JPH089926Y2 - Dielectric resonator oscillator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a dielectric resonator oscillator in which an oscillation circuit is incorporated in a dielectric resonator.

[Background Art] An oscillator using a TEM mode dielectric resonator, a TM ₀₁₀ mode dielectric resonator, a TE _01δ mode dielectric resonator, or the like has been put into practical use. However, the oscillator using the dielectric resonator of any mode has an outer shape larger than that of the original dielectric resonator because the oscillator circuit is provided outside the dielectric resonator.

In addition, Table 1 roughly compares the sizes of the Q and external dimensions of the conventional TEM mode dielectric resonator oscillator, TM ₀₁₀ mode dielectric resonator oscillator, and TE _{01 δ} mode dielectric resonator oscillator. It was done.

Of these, the TEM mode dielectric resonator oscillator is the smallest, but has a small Q, and therefore has a disadvantage that the CN ratio (carrier noise ratio) is small especially at a high frequency of 3 GHz or higher. On the other hand, although the TE _{01 δ-} mode dielectric resonator oscillator had a good CN ratio, it had the largest external dimensions when the oscillator was constructed. On the other hand, in the TM ₀₁₀ mode dielectric resonator oscillator, both Q and external dimensions are located in the middle.

[Problems to be Solved by the Invention] The present invention has been made in view of the above background art, and its purpose is to reduce the size of a TM ₀₁₀ mode dielectric resonator oscillator. The object is to provide a dielectric resonator oscillator that is small and has a good CN ratio.

[Means for Solving the Problems] Therefore, the dielectric resonator oscillator of the present invention is characterized in that the oscillation circuit is mounted in the cavity formed around the dielectric post in the TM ₀₁₀ mode dielectric resonator. I am trying.

In the [Operation] The present invention, an oscillation circuit provided outside the dielectric resonators conventionally, since was incorporated within the TM ₀₁₀ mode dielectric resonator, the TM ₀₁₀ mode dielectric resonator The external dimensions could be reduced. Further, since the TM ₀₁₀ mode dielectric resonator has a good CN ratio, the present invention has made it possible to obtain a smaller TM ₀₁₀ mode dielectric resonator having a good CN ratio.

The configuration of the present invention can be applied to a TE _{01 δ} mode dielectric resonator oscillator, but since the TE _{01 δ} mode dielectric resonator itself is large, the merit of miniaturization by incorporating an oscillation circuit was small. In addition, since the TEM mode dielectric resonator has a structure in which the entire resonator is filled with a dielectric, there is no space for incorporating the oscillation circuit, and the oscillation circuit cannot be mounted inside.

[Embodiment] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 and 2 show an embodiment of the present invention. In this embodiment, a pillar-shaped ceramic dielectric post 2 is erected in the center of the metal case 5 for TM.
_{The 010-} mode dielectric resonator 1a is configured, and the upper and lower surfaces of the dielectric post 2 are joined to the inner surface of the metal case 5 by the electrode film 6 formed by applying and baking a conductive paste such as silver paste. There is. Also, this metal case 5
A power supply terminal 7 and an output terminal 8 are attached to the.
On the side where the power supply terminal 7 and the output terminal 8 are provided, a ceramic dielectric substrate 9 is provided at the bottom of the cavity 3 formed around the dielectric post 2, and the dielectric substrate 9 is provided. An oscillator circuit 4 composed of an integrated circuit or the like is mounted on the surface of 9 and the oscillator circuit 4, the internal electromagnetic field, the power supply terminal 7 and the output terminal 8 are formed on the surface of a dielectric substrate 9 by a microstrip. They are connected by a connecting circuit 10 such as a line. Therefore, if the TM ₀₁₀ mode dielectric resonator oscillator 11 has the above structure,
The external dimensions are not larger than those of the _TM010 mode dielectric resonator 1a, and the size can be reduced as compared with the conventional one in which the oscillation circuit 4 is provided outside.

What is shown in FIGS. 3 and 4 is another example of the present invention. In this embodiment, the ceramic dielectric post 2 is integrally molded in the center of the ceramic case 12 which is open on both sides, and a conductive paste such as silver paste is applied and baked on the entire outer surface of the ceramic case 12 to form the electrode film 13. And a metal cover 14 is attached to both side surfaces of the ceramic case 12 to form the TM ₀₁₀ mode dielectric resonator 1b. Then, in the ceramic case 12, the power supply terminal 7 and the output terminal 8
The oscillator circuit 4 is mounted directly on the inner bottom surface 15 of the ceramic case 12 in the cavity 3 between the dielectric post 2 and the ceramic case 12, and the oscillator circuit 4, the internal electromagnetic field, the power supply terminal 7 and the output terminal 8 are mounted. A coupling circuit such as a microstrip line wired inside the ceramic case 12
Combined by 10. In the TM ₀₁₀ mode dielectric resonator oscillator 16 of this embodiment, since the ceramic case 12 is used, there is no difference in the coefficient of thermal expansion between the ceramic case 12 and the dielectric post 2 and the temperature stability is improved. It improves and the CN ratio becomes even better.

A ceramic case and a dielectric post are formed using a ceramic material having a relative dielectric constant ε _r = 38, and a TM ₀₁₀ mode dielectric resonator oscillator (Example A) for the 3 GHz band is manufactured. The volume ratio and the CN ratio were compared with a 3 GHz band TEM mode dielectric resonator oscillator (conventional example B) in which a dielectric post was formed of a ceramic material having a relative dielectric constant ε _r = 38.
Table 2 shows an example of this result.

Therefore, it was possible to fabricate a TM ₀₁₀ mode dielectric resonator oscillator having a good CN ratio, which is slightly larger than the conventionally known TEM mode dielectric resonator oscillator.

[Effects of the Invention] According to the present invention, the TM ₀₁₀ mode dielectric resonator oscillator can be downsized, and a small dielectric resonator oscillator with a good CN ratio can be realized.

In the present specification, the electromagnetic field mode called the TM ₀₁₀ mode is used in the cylindrical coordinate system, so it may be called by another name for the way of taking the coordinates.

[Brief description of drawings]

1 is a plan sectional view showing an embodiment of the present invention, FIG. 2 is a sectional view taken along line XX of FIG. 1, and FIG. 3 is a plan sectional view showing another embodiment of the present invention. The drawing is a sectional view taken along line YY of FIG. 1a, 1b …… TM ₀₁₀ mode dielectric resonator 2 …… Dielectric post 3 …… Cavity 4 …… Oscillation circuit

Claims (1)

[Scope of utility model registration request] 1. A dielectric resonator oscillator in which an oscillating circuit is mounted in a cavity formed around a dielectric post in a TM ₀₁₀ mode dielectric resonator.