JP3484769B2 - TM multimode dielectric filter - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a TM multi-mode dielectric filter using a TM multi-mode resonator. 2. Description of the Related Art Among conventional TM multi-mode dielectric filters, a TM dual-mode dielectric filter will be described with reference to FIG. The TM mode resonance elements 11 and 12
The TM dual mode resonator R1 is formed by being integrally formed in a cross shape orthogonal to each other. Also, the TM mode resonance element 1
Similarly, the TM double mode resonator R2 is formed by integrally molding the components 3 and 14. These TM dual mode resonators R
1, R2 is connected and housed in the conductive cavity 15,
TM dual mode resonators R10 and R20 are formed. Then, these TM dual mode resonators R10, R20
Are integrally joined with a partition plate 16 interposed therebetween, and TM2
A heavy mode dielectric filter is configured. In addition, the partition plate 1
6 has a coupling window 16a formed of a plurality of slits. However, the conventional TM dual-mode dielectric filter has a large number of coupling windows 6a formed in the partition plate 16 and an unnecessary magnetic field of 2 to 10%.
It was difficult to realize the filter characteristics as designed, especially the attenuation pole characteristics, in combination. Accordingly, the present invention provides a coupling window at one end or both ends of a partition plate to reduce unnecessary magnetic field coupling, prevent a decrease in Q, and provide a TM which is easy to design and easy to manufacture. It is an object to provide a multi-mode dielectric filter. [0005] The means for solving the problems of the present invention are as follows. A TM multi-mode resonator is formed by intersecting at least two TM mode resonance elements with each other. A plurality of TM multi-mode resonators are connected and housed in a conductive cavity via a partition plate. In a TM multi-mode dielectric filter composed of a multi-mode resonator, a coupling window for magnetically coupling a former-stage TM multi-mode resonator and a latter-stage TM multi-mode resonator is formed at one end or both ends of the partition plate. 1. A TM multi-mode dielectric filter, comprising: According to the present invention, at one end or both ends of a partition plate,
Since a coupling window for magnetically coupling the first and second TM multimode resonators is provided, the ratio of unnecessary magnetic field coupling is reduced, and Q
Is suppressed, and the design of the attenuation pole characteristic is facilitated. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of the present embodiment. In the figure, reference numerals 1 and 2 denote TM mode resonance elements, each of which is made of a dielectric ceramic material by pressing or the like.
The TM dual-mode resonator R1 is integrally formed in a cross shape so as to be orthogonal to each other. This TM dual mode resonator R
Coupling grooves 5 are formed from two diagonal corners of the one cross-shaped crossing portion in diagonal directions. Because of the coupling groove 5, the TM mode resonance elements 1, 2 are connected via the electric power lines of the even mode and the electric power lines of the odd mode.
Are combined. The four cross-shaped tips of the TM dual mode resonator R1 are connected to the four inner surfaces of the conductive cavity 6, respectively, to form a TM dual mode resonator R10. Note that the TM dual mode resonator R1 and the conductive cavity 6 constituted by the TM mode resonant elements 1 and 2 are usually integrally formed of a dielectric material, and by providing a conductor on the outer surface of the conductive cavity 6, TM
The dual mode resonator R10 is configured. On the other hand, similarly to the TM mode resonance elements 1 and 2, the TM mode resonance elements 3 and 4
M dual mode resonator R2 and TM dual mode resonator R
20. These TM dual mode resonators R10, R10
Reference numeral 20 is connected via the partition plate 7. This partition plate 7
Is metal or metallized dielectric ceramic. Then, at the upper end of the partition plate 7,
A rectangular window 7 a is provided in a direction perpendicular to the TM mode resonance element 2 and in a direction parallel to the TM mode resonance element 1. An electric field is generated in the dielectrics of these TM mode resonant elements 1 and 2, and a magnetic field is generated around the dielectric in a direction perpendicular to the electric field. The direction of the window 7a is horizontal to the magnetic field surface of the TM mode resonant element 2. , So that the magnetic field component is transmitted. In FIG. 1, the number of the windows 7a is one, but similar ones may be formed at the lower end of the partition plate 7, as shown in FIG. 8a and 8b are input / output loops. The present embodiment has the above-described configuration, and the operation will be described below. The electromagnetic wave introduced from the input loop 8a is magnetically coupled with the TM mode
An electric field is generated in the M mode resonance element 1 and the TM mode resonance element 2. Since the magnetic field component of the TM mode resonance element 2 generated in response to the electric field is on the same horizontal plane (in the drawing) as the direction of the window 7a, the next stage TM2
Magnetic field coupling is performed with the TM mode resonance element 3 of the heavy mode resonator R20. Due to this coupling magnetic field, an electric field is generated in the dielectrics of the TM mode resonance elements 3 and 4, and the magnetic field of the TM mode resonance element 4 generated in response to the electric field is linked to the output loop 8b and the output is output. It is taken out from the loop 8b. Since the magnetic field surface generated by the TM mode resonance element 1 intersects the direction of the window 7a at right angles, the magnetic field can hardly penetrate into the window 7a and is cut off. Become. Moreover, since the window 7a is provided at the center of the upper end of the partition plate 7, the TM mode resonance element 2
In this embodiment, the unnecessary magnetic field coupling between the TM mode resonant element 1 and the next-stage TM mode resonant element 4 is 0.2 ~ 0.5%, which is extremely small. According to the present invention, since the coupling window for magnetic field coupling is formed at one end or both ends of the partition plate, the ratio of unnecessary magnetic field coupling is reduced, and the multi-slit partition plate is formed. Compared with the conventional example used, the current distribution is not disturbed and the decrease in Q is suppressed, and the design of the filter characteristic having the attenuation pole becomes very simple. Further, since the slit pattern of the coupling window has a simple shape, the production becomes easy.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a TM dual mode dielectric filter according to one embodiment of the present invention. FIG. 2 is a perspective view of a partition plate according to another embodiment. FIG. [Description of References] 1, 2, 3, 4 TM mode resonance elements R1, R2 TM double mode resonator R10, R20 TM double mode resonator 5 Coupling groove 6 Conductive cavity 7 Partition plate 7a Windows 8a, 8b Input / output loop

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01P 1/20 H01P 1/208 H01P 7/10

Claims (1)

(57) Claims 1. A TM multi-mode resonator is formed by intersecting at least two TM mode resonance elements with each other, and a plurality of the TM multi-mode resonators are formed in a conductive cavity. In a TM multi-mode dielectric filter composed of a plurality of TM multi-mode resonators connected and housed via a partition plate, a first-stage TM multi-mode resonator and a second-stage TM are provided at one end or both ends of the partition plate. A TM multi-mode dielectric filter, wherein a coupling window for magnetically coupling with a multi-mode resonator is formed.