JPH07202531A - Dielectric resonator and filter device - Google Patents

Abstract

PURPOSE:To miniaturize the filter device having a multistage constitution by providing one of TM mode dielectric resonators constituting a double mode dielectric resonator with a hole for resonance frequency adjustment. CONSTITUTION:The end part of one TM mode dielectric resonator 3b among two orthogonal TM mode dielectric resonators 3a ana 3b is pierced by a hole 5 for resonance frequency adjustment. Though both TM mode dielectric resonators 3a and 3b have the same resonance frequency without the hole 5, the resonator 3b has the effective dielectric constant reduced to have a higher resonance frequency when the hole 5 is provided in the TM mode dielectric resonator 3b or its diameter is increased. Consequently, this fact is utilized to correct the deviation of the resonance frequency due to coupling between TM mode dielectric resonators 3a and 3b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric resonator and a filter device. Specifically, it relates to a TM dual mode dielectric resonator that can be used in a coupling stage with a Qe loop such as a filter. Further, the present invention relates to a multistage filter device using the dielectric resonator.

[0002]

2. Description of the Related Art FIG. 5 shows two single mode dielectric resonators 52 and 53 and one dual mode dielectric resonator 5.
4 is a partially cutaway perspective view showing the structure of a four-stage filter device 51 in which 4 is housed in a metal case 55. FIG. The single-mode dielectric resonators 52 and 53 have a TM-mode dielectric resonator 57 housed in a conductive case 56 that functions as a waveguide. In addition, the dual mode dielectric resonator 54
Is a TM double mode dielectric resonator 60 in which two TM mode dielectric resonators 58 and 59 are integrated in a cross shape so as to be orthogonal to each other, and is housed in a conductive case 61. It is disclosed in Japanese Patent Laid-Open No. 61-121502.

In this filter device 51, however, the Qe loop 63 provided on the inner surface side of the connector 62 on both end surfaces and the TM mode dielectric resonator 57 of the first-stage single mode dielectric resonator 52 are magnetically coupled. Then, the TM mode dielectric resonator 57 and the TM dual mode dielectric resonator 60 are electromagnetically coupled to each other, and the TM dual mode dielectric resonator 6 is further coupled.
0 and the TM mode dielectric resonator 57 of the final-stage single mode dielectric resonator 53 are electromagnetically coupled, and the TM mode dielectric resonator 57 and the Qe loop 63 provided on the other connector 62 are magnetically coupled. And constitutes a four-stage filter.

[0004]

When a dual mode dielectric resonator is used, two TM mode dielectric resonators are integrated in a cross shape, so two two single mode dielectric resonators are used. The filter device can be downsized as compared with the case where they are arranged side by side. Therefore, even in the above-described four-stage filter device, if two dual-mode dielectric resonators can be used, it is expected that the filter device will be further downsized.

However, in the conventional dual-mode dielectric resonator, the two TM-mode dielectric resonators have the same resonance frequency in a single state not incorporated in the filter device or the like. For this reason, when this double mode dielectric resonator is incorporated in the filter device as described above, if it is arranged in the coupling stage with the Qe loop, it is affected by the Qe loop, and therefore the TM mode magnetically coupled with the Qe loop is obtained. There is a problem in that the dielectric resonator and the TM mode dielectric resonator that is not coupled to the Qe loop cause a shift in resonance frequency. That is, when the resonance frequencies of both TM mode dielectric resonators are different, it becomes impossible to determine the coupling coefficient between both modes from the resonance frequencies feven and fodd of the so-called even mode and odd mode.

Therefore, in the prior art, a single mode dielectric resonator is used in the coupling stage with the Qe loop as in the filter device shown in FIG. 5, which is an obstacle to making the filter device compact. It was

The present invention has been made in view of the above-mentioned drawbacks of the conventional examples, and an object thereof is to determine the resonance frequencies of both TM mode dielectric resonators of a dual mode dielectric resonator. Each TM mode dielectric resonator is individually adjustable, and is adjusted so that the resonance frequencies of both TM mode dielectric resonators are equal in a state where one TM mode dielectric resonator is coupled to the Qe loop.

[0008]

SUMMARY OF THE INVENTION In a dielectric resonator according to the present invention, a dual mode dielectric resonator in which two TM mode dielectric resonators are made orthogonal to each other and integrally formed is housed in a conductive case. In the dielectric resonator formed as described above, one of the two TM mode dielectric resonators constituting the dual mode dielectric resonator is provided with a hole for resonance frequency adjustment in the TM mode dielectric resonator. It has a feature.

Also, in the filter device of the present invention, the dielectric resonator is arranged in a coupling stage with the Qe loop, and the TM mode coupled with the Qe loop is adjusted by adjusting the size of the hole for adjusting the resonance frequency. It is characterized in that the resonance frequencies of the TM-mode dielectric resonator not coupled to the dielectric resonator and the Qe loop are made equal.

[0010]

In the dielectric resonator of the present invention, one TM
Since the mode dielectric resonator has a hole for adjusting the resonance frequency, the TM mode dielectric resonator coupled to the Qe loop and the TM mode dielectric not coupled to the Qe loop are adjusted by adjusting the size of the hole. The deviation of the resonance frequency of the body resonator can be adjusted. Further, the shift of the resonance frequency of one TM mode dielectric resonator caused by the coupling between the orthogonal TM mode dielectric resonators can be similarly corrected.

In this way, the resonance frequency of one TM mode dielectric resonator coupled to the Qe loop and the resonance frequency of the other TM mode dielectric resonator not coupled to the Qe loop can be made equal. Therefore, the TM dual mode dielectric resonator can be used in the coupling stage with the Qe loop of the filter device, and the filter device having a multi-stage configuration can be further downsized.

[0012]

1 (a) and 1 (b) are a perspective view and a side sectional view showing a dual mode dielectric resonator A according to an embodiment of the present invention. This dual-mode dielectric resonator A has a TM dual-mode dielectric resonator 2 integrated in a conductive case 1 that functions as a waveguide. The conductive case 1 is a metal case, or a ceramic case body formed at the same time as the TM mode dielectric resonator 2 is baked with silver paste or the like to form a ground electrode. The TM dual mode dielectric resonator 2 is made of a dielectric ceramic, and has two TM ₁₁₀ modes, for example.
The mode dielectric resonators 3a and 3b are orthogonal to each other and integrally formed into a cross shape. Case 1
Is made of metal, each TM mode dielectric resonator 3a,
The TM double-mode dielectric resonator 2 is electrically and mechanically coupled to the inner surface of the case 1 by a conductor layer (not shown) made of a thick silver film formed on both end surfaces of 3b.

The lines of electric force indicated by solid arrows in the TM double-mode dielectric resonator 2 of FIG. 1 are the odd-mode lines of electric force Eo generated in the TM double-mode dielectric resonator 2 and are indicated by broken lines. The lines of electric force indicated by the arrows are lines of electric force Ee in the even mode. At the pair of inner corners through which only the odd-mode electric lines of force Eo pass, the intersecting portions of the TM double-mode dielectric resonator 2 are cut out in a groove shape. Resonance vibration and odd
Coupling is caused between the resonance vibrations of the modes, and the mutual coupling coefficient can be adjusted by adjusting the size of the groove-shaped notch 4. 2 orthogonal
T of one of the two TM mode dielectric resonators 3a and 3b
A resonance frequency adjusting hole 5 is penetrated through the end of the M-mode dielectric resonator 3b. When the resonance frequency adjusting hole 5 is not opened, both TM mode dielectric resonators 3 are formed.
Although the resonance frequencies of a and 3b are equal, when the resonance frequency adjusting hole 5 is opened in the TM mode dielectric resonator 3b or the opening diameter of the resonance frequency adjusting hole 5 is increased, the TM
Since the effective dielectric constant of the mode dielectric resonator 3b decreases, the resonance frequency increases, and the difference between the opening diameter of the resonance frequency adjusting hole 5 and the resonance frequency of both TM mode dielectric resonators is as shown in FIG. It is shown in a relationship.

As described above, in the case of the dual mode dielectric resonator A alone, when the resonance frequency adjusting hole 5 is provided, the resonance frequency shift occurs between the TM mode dielectric resonators 3a and 3b. By using, it is possible to correct the deviation of the resonance frequency generated between the TM mode dielectric resonators 3a and 3b caused by the coupling between the orthogonal TM mode dielectric resonators 3a and 3b. Also, when one TM mode dielectric resonator, for example, 3a is magnetically coupled to the Qe loop, the TM mode dielectric resonator 3 is magnetically coupled.
The resonance frequency shifts in a and the resonance frequency increases, but the other TM mode dielectric resonator, for example, 3
By providing the resonance frequency adjusting hole 5 in b, the resonance frequency of the TM mode dielectric resonator 3b can be increased, and by adjusting the opening diameter of the resonance frequency adjusting hole 5, the TM mode dielectric resonance coupled with the Qe loop is obtained. The resonance frequencies of the child 3a and the TM mode dielectric resonator 3b that is not coupled to the Qe loop can be made equal.

By changing the depth or size of the groove-shaped notch 4, the coupling coefficient of both TM mode dielectric resonators 3a and 3b can be changed. At this time, both TM mode dielectric resonators 3a. , 3b are adjusted to have the same resonance frequency, the even mode resonance frequency fev
The coupling coefficient can be determined from en and the resonance frequency fodd of the odd mode.

FIG. 3 is a partially broken perspective view showing a filter device B having a four-stage structure according to the present invention, and FIG. 4 is a perspective view showing the structure of the main part thereof. In the metal case 11, the dual mode dielectric resonators A1 and A2 having the structure as shown in FIGS.
2 of the dual mode dielectric resonators A1 and A2 are arranged side by side, and the Q mode provided on the inner surface side of the connector 12 at both ends and the TM mode dielectric resonator 3a oriented horizontally.
The e-loop 13 is magnetically coupled. Further, a partition plate 15 provided with an electrode pattern having stripe-shaped slits 14 is provided between the dual mode dielectric resonators A1 and A2. TM mode dielectric resonators 3b and 3b oriented in the vertical direction of A1 and A2 are electrically coupled to each other.

When the dual mode dielectric resonators A1 and A2 are arranged in the coupling stage with the Qe loop 13 as described above,
The resonance frequency of the TM mode dielectric resonator 3a coupled to the Qe loop 13 is affected, but in this filter device B, the resonance frequency adjusting hole 5 is adjusted to adjust the resonance frequency to be coupled to the Qe loop 13. The resonance frequencies of the TM mode dielectric resonator 3b that is not connected and the TM mode dielectric resonator 3a that is coupled to the Qe loop 13 are adjusted to be equal. Therefore, it is possible to adjust the coupling coefficient to a desired value from the even mode resonance frequency feven and the odd mode resonance frequency fodd. Therefore, the dual-mode dielectric resonator can be used also in the coupling stage with the Qe loop, and the filter device can be reduced in size and weight.

[0018]

According to the present invention, the TM-mode dielectric resonator is provided with a hole for adjusting the resonance frequency.
The resonance frequency of the mode dielectric resonator can be corrected. Therefore, the resonance frequencies of the TM mode dielectric resonator coupled to the Qe loop and the TM mode dielectric resonator not coupled to the Qe loop can be equalized, and the TM dual mode dielectric resonator can be used as a filter device. It can be used in a coupling stage with a Qe loop. Therefore, it is possible to further reduce the size of the multi-stage filter device.

The resonance frequency adjusting holes are used to form both TMs produced by coupling between orthogonal TM mode dielectric resonators.
The shift of the resonance frequency between the mode dielectric resonators can be similarly corrected.

[Brief description of drawings]

1A and 1B are a perspective view and a side sectional view showing a dielectric resonator according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between an opening diameter of a hole provided in a TM mode dielectric resonator and a difference in resonance frequency between both TM mode dielectric resonators.

FIG. 3 is a partially cutaway perspective view showing a four-stage filter device according to the present invention.

FIG. 4 is a diagram showing a configuration of a main part of the above filter device.

FIG. 5 is a partially cutaway perspective view showing a conventional four-stage filter device.

[Explanation of symbols]

 A, A1, A2 Double mode dielectric resonator B Filter device 1 Case 2 TM Double mode dielectric resonator 3a, 3b TM mode dielectric resonator 4 Groove notch 5 Resonance frequency adjusting hole 13 Qe loop

Claims (2)

[Claims] 1. A dielectric resonator comprising a two-mode dielectric resonator in which two TM-mode dielectric resonators are formed orthogonally to each other and integrally formed, and is housed in a conductive case. A dielectric resonator, wherein one of the two TM mode dielectric resonators forming the dielectric resonator is provided with a hole for adjusting a resonance frequency in a TM mode dielectric resonator. 2. A dielectric resonator according to claim 1, which is arranged in a coupling stage with a Qe loop, and which is coupled with the Qe loop by adjusting the size of the hole for adjusting the resonance frequency.
TM not coupled with mode dielectric resonator and Qe loop
A filter device characterized in that each resonance frequency of a mode dielectric resonator is made equal.