influenced, but the differential type structure of the present invention's design, the signal frequency stability of frequency mixing module output can reflect the signal frequency stability of original independently atomic frequency standard system, and not changed by external environment and influence.

A kind of novel microwave atomic clock system that the utility model provides is characterized in that, comprising: the first atomic frequency standard unit 201, the second atomic frequency standard unit 202, mixing unit 203, filter unit 204, counting unit 205 and DDS amending unit 206.The first atomic frequency standard unit 201 is connected with counting unit 205, mixing unit 203 successively; The second atomic frequency standard unit 202 is connected with counting unit 205, DDS amending unit 206 successively; Mixing unit 203 is connected with DDS amending unit 206, filter unit 204 successively; Counting unit 205 is connected with DDS amending unit 206.Wherein, counting unit 205 is carried out frequency counting to the first atomic frequency standard unit 201 and is obtained frequency values M under the reference clock of the first atomic frequency standard unit 201, the second atomic frequency standard unit 202 is carried out frequency counting obtain frequency values N; DDS amending unit 206 is revised M, N numerical relation under the reference clock of the second atomic frequency standard unit 202 and revised M, N is transferred to mixing unit 203; And then transfer to filter unit 204.The utility model has been realized still exporting stable frequency signal when extraneous factor changes.Simultaneously, the utlity model has characteristics simple in structure, easy to operate, that accuracy is high.

It should be noted last that, above embodiment is only unrestricted in order to the explanation the technical solution of the utility model, although the utility model is had been described in detail with reference to example, those of ordinary skill in the art is to be understood that, can make amendment or be equal to replacement the technical solution of the utility model, and not breaking away from the spirit and scope of technical solutions of the utility model, it all should be encompassed in the middle of the claim scope of the present utility model.

Claims (9)

1. a novel microwave atomic clock system is characterized in that, comprising: the first atomic frequency standard unit, the second atomic frequency standard unit, mixing unit, filter unit, counting unit and DDS amending unit;

The described first atomic frequency standard unit is connected with described counting unit, described mixing unit successively;

The described second atomic frequency standard unit is connected with described counting unit, described DDS amending unit successively;

Described mixing unit is connected with described DDS amending unit, filter unit successively;

Described counting unit is connected with described DDS amending unit.

2. according to the described novel microwave atomic clock system of claim 1, it is characterized in that described DDS amending unit comprises: central processing unit, DDS chip;

Described central processing unit is connected with described counting unit, described DDS chip successively;

Described DDS chip is connected with the described second atomic frequency standard unit, described mixing unit successively.

3. according to the described novel microwave atomic clock system of claim 2, it is characterized in that:

The described first atomic frequency standard unit, the described second atomic frequency standard unit have identical temperature coefficient.

4. according to the described novel microwave atomic clock system of claim 3, it is characterized in that:

The short-term frequency stability of the described first atomic frequency standard unit is better than the short-term frequency stability of the described second atomic frequency standard unit.

5. according to the described novel microwave atomic clock system of claim 3, it is characterized in that:

The long-term frequency stability of the described first atomic frequency standard unit are better than the long-term frequency stability of the described second atomic frequency standard unit.

6. according to each described novel microwave atomic clock system of claim 1-5, it is characterized in that:

Through the revised M of described DDS amending unit, N numerical relation be: M=2N.

7. according to the described novel microwave atomic clock system of claim 6, it is characterized in that:

Described counting unit is to walk hour counter.

8. according to the described novel microwave atomic clock system of claim 7, it is characterized in that:

Described mixing unit is a frequency mixer.

9. described according to Claim 8 novel microwave atomic clock system is characterized in that:

Described filter unit is a filter.

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