JP2725590B2 - Optical microwave unit for rubidium atomic oscillator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art A conventional optical microwave unit for a rubidium atomic oscillator has a cavity 1 as shown in FIG.
Has a microwave introduction antenna 4 and two microwave monitoring antennas 5 inside. The state of generation of microwaves inside the cavity 1 is directly monitored by the microwave monitoring antenna 5 to determine the tuning state of the cavity 1.

Here, copper having good thermal conductivity is used for the antenna 5 and its surface is plated with gold or silver so as to reduce microwave loss (for example,
60-59633).

[0004]

Since the conventional microwave unit has a large antenna shape, the mode of the microwave generated inside the cavity 1 is easily disturbed, and the half width Q of the frequency band as the cavity is easily reduced. There is a problem.

In view of the above drawbacks, an object of the present invention is to provide an optical microwave unit for a rubidium atomic oscillator that does not disturb the microwave inside the cavity and has a high frequency band and is stable.

[0006]

In order to eliminate the above-mentioned disadvantages, an optical microwave unit for a rubidium atomic oscillator according to the present invention irradiates an optical microwave to a cavity portion containing a rubidium gaucell and a rubidium gaucell. An optical microwave unit for a rubidium atomic oscillator equipped with a rubidium lamp, wherein at least 2
Antennas, and at least one of the antennas is constituted by a microstrip line.

[0007]

By forming the antenna inside the cavity with a microstrip line, an extra antenna line inside the cavity can be eliminated, and disturbance of the microwave mode can be suppressed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present description will be described in detail with reference to the drawings.

FIG. 1 shows the structure of an embodiment of an optical microwave unit for a rubidium atomic oscillator according to the present invention.
Inside the cavity 1, a rubidium gau cell 2, a solar cell 3, a microwave introducing antenna 4 and a microwave monitoring antenna 5 are provided. Here, the antenna 4 is for introducing microwaves irradiated from a rubidium lamp (not shown) into the cavity 1.
It is provided near a light incident hole 6 provided on the bottom surface of the cavity 1. On the other hand, the antenna 5 is for microwave monitoring, and is formed by a microstrip line on the same surface as the solar cell 3 on a printed board 9 arranged on the inner wall surface facing the light incident hole 6. . This microstrip line is formed of a copper thin film. The microwave monitoring antenna 5 is connected to the connector 6 outside the cavity 1, so that the state of generation of the microwave input by the microwave introduction antenna 4 inside the cavity 1 is directly monitored. The tuning state is accurately detected and determined.

FIG . 3 is a perspective view showing details of the cavity portion of the above-described embodiment. Light emitted from the rubidium lamp 7 is detected by the solar cell 3 through the light incident hole 6 and the rubidium gau cell 2, and is sent to an oscillation circuit (not shown) for processing. Here, the solar cell 3 and the oscillation circuit have the same configuration as the conventional configuration.

The present invention relates to an optical microwave unit of a rubidium atomic oscillator, wherein the microwave monitoring antenna 5 is formed by a microstrip line antenna.
Since the volume occupied by the antenna inside the cavity 1 can be reduced as compared with the conventional case, the microwave mode inside the cavity 1 is not disturbed. Therefore, the microwave generation state can be directly detected by the microwave monitoring antenna 5 without lowering the half width Q of the frequency band of the cavity 1, and the tuning state can be easily determined and adjusted.

The microstrip line constituting the microwave monitoring antenna 5 may be formed on a ceramic substrate or a Teflon substrate. The microstrip line itself may be a metal thin film, and can be formed of aluminum or the like in addition to copper.

[0013]

As described above, in the present invention, at least two antennas are provided inside the cavity of the optical microwave unit of the rubidium atomic oscillator, and the microwave monitoring antenna is formed by a microstrip line antenna. Therefore, the volume occupied by the antenna inside the cavity is reduced. Thereby, the disturbance of the mode generated inside the cavity due to the antenna is reduced, and the decrease in the half width Q of the frequency band of the cavity can be reduced. By reducing the decrease in the half width Q of the frequency band of the cavity, the S / N ratio of the output signal of the solar cell is improved, the characteristics of the rubidium atomic oscillator are stabilized, and the reliability is improved.

[Brief description of the drawings]

FIG. 1 is a structural diagram of an embodiment of an optical microwave unit for a rubidium atomic oscillator according to the present invention .

FIG. 2 is a structural view of an example of a conventional optical microwave unit for a rubidium atomic oscillator .

FIG. 3 is a partially cutaway perspective view showing details of a cavity portion of one embodiment of the optical microwave unit for a rubidium atomic oscillator of the present invention .

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cavity 2 ... Rubidium gaucell 3 ... Solar cell 4 ... Microwave introduction antenna 5 ... Microwave monitor antenna 6 ... Light entrance hole 7 ... Rubidium lamp 8 ... Connector 9 ... Printed board

Claims (7)

(57) [Claims] 1. A and rubidium lamp for irradiating light microwaves, and rubidium Gau cell the light microwave is irradiated, a rubidium atomic oscillator optical microwave unit with a cavity for containing the antenna , There is at least two antennas, and one antenna
Is the cavity into which the microwave is incident
The optical microwave provided near the light entrance hole is introduced.
The other antenna is a microphone for monitoring the microwave.
A microwave monitor antenna in front of the cavity
The micros provided on the bottom surface facing the light entrance hole.
An optical microwave unit for a rubidium atomic oscillator, comprising a trip line . 2. The optical microwave unit for a rubidium atomic oscillator according to claim 1 , wherein the microstrip line is formed on a printed circuit board. Wherein the microstrip line, according to claim 1, characterized in that it is formed on the ceramic substrate
An optical microwave unit for a rubidium atomic oscillator as described in the above. 4. The optical microwave unit for a rubidium atomic oscillator according to claim 1 , wherein the microstrip line is formed on a Teflon substrate. 5. The optical microwave unit for a rubidium atomic oscillator according to claim 1 , wherein the microstrip line is made of a metal thin film. 6. The optical microwave unit for a rubidium atomic oscillator according to claim 5 , wherein said microstrip line is made of a copper thin film. 7. The optical microwave unit for a rubidium atomic oscillator according to claim 5 , wherein said microstrip line is made of an aluminum thin film.