JPS5830238A - Cesium atom oscillator - Google Patents

Abstract

PURPOSE:To elevate stability, by stabilizing the oscillation frequency which has simply frequency-divided resonance frequency of a cesium atom, by a cesium atom resonator, and making frequency of an output voltage control type oscillator synchronize with said oscillation frequency. CONSTITUTION:The first voltage control type quartz oscillator 10 outputs oscillation frequency which has simply frequency-divided resonance frequency of a cesium atom. This oscillation frequency generates frequency being equal to the resonance frequency of a cesium atom through a multiplying device 11, and is inputted to a cesium atom resonator 6. By detecting its frequency difference, the oscillator 10 is stabilization-controlled. Also, an output of the second output voltage control type quartz oscillator 13 and an output of the oscillator 10 are inputted to mixer 12. An output of the oscillator 3 is inputted to a phase detector 15 through a multiplying frequency divider 14, and is phase-compared with a mixed output. In this way, the oscillator is synchronized with the oscillator 10, and an output is fetched.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cesium atomic oscillator, which has a simple division value of cesium atomic resonance frequency of 5.006880049891M.
Hz voltage-controlled crystal oscillator, stabilized by a frequency tube cesium atomic resonator, and synchronized with the frequency of the voltage-controlled crystal oscillator of another 5 MHz voltage-controlled crystal oscillator for output. Concerning a highly stable cesium atomic oscillator.

The atomic oscillator, which fully controls the crystal oscillator using the resonant frequency #jt of atoms and molecules as a reference, has extremely high long-term stability and is therefore used as a high-precision frequency generation source. In particular, cesium atomic oscillators are used as primary time standards.

The first diagram shows the configuration of a conventional cesium atomic oscillator.
Shown in the figure: 1 is a 5MHz voltage-controlled crystal oscillator, 2 is a 5MHz voltage-controlled crystal oscillator.
6 indicates a phase modulator, a 3-digit synthesizer, a 4-digit multiplier, a 5-digit mixed multiplier, 6 an atomic resonator, 7Fi low frequency oscillator, 8#-j phase detector, and a 9-digit selective amplifier tube.

This circuit creates a t-1r5MHz voltage-controlled crystal oscillator 1.
[The output of the low frequency oscillator 7 is used for phase modulation in the phase modulator 2, and the multiplier 4, mixer multiplier 5, and synthesizer 3 perform multiplication and mixing synthesis to generate a cesium atomic resonance frequency at, which is then combined with the atomic resonator 6. In addition, by comparing the phase of the output of the atomic resonator 6 and the output of the low frequency oscillator, the difference between the resonance frequency of the cesium atom and the input frequency t is detected from K, and the input frequency t is set to 5MHz so as to always match the resonance frequency of the cesium atom. The frequency of the voltage-controlled crystal oscillator 1 is controlled.

It is known that if the microwave spectrum input to the atomic resonator 6 is not uniform, the accuracy and stability of the cesium atomic oscillator will be impaired due to the influence of unnecessary spurious components. However, the resonance frequency of cesium atoms #IF
Since it is a fraction of i, conventionally, as shown in Fig. 1,
The frequency of the Hz voltage-controlled crystal oscillator 1 and the output frequency of the synthesizer 3 previously synthesized are mixed in the total mixing multiplier 5 to create the resonant frequency of the cesium atom, so a mixed tone occurs and is unnecessary. 5M HS voltage controlled crystal oscillator 1 with spurious
There were drawbacks that affected the frequency stability.

The purpose of the present invention is to solve the above-mentioned drawbacks by using a simple frequency division value of 5.006880049 of the cesium atomic resonance frequency.
It has an 891 MHz voltage-controlled crystal oscillator, which is stabilized by a cesium atomic resonator, and has a separate output voltage of 5
MHz voltage-controlled crystal oscillator frequency #! The object of the present invention is to provide a cesium atomic oscillator with extremely high F stability by synchronizing the frequency of the voltage controlled crystal oscillator.

In order to achieve the above object 1, the present invention provides a first voltage-controlled crystal oscillator Kurayoshi which outputs a signal tube with an oscillation frequency obtained by simply dividing the resonance frequency of the cesium atom in a cesium atomic oscillator circuit. What is the oscillation frequency of the voltage controlled crystal oscillator in No. 1? By simple multiplication to create a frequency at equal to the resonant frequency of a cesium atom, input it to a cesium atom resonator, compare it with the resonant frequency of the cesium atom, and detect the difference in frequency. Stabilizing and controlling the first voltage-controlled crystal oscillator, and mixing the output of the second voltage-controlled crystal oscillator for output with the output tube of the voltage-controlled crystal oscillator #w, 1;
By dividing and multiplying the mixed output and the second voltage-controlled crystal oscillator, the frequency created by 1V and the t phase are compared.
9. A cesium atomic oscillator specifically designed to synchronize the second voltage-controlled crystal oscillator with the first voltage-controlled crystal oscillator and output an output from the second voltage-controlled crystal oscillator? I decided to provide it.

Embodiments of the present invention will be explained below with reference to the drawings. Second
The figure is a block diagram of a cesium atomic oscillator according to an embodiment of the present invention, and those having the same functions as No. 11121 in the figure are designated by the same numbers. 10 is 5.006880049891
A MHz voltage-controlled crystal oscillator, 11 a multiplier, a 12-digit mixer, a 5-MHz voltage-controlled crystal oscillator for llj output, a 141j multiplier divider, and a 15-digit phase detector.

5.006880049891MHz voltage controlled crystal oscillation IFP10 output? By simply multiplying by the multiplier 11 and mixing it with other frequencies, an atomic resonance frequency AT is created.The phase modulation is performed at a low frequency using a method similar to the conventional method, and this is added to the atomic resonator 6 to read the low frequency voltage? The phase detector 8 detects the frequency difference between the resonance frequency of 19 cesium atoms and the input frequency #! #Voltage controlled crystal oscillator 10 to always match the resonant frequency of IvI-cesium atoms
T-control this? Highly stabilized.

In this method, 5.006880049891MHz'?
Since the microwave spectrum input to the Ki atomic resonator is simply multiplied and input to the atomic resonator 6, it is within ±5.00680049891 MHz of the atomic resonance frequency.Since Ktj spurious is likely to occur, it is 5.006880049891.
Highly stable operation with MHz voltage controlled crystal oscillator.

The output of the voltage controlled crystal oscillator 10 and the output of the 5 MHz voltage controlled crystal oscillator 13 for output? The mixer 12 mixes to create a frequency difference of 6.880049891KHz, and this voltage and the 5MHz voltage controlled crystal oscillator 1.
The frequency division/multiplying value (3451/
1366
Detects the difference in frequency with the voltage controlled crystal oscillator lO of 5.006880049891MHz, and outputs 5M
Hz voltage controlled crystal oscillator 13 is 5.00688004
Since it is controlled in synchronization with the 9891 MHz voltage controlled crystal oscillator 10, the output 5 MHz voltage controlled crystal oscillator 131r operates with high stability.

Therefore, a highly stable atomic oscillator can be constructed because it is not affected by unnecessary spurious signals. Note that 5 used in the present invention
, 006880049891MHz, a crystal oscillator with an integer multiple of this frequency may be used, and in a circuit to be compared with 5MHz for output, the frequency is divided to 5.
．． 006880049891MHz? All you have to do is get it.

The present invention has a voltage-controlled crystal oscillator with a simple branching frequency of 5.006880049891 MHz of the cesium atomic resonance frequency, and the cesium atomic resonance frequency can be obtained by simply multiplying this frequency without mixing it with other frequencies. In addition to the atomic resonator, there is frequency matching. Therefore, it is not affected by unnecessary spacing, so it is highly stable.
A crystal oscillator of 006880049891 MHz is obtained. On the other hand, the 5 MHz voltage-controlled crystal oscillator for output is synchronized with the above-mentioned crystal oscillator so that the output chip can be output, so that a highly stable cesium atomic oscillator system can be produced.

[Brief explanation of drawings]

Figure 1 is a block diagram of a conventional cesium atomic oscillator.
FIG. 2 is a block diagram of a cesium atomic oscillator according to an embodiment of the present invention. In the figure, 1.13 is a 5MHz voltage-controlled crystal oscillator, 2-digit phase modulator, 3 is a combiner, 4-, 11-digit multiplier, 5-digit mixed multiplier, 6Fi atomic resonator, 7Fi low-frequency oscillator, 8.1
! lj phase detector, 9 digit selection amplifier, 10 digit 5.006
880049891MHz voltage controlled crystal oscillator, 1
It is a 2Fi mixer and a 14-digit multiplier.

Claims (1)

[Claims] In the cesium atom oscillator circuit, the first circuit that simply divides the resonant frequency sound of the cesium atom and outputs a signal with a high oscillation frequency.
a voltage-controlled crystal oscillator, the oscillation frequency of the first voltage-controlled crystal oscillator is simply multiplied, and a frequency t-f ¥9, which is equal to the resonance frequency of cesium atoms, is input to the cesium atomic resonator; Compared to the resonance frequency of the nuclear cesium atom,
The first voltage-controlled crystal oscillator is stabilized and controlled by C and K, which detect the difference in frequency, and the output of the second voltage-controlled crystal oscillator for output and the first voltage-controlled crystal oscillator are controlled to stabilize the first voltage-controlled crystal oscillator. output? By comparing the frequency and i phase of the mixed output and the second voltage controlled crystal oscillator by dividing and multiplying the mixed output and the second voltage controlled crystal oscillator,
A cesium atomic oscillator characterized in that the output voltage is output from the second voltage-controlled crystal oscillator in synchronization with the second voltage-controlled crystal oscillator.