JPH04257119A - Rubidium atom oscillator - Google Patents

Abstract

PURPOSE:To reduce the number of adjustment positions and the power consumption by eliminating a need of multiplying diodes and matching devices. CONSTITUTION:This device consists of a voltage controlled crystal oscillator 1 which is controlled by the error signal from an optical microwave resonance part 3 and outputs a highly stable frequency and a mixer 9, and this mixer 9 obtains 680MHz and 53125MHz from a voltage controlled oscillator 6, for which a PLO consists of the voltage controlled crystal oscillator 1, frequency dividers 4, 10, 11, and 12, a phase comparator 8, and a low-pass filter 5, and a synthesizer 7 respectively to generate a signal required for the optical microwave resonance part 3.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an atomic oscillator, and more particularly to a rubidium atomic oscillator using an optical pumping method.

0002

[Prior Art] As shown in FIG. 2, a conventional rubidium atomic oscillator includes a voltage controlled crystal oscillator 1 and a 5.3125MH
z, a mixer 9 that mixes the output from the synthesizer 7 and the output of the voltage controlled crystal oscillator 1, and a multiplier diode 14 that multiplies this signal to a higher order.
, a matching box 13 capable of adjusting impedance in order to operate the multiplier diode 14 , an optical microwave resonator 3 to which the signal multiplied by the multiplier diode 14 is supplied, and an optical microwave resonator 3 . and a frequency controller 2 that controls a voltage-controlled crystal oscillator 1 using an output signal from the oscillator.

With the configuration shown in FIG. 2, for example, 6
When a 0MHz voltage-controlled crystal oscillator 1 is used, a mixer 9 mixes 5.3125MHz from the synthesizer 7 and 60MHz from the voltage-controlled crystal oscillator 1, and performs impedance matching and bias adjustment to operate the multiplier diode 14. By performing this in the matching box 13, the 6.8346875 GHz required for the optical microwave resonance section 3 was generated by the high-order multiplication diode 14, thereby operating the rubidium atomic oscillator.

0004

[Problems to be Solved by the Invention] In the case of the conventional rubidium atomic oscillator described above, since the multiplication order of the multiplication diode is large, it is necessary to greatly amplify the output signal of the voltage controlled crystal oscillator and supply it to the multiplication diode. This resulted in low efficiency and high power consumption. In addition, it takes time to adjust bias and impedance matching in order to operate the multiplier diode, and the circuit configuration becomes complicated, making it difficult to reduce the size and cost. Therefore, an object of the present invention is to reduce the number of adjustment points and reduce power consumption of a rubidium atomic oscillator.

[0005]

[Means for Solving the Problems] According to the present invention, there is provided a voltage controlled crystal oscillator that generates an output signal of a rubidium atomic oscillator, and a frequency divider for the voltage controlled crystal oscillator that divides the frequency of the output signal of the voltage controlled crystal oscillator. and a signal from a voltage controlled oscillator frequency divider that divides the output signal of the voltage controlled oscillator that oscillates at a first frequency. a low-pass filter that converts the difference into a DC voltage with a predetermined loop constant; the voltage-controlled oscillator controlled by the DC voltage signal; a synthesizer that generates a second frequency signal from the voltage-controlled crystal oscillator; and an output of the synthesizer. and an output signal of the voltage controlled oscillator, an optical microwave resonator to which the output signal from the mixer is supplied, and an output signal from the optical microwave resonator to generate the voltage controlled crystal oscillator. A rubidium atomic oscillator is obtained, characterized in that it has a frequency controller that controls.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings. FIG. 1 is a block diagram of a rubidium atomic oscillator according to an embodiment of the present invention. The rubidium atomic oscillator of this embodiment includes a voltage controlled crystal oscillator 1 that generates an output signal of the rubidium atomic oscillator, a voltage controlled oscillator 6 that oscillates at 6840 MHz (first frequency), and an output signal of the voltage controlled crystal oscillator 1. a frequency divider 4 for the voltage-controlled crystal oscillator 1 to divide the frequency;
Frequency dividers 10, 11, 12 for the voltage controlled oscillator 6 that frequency divides the output signal of the voltage controlled oscillator 6, and a signal from the frequency divider 4 for the voltage controlled crystal oscillator 1 and frequency division for the voltage controlled oscillator 6. A phase comparator 8 compares the phases of the signals from the devices 10, 11, and 12, and a phase comparator 8 converts the difference in phase comparison into a DC voltage with a predetermined loop constant, and the voltage controlled oscillator 6 is activated by the DC voltage. 5.3125 MHz (second frequency) from the controlled low-pass filter 5 and the voltage controlled crystal oscillator 1
Synthesizer 7 that produces signals and Synthesizer 7
a mixer 9 that mixes the output signal of the voltage controlled oscillator 6 with the output signal of the voltage controlled oscillator 6; an optical microwave resonator 3 that is supplied with the output signal from the mixer 9; Frequency controller 2 that controls the controlled crystal oscillator 1
It is characterized by having the following.

The output from the voltage controlled crystal oscillator 1 is converted into a 5.3125 MHz signal by the synthesizer 7 and converted into a 6840 MHz signal by the mixer 9 from the voltage controlled oscillator 6.
z and supplied to the optical microwave resonator 3. The optical microwave resonator 3 generates an error signal using the applied microwave and supplies it to the frequency controller 2. The frequency controller 2 transmits the error signal from the optical microwave resonator 3 to the voltage controlled crystal oscillator 1. is converted into a control voltage. As a result, the output frequency of the voltage-controlled crystal oscillator 1 becomes highly stable as it becomes equal to the frequency stability of the optical microwave resonance section 3. On the other hand, the signal from the voltage controlled oscillator 6 is transmitted to the frequency divider 10
, a frequency divider 11, and a frequency divider 12, and the signal from the voltage controlled crystal oscillator 1 is frequency-divided by a frequency divider 4. The signals frequency-divided by the frequency dividers 10, 11, and 12 and the signal frequency-divided by the frequency divider 4 are connected to a phase comparator 8.
The phase can be compared by For example, the frequency of voltage controlled crystal oscillator 1 is set to 10 MHz, and the prescalers of frequency divider 4 and frequency divider 10 are set to 1/16 and 1/64, respectively.
Then, the phase comparison frequency is 0.625MHz, and by combining the low-pass filter 5 that converts the difference at the time of phase comparison into a DC voltage with a predetermined loop constant, the voltage controlled oscillator 6 adjusts the frequency stability of the voltage controlled crystal oscillator 1. is equivalent to That is, the output frequency of the voltage controlled oscillator 6 is also equivalent to the frequency stability of the optical microwave resonance section, and a highly stable rubidium atomic oscillator can be constructed.

[0008]

As explained above, the present invention has a configuration in which the microwave supplied to the optical microwave resonance section is obtained by mixing the output of the voltage controlled oscillator and the signal from the synthesizer. No need for multiplier diodes and matching boxes to generate waves,
Since the number of adjustment points can be significantly reduced, an inexpensive rubidium atomic oscillator can be provided. Furthermore, since no multiplier diode is used, signal efficiency relative to power consumption can be significantly improved, resulting in lower power consumption.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a rubidium atomic oscillator according to an embodiment of the present invention.

FIG. 2 is a block diagram of a conventional rubidium atomic oscillator.

[Explanation of symbols]

1 Voltage controlled crystal oscillator 2 Frequency controller 3. Optical microwave resonance part 4 Frequency divider 5 Low pass filter 6 Voltage controlled oscillator 7 Synthesizer 8 Phase comparator 9 Mixer 10 Frequency divider 11 Frequency divider 12 Frequency divider

Claims (2)

[Claims] 1. A voltage controlled crystal oscillator that generates an output signal of a rubidium atomic oscillator, and a signal from a voltage controlled crystal oscillator frequency divider that frequency divides the output signal of the voltage controlled crystal oscillator, and oscillates at a first frequency. A phase comparator that compares the phase of the output signal of the voltage controlled oscillator with the signal from the frequency divider for the voltage controlled oscillator, and the phase comparator converts the difference at the time of phase comparison into a DC voltage with a predetermined loop constant. the voltage controlled oscillator controlled by the DC voltage signal; a synthesizer that generates a second frequency signal from the voltage controlled crystal oscillator; and an output signal of the synthesizer and the output signal of the voltage controlled oscillator. A mixer for mixing, an optical microwave resonator to which an output signal from the mixer is supplied, and a frequency controller for controlling the voltage-controlled crystal oscillator by the output signal from the optical microwave resonator. A rubidium atomic oscillator featuring Claim 2: The first frequency is 6840MHz.
The rubidium atomic oscillator according to claim 1, wherein the second frequency is 5.3125 MHz.