JPH0466121B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a dielectric resonator device that utilizes resonance of TM ₁₁₀ mode (hereinafter simply referred to as TM ₁₁₀ mode) in a rectangular cavity.

(Prior art and its problems) As a filter using TM ₁₁₀ mode,
There is one known in Japanese Patent No. 53-119650. In such a filter, a necessary number of stages are combined to form a single stage resonator, each of which has a linear cylindrical or prismatic dielectric inside a case that functions as a shielding case.

This has limited the ability to meet the eternal demands of the telecommunications equipment industry for miniaturization and lower prices.

(Object of the Invention) Therefore, an object of the present invention is to provide a small and low-cost dielectric resonator device for use in, for example, a filter.

(Means for Solving the Problems) In order to achieve the above object, the present invention integrates three columnar dielectrics in a rectangular parallelepiped cavity shielding case in a state perpendicular to each other. The axial direction of one of the columnar dielectrics is Z
A dielectric resonator that utilizes TM ₁₁₀ mode resonance, TM ₀₁₁ mode resonance, and TM ₁₀₁ mode resonance in a rectangular coordinate system aligned with the axis, and an external coupling means for coupling this dielectric resonator to an external circuit. In the dielectric resonator device comprising: the external coupling means is disposed within a rectangular parallelepiped cavity shield case;
first to third input coupling means each comprising one magnetic coupling loop; and first to third input coupling means disposed within the rectangular parallelepiped cavity shielding case, each comprising one magnetic coupling loop. The direction of the magnetic lines of force generated surrounding the three columnar dielectrics coincides with the direction of the lines of magnetic force generated by each magnetic coupling loop of the input coupling means to be coupled, while The present invention is characterized in that the magnetic coupling loops of the output coupling means to be coupled with the lines of magnetic force generated surrounding the two columnar dielectric bodies are interlinked with each other.

(Function) In such a method, a solid material with a dielectric constant overwhelmingly larger than that of air is generated in the direction of each electric field line of the triple degenerate TM ₁₁₀ mode, which is the lowest order resonance mode of the rectangular parallelepiped cavity resonator. A dielectric exists. This reduces the external dimensions. Then, a necessary mode and an external circuit are coupled by an external coupling means with a simple structure.

(Example) FIG. 1 is a perspective view showing the main parts of the present invention. In the figure, 1 is a rectangular parallelepiped cavity shield case, and 2 is a composite dielectric in which three columnar dielectrics (the illustrated example is a columnar dielectric with a square cross section) 2a, 2b, and 2c are integrated in a state in which they are perpendicular to each other. It is. It should be noted that the illustrated composite dielectric is shown in an ideal shape with partial deformation performed due to processing technology omitted.
The case 1 may be a metal case, or a case in which a shield electrode film is provided on the inner or outer surface of a rectangular parallelepiped cavity made of the same (ZrSn)TiO ₄ ceramic as the composite dielectric 2, for example. In any case, both axial ends of the composite dielectric must maintain good contact with the case 1 or the shield electrode film.
As the composite dielectric 2, (ZrSn)TiO ₄ ceramic was used. The dielectric constant (ε) is 37.5, and the material temperature coefficient (η _F =−α1/2ηε) is 0±0.5 ppm/°C.

This configuration is characteristic of filters using the conventional TM ₁₁₀ mode.

While inheriting the advantages of high no-load Q and small size, the volume of the resonator device can be reduced to 1/3 compared to conventional filters using the TM ₁₁₀ mode.

By the way, as shown in Figures 2 to 4,
Differences from the present invention will be discussed by considering a case in which a rectangular cavity is provided with a composite dielectric 3 in which two columnar dielectrics 3a and 3b are integrated in a cross shape in a state in which they are orthogonal to each other.

With the configuration shown in Figures 2 to 4, the second
Electric lines of force run in the X-axis direction as shown in the figure.
A dielectric material 3 is used for the TM ₁₁₀ mode and the TM ₁₁₀ mode in which electric lines of force run in the Y-axis direction as shown in Figure 3.
a and 3b come into play effectively. However, at the same time, the higher-order mode as shown in FIG. 4 also exists at almost the same frequency as the above-mentioned fundamental mode, which has the disadvantage of making it difficult to put it into practical use.

If such a configuration is referred to as a dual mode resonator, a configuration such as that of the present invention is referred to as a triple mode resonator.

In this triple mode resonator, the electric lines of force in the higher mode run not only in the X-axis and Y-axis directions but also in the Z-axis direction, so the frequency is considerably lower than that of the fundamental mode and can be ignored in practical use. A triple mode resonator is advantageous in this respect.

Now, when a product is manufactured by implementing the present invention, the electromagnetic fields of the three TM ₁₁₀ modes may interfere with each other due to processing technology. In this case, take measures as shown in FIG.

That is, in FIG. 5, the columnar dielectric 2
In order to prevent the electromagnetic fields of the TM ₁₁₀ modes involving a and 2b from interfering with each other, a coupling adjustment consisting of a pair of screw-shaped metal bodies is provided in a plane that includes both columnar dielectric bodies 2a and 2b. member 4a,
5a may be made to protrude into the case from the ridges 6a, 7a of the case 1.

The columnar dielectrics 2a and 2b are involved, respectively.
When discussing the combination of TM ₁₁₀ modes, the 6th
Let us consider odd mode and even mode as shown in FIG. What is shown is the distribution of electric lines of force.

The average value of the electromagnetic energy currently stored in the resonant system is W~ _t , the magnetic energy contained in the minute part into which the metal is inserted is △W~ _n , and the electric energy contained in the minute part into which the metal is inserted is △. When W~ _e , Δω/Δω ₀ =(ΔW~ _n −ΔW~ _e )/W~ _t .

As you can see from this perturbation equation, inserting a metal in an area with a strong magnetic field will increase the frequency, and inserting a metal in an area with a strong electric field will decrease the frequency.

Therefore, regarding the odd mode shown in FIG. 6, the magnetic energy is stronger than the electric energy near the coupling adjustment member 4a, and conversely, the electric energy is stronger than the magnetic energy near the coupling adjustment member 5a. Therefore, when the degree of insertion of the coupling adjustment member 4a is increased, the resonance frequency of the odd mode increases, and when the degree of insertion of the coupling adjustment member 5a is increased, the resonance frequency of the odd mode is decreased.

Furthermore, in the even mode shown in FIG. 7, the connection adjustment member 4 is opposite to the odd mode.
The electric energy is stronger than the magnetic energy near a, and the magnetic energy is stronger than the electric energy near the coupling adjustment member 5a. Therefore, when the degree of insertion of the coupling adjustment member 4a is increased, the resonance frequency of the even mode decreases, and when the degree of insertion of the connection adjustment member 5a is increased, the resonance frequency of the even mode is increased.

From the above, if the resonance frequency of the odd mode and the resonance frequency of the even mode are made equal by moving the coupling adjustment members 4a and 5a in and out,
The coupling is effectively zero.

In addition, in order to prevent the electromagnetic fields of the TM ₁₁₀ mode involving the columnar dielectrics 2b and 2c from interfering with each other, the coupling adjustment members 4a and 5a are arranged in a plane including the columnar dielectrics 2b and 2c. Connecting adjustment members 4b and 5b similar to
It is preferable to make it protrude into the case from b and 7b.

Furthermore, in order to prevent the electromagnetic fields of the TM ₁₁₀ mode involving the columnar dielectrics 2c and 2a from interfering with each other, these columnar dielectrics 2c and 2a are
The coupling adjustment members 4a, 5 are both included in the plane.
Connection adjustment members 4c, 5c similar to a, 4b, 5b
It is preferable to make them protrude into the case from the ridges 6c and 7c of the case 1.

The point is to consider the aforementioned odd mode and even mode and place the coupling adjustment member at a position that affects them. Therefore, they do not necessarily have to be a pair. The coupling adjustment member may be a dielectric material coated with a metal film.

If the three modes are prevented from interfering with each other in this way, three electrically orthogonal resonators are accommodated in one case.

Conversely, if the resonance frequency of the odd mode and the resonance frequency of the even mode are made different by the degree of insertion of each coupling adjustment member, coupling according to this difference value will be obtained between the two modes. Therefore, by combining the three modes, a three-stage filter will be obtained, as will be described later.

Now, such a resonator is put into practical use by being provided with means for coupling with an external circuit.

FIGS. 8A and 8B show a magnetic coupling loop 8c included in the input coupling means that couples only to the columnar dielectric 2c.
and a magnetic coupling loop 9c possessed by the output coupling means.
This is a representative example.

Now, in the axial direction of the columnar dielectric 2a, the columnar dielectric 2
The axis direction of b and the axis direction of the columnar dielectric body 2c are made to coincide with the X-axis, Y-axis, and Z-axis of the orthogonal coordinate system, respectively.

The magnetic coupling loops 8c and 9c are arranged near one end of the columnar dielectric 2b, with the columnar dielectric 2b in between, and spaced from the surface of the columnar dielectric 2b in the X-axis direction. At this time, magnetic coupling loop 8
The plane including the magnetic coupling loop 9c and the plane including the magnetic coupling loop 9c are made to be orthogonal to the X axis.

One end of each of the magnetic coupling loops 8c, 9c is connected, for example, to the center conductor of a coaxial connector 10c, 11c, and the other end of each is grounded.

An input signal applied to the input coaxial connector 10c causes a current to flow through the magnetic coupling loop 8c, and the direction of the generated magnetic line of force, the direction of the magnetic line of force MF ₁ in the resonance mode involving the columnar dielectric 2a, and the direction of the columnar dielectric 2b are determined. When observing the direction of the magnetic field line MF ₂ of the resonance mode involved and the direction of the magnetic field line MF ₃ of the resonance mode involving the columnar dielectric 2c, it is found that the magnetic field line MF ₃ has the same direction component and is coupled.
Only.

Therefore, if a frequency component of a resonance mode involving the columnar dielectric 2c is present in the signal applied to the input coaxial connector 10c, a resonance phenomenon occurs.

Since the magnetic force line MF ₃ in the resonance mode in which the columnar dielectric body 2c is involved interlinks with the magnetic coupling loop 9c, an output is generated from the coaxial connector 11c.

However, the magnetic coupling loop 9c
The magnetic field line MF ₁ of the resonance mode involving a and the magnetic field line MF ₂ of the resonance mode involving the columnar dielectric 2b
These electromagnetic energies are not extracted from the coaxial connector 11c.

As shown in FIG. 8C, similar coupling means are provided for the dielectric column 2b. The magnetic coupling loop included in the input coupling means relating to the columnar dielectric body 2b is indicated by 8b, and the magnetic coupling loop included in the output coupling means is indicated by 9b.

The magnetic coupling loops 8b and 9b are connected to the columnar dielectric 2a.
They are placed near one end of the columnar dielectric 2a with a distance from the surface of the columnar dielectric 2a in the Z-axis direction. At this time, magnetic coupling loops 8b, 9b
The plane in which it is included is perpendicular to the Z axis.
One end of each of the magnetic coupling loops 8b, 9b is connected, for example, to the center conductor of the coaxial connectors 10b, 11b,
Each other end is grounded.

An input signal applied to the input coaxial connector 10b causes a current to flow through the loop 8b, and the direction of the generated magnetic lines of force, the direction of the magnetic lines of force MF ₁ in the resonance mode involving the columnar dielectric 2a, and the resonance involving the columnar dielectric 2b. The direction of the magnetic field line MF ₂ of the mode and the magnetic field line MF ₃ of the resonance mode involving the columnar dielectric 2c
When observing the directions of , only the magnetic field line MF ₂ has components in the same direction and is coupled.

Therefore, if a frequency component of a resonance mode involving the columnar dielectric 2b is present in the signal applied to the input coaxial connector 10b, a resonance phenomenon occurs.

Then, the line of magnetic force MF ₂ in the resonance mode involving the columnar dielectric 2b interlinks with the loop 9b, so that an output is generated from the coaxial connector 11b.

However, the magnetic coupling loop 9b
The magnetic field line MF ₁ of the resonance mode involving a and the magnetic field line MF ₃ of the resonance mode involving the columnar dielectric 2c
These electromagnetic energies are not extracted from the coaxial connector 11b.

Furthermore, similar means are provided for the columnar dielectric 2a. The magnetic coupling loop possessed by the input coupling means relating to the columnar dielectric body 2a is named 8a, and the magnetic coupling loop possessed by the output coupling means is named 9a.

The magnetic coupling loops 8a and 9a are arranged near one end of the columnar dielectric 2c, with the columnar dielectric 2c in between and spaced apart from the surface of the columnar dielectric 2c in the Y-axis direction. At this time, the plane including the loops 8a and 9a is made perpendicular to the Y axis.

One end of each of the magnetic coupling loops 8a, 9a is connected, for example, to the center conductor of a coaxial connector 10a, 11a, and the other end is grounded.

An input signal applied to the input coaxial connector 10a causes a current to flow through the loop 8a, and the direction of the generated magnetic lines of force, the direction of the magnetic lines of force MF ₁ in the resonance mode involving the columnar dielectric 2a, and the resonance involving the columnar dielectric 2b. The direction of the magnetic field line MF ₂ of the mode and the magnetic field line MF ₃ of the resonance mode involving the columnar dielectric 2c
When observing the directions of , only the magnetic field line MF ₁ has a component in the same direction and is coupled.

Therefore, if a frequency component of a resonance mode involving the columnar dielectric 2a is present in the signal applied to the input coaxial connector 10a, a resonance phenomenon occurs.
Since the line of magnetic force MF ₁ in the resonance mode involving the columnar dielectric 2a interlinks with the loop 9a, an output is generated from the coaxial connector 11a.

However, since the loop 9a does not interlink with the magnetic field line MF _{2 in the resonance mode involving the columnar dielectric 2b} or the magnetic force line MF ₃ in the resonance mode involving the columnar dielectric 2c, these electromagnetic energies are transferred to the coaxial connector 11a.
It cannot be removed from the

These magnetic coupling loops 8a to 8c, 9a
The shapes of 9c to 9c are not limited to those shown in the drawings, and may be ring-shaped, for example.

With the above configuration, the dielectric resonator device according to the embodiment of the present invention can be expressed as an equivalent circuit as shown in FIG.

In FIG. 9, _R1 is a resonator related to a resonance mode involving the columnar dielectric 2a, _R2 is a resonator related to a resonance mode involving the columnar dielectric 2b, and _R3 is a resonance related to the columnar dielectric 2c. Resonators related to the mode, 1 and 1' are the input and output ends of a filter made up of resonator _R1, respectively; 2 and 2' are the input and output ends of a filter made up of resonator _R2 , respectively; 3,
3' are the input end and output end of a filter composed of a resonator _R3 , respectively. K ₁₂ is the degree of coupling between resonators R ₁ and R ₂ , K ₂₃ is the degree of coupling between resonators R ₂ and R ₃ , and K ₃₁ is the degree of coupling between resonators R ₃ and R ₁ .

Therefore, if the degrees of coupling K ₁₂ , K ₂₃ , and K ₃₁ are all made substantially zero by adjusting the coupling adjustment member shown in FIG. , three resonators in a non-interfering state are constructed.

That is, for example, a signal input to input terminal 1 is filtered and output only from output terminal 1'. A signal input to the input end 2 is filtered and output only from the output end 2'. A signal input to the input end 3 is filtered and output only from the output end 3'.

Figure 10 shows the filter characteristics, and in the figure
S ₁₁ ′ is the response between input end 1 and output end 1′,
S ₂₂ ′ is the response between input end 2 and output end 2′,
S ₃₃ ′ indicates the response between the input end 3 and the output end 3′.

Note that when configuring a filter using three resonators, for example, resonator R ₁ , resonator R ₂ , and resonator R ₃ are coupled in this order, and resonator R ₁ has a loop 8a. Input coupling means such as input coupling means are combined, and resonator R ₃ is combined with output coupling means such as output coupling means having a loop 9c.

Then, an equivalent circuit as shown in FIG. 11 is obtained. Then, by adjusting the coupling adjustment member provided for each resonator as shown in FIG. 5, the coupling degrees K ₁₂ and K ₂₃ are set to appropriate values, respectively, and K ₃₁
When substantially zero, the signal input to the input coupling means is sequentially filtered by resonators R ₁ , R ₂ , R ₃ and output from the output coupling means. A non-polar filter is constructed in one case. will be done. If K ₃₁ is also set to an appropriate value, a polar filter will be constructed.

(Effects) As is clear from the above embodiments, this invention effectively utilizes the three mutually orthogonal TM ₁₁₀ modes existing in the rectangular parallelepiped cavity shield case, so the size is 1/3 that of the conventional one. This is an epoch-making device that can be made smaller and reduce costs. Further, the connection with an external circuit is made by an external coupling means having a simple structure.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the main part of an embodiment of the present invention, FIGS. 2, 3, and 4 are explanatory diagrams explaining dual mode resonance, and FIG. 5 is a main part of an embodiment of the invention. FIGS. 6 and 7 are explanatory diagrams for explaining the embodiment of this invention. FIGS. 8A, B, and C are internal explanatory diagrams of the embodiment of this invention. FIG. FIG. 10 is a filter characteristic diagram of the embodiment of the present invention, and FIG. 11 is an equivalent circuit when a three-stage filter is configured. 1... Shield case, 2... Composite dielectric, 8a,
8b, 8c, 9a, 9b, 9c...magnetic coupling loop.

Claims (1)

[Claims] 1. Three columnar dielectrics are integrated in a rectangular parallelepiped cavity shielding case in a state perpendicular to each other, and the axial direction of one of the three columnar dielectrics is the Z axis. In a rectangular coordinate system that matches
TM ₁₁₀ mode resonance, TM ₀₁₁ mode resonance and
In a dielectric resonator device comprising a dielectric resonator that utilizes TM ₁₀₁ mode resonance and an external coupling means for coupling the dielectric resonator to an external circuit, the external coupling means is a rectangular parallelepiped cavity shield. first to third input coupling means disposed within the case, each comprising one magnetic coupling loop; and first to third input coupling means disposed within the rectangular parallelepiped cavity shielding case, each comprising one magnetic coupling loop. The direction of the magnetic lines of force generated surrounding the three columnar dielectrics and the direction of the lines of magnetic force generated by each magnetic coupling loop of the input coupling means to be coupled are respectively A dielectric resonator device characterized in that the magnetic coupling loops of the output coupling means to be coupled with lines of magnetic force generated surrounding the three columnar dielectric bodies are interlinked with each other.