JPH02241101A - Structure for dielectric filter - Google Patents

Abstract

PURPOSE:To obtain a dielectric filter with low cost and suitable for mass- production without cutting by cutting off a metallic pipe to a length determining a prescribed filter characteristic, and bonding a supporting plate which is made to a material with less loss and on which dielectric resonators are arranged to the inside of the cut-off metallic pipe. CONSTITUTION:A long metallic rod 1 as a raw material is extruded or dawn into a metallic pipe 2 as a rectangle having a cross section showing a cut-off characteristic at the operating frequency. The metallic pipe 2 is cut off into a length determining a prescribed filter characteristic to from a metallic pipe piece 3. Dielectric resonators 41, 42, 43 are arranged on a supporting plate 5 made of a material with less loss and fitted in the inside of the metallic pipe piece 3 and the supporting plate 5 is bonded to the inside of the metallic piece 3. In this case, since no complicated cutting for the manufacture of the dielectric filter is not required, man-hour of the manufacture of the dielectric filter is reduced, the cost is reduced and the effect of mass-production is obtained.

Description

[Detailed Description of the Invention] [Summary] A dielectric resonator for magnetic field coupling is placed inside a waveguide that has a cutoff at the operating frequency. The aim is to provide a dielectric filter structure that is suitable for mass production at low cost and does not involve cutting the cut-off waveguide in which it is placed.The aim is to create a dielectric filter structure that is suitable for mass production at low cost without having to cut the cut-off waveguide. A metal pipe is formed by extruding or pulling out a rectangular hole, the metal pipe is cut to a length that determines the required filter characteristics, and dielectric resonators are arranged and installed inside the cut metal pipe piece, resulting in a material with low loss. A pair of grooves are formed on the inner surface of the metal vibrator at the same time as the rectangular hole is extruded or pulled out from the metal rod, and a support plate of the metal pipe cut to a required length is bonded to the support plate. A support plate made of a material with low loss, on which dielectric resonators are attached side by side, is inserted into the pair of grooves and bonded to the support plate.

[Industrial application field]

The present invention relates to a bandpass filter used in microwave/millimeter wave communication equipment, and particularly to a bandpass filter in which a magnetically coupled dielectric resonator is placed inside a waveguide whose transmission characteristics are cut off. This invention relates to the structure of a dielectric filter.

[Conventional technology]

The structure of the above dielectric filter is as shown in FIG.
1A, 5□ pieces, and 53A pieces can be placed inside it, and an aluminum block into which a rectangular waveguide 2A can be cut out with dimensions such that the transmission characteristics are cut off at the frequency used is placed into the upper block 61A and the lower block 6□ pieces. It was divided into blocks, and rectangular or round holes of the required dimensions were cut into each block.

[Problem to be solved by the invention]

In the above conventional structure, even if the cost of the dielectric resonators 1, a, 1□g, 1+a placed inside the structure is reduced, when viewed as an entire dielectric filter including the cutoff waveguide 2A, There was a problem of high cost. An object of the present invention is to provide a structure of a dielectric filter that is suitable for mass production at low cost and does not involve cutting a cutoff waveguide in which a dielectric resonator is disposed.

[Means to solve the problem]

As shown in Fig. 1, the problem was to form a metal pipe 2 by extruding or pulling out a rectangular hole with dimensions that cut off the transmission characteristics at the operating frequency from a long metal rod 1 made of aluminum or the like.
is cut into a length that determines the required filter characteristics, and a dielectric resonator 4. is placed inside the cut metal pipe piece 3. ．． 4□
, 43 are arranged and adhered to a support plate 5 made of a material with low loss such as quartz.

In the principle diagram of FIG. 1 showing the structure of the dielectric filter of the present invention, 1 is a long metal rod as a material.

2 is a metal pipe formed by extruding or pulling out the metal rod 1 into a rectangular cross-sectional size that is cut off at the operating frequency.

3 is a metal pipe piece obtained by cutting the metal pipe 2 into a length that determines the required transmission characteristics.

41.4□, 43 are dielectric resonators mounted inside the metal pipe piece 3.

5 is a dielectric resonator 41.4□, 4. It is a support plate made of low-loss material that is mounted side by side on it.

Then, the support plate 5 is bonded to the inside of the metal pipe piece 3.

[Effect]

A metal pipe 2 is made by extruding or pulling out a long metal rod 1 as a raw material into a rectangular cross-sectional size that is cut-off at the operating frequency. The metal pipe 2 is cut into a length that determines the required filter characteristics to obtain a metal pipe piece 3. Inside the metal pipe piece 3, dielectric resonators 41, 42, and 43 are mounted side by side on a support plate 5 made of a material with low loss, and the support plate 5 is adhered to the inside of the metal pipe piece 3. Electrically, the dielectric resonators 40, 4□, and 43 pass only the resonant frequency due to the magnetic coupling between the dielectric resonator 41, the dielectric resonator 4□, and the dielectric resonator 43, as in conventional dielectric filters. Since the required filter characteristics are satisfied, there is no problem. In addition, mechanically, as mentioned above, there is no complicated cutting process,
Metal pipe 2 simply extruded or pulled out from a long metal rod 1
is cut to a required length to obtain a metal pipe piece 3, and inside the metal pipe piece 3, dielectric resonators 41, 4□, and 43 are installed side by side on a support plate 5 with low loss. The simple work of gluing the metal pipe piece 3 to the inside of the metal pipe piece 3 is sufficient.

Therefore, the structure of the dielectric filter of the present invention is suitable for mass production at low cost, and the problem is solved.

〔Example〕

While FIG. 1 shows an embodiment of the present invention as it is, FIG. 2 shows the structure of a dielectric filter according to another embodiment of the present invention.

In the embodiment shown in FIG. 2, a pair of horizontal grooves 2S+ and 2s2 are simultaneously formed on the inner surface of the hole having a rectangular cross section in the metal pipe 2 extruded or drawn from the aluminum rod of the metal rod 1 as the raw material. Loss caused by attaching the dielectric resonators 41, 4□, 43 side by side in the pair of grooves 2s1.23z of the aluminum tube piece 3, which is provided by extrusion or drawing and cutting the aluminum tube 2 to a required length. A support plate 5 made of quartz or the like with a small amount of dirt is inserted and fixed.

Compared to the embodiment shown in FIG. 1, this embodiment is different from the embodiment shown in FIG. Easy and advantageous. In addition, the thickness of the quartz support plate 5 can be reduced, and the adhesive that fixes the support plate 5 does not enter the inside of the aluminum tube piece 3 of the cut-off waveguide, which reduces loss and improves the characteristics of the dielectric filter. can also be expected to improve.

The structures of the dielectric filters of both the embodiments shown in FIG. 1 and FIG. 2 require simple work and are suitable for mass production at low cost, so there is no problem.

〔Effect of the invention〕

As described above, according to the present invention, complicated cutting is not required for manufacturing a dielectric filter, so that it is possible to reduce the number of man-hours for manufacturing a dielectric filter, reduce costs, and improve mass productivity.

[Brief explanation of drawings]

Fig. 1 is a principle diagram showing the structure of a dielectric filter of the present invention, Fig. 2 is an external view showing the structure of a dielectric filter according to an embodiment of the invention, and Fig. 3 is a structural diagram of a conventional dielectric filter. be. In the figure, 1 is a metal rod, 2 is a metal vibrator, 3 is a metal pipe piece, 41
．． 4□, 43 are dielectric resonators, and 5 is a support plate.

Claims (2)

[Claims] 1. In the structure of a dielectric filter in which a magnetic field-coupled dielectric resonator is placed inside a waveguide that has a cutoff at the operating frequency, the transmission characteristics of the long metal rod (1) as the material have a cutoff at the operating frequency. A metal pipe (2) is formed by extruding or pulling out a rectangular hole with the same dimensions, the metal pipe is cut into a length that determines the required filter characteristics, and the dielectric resonator is placed inside the cut metal pipe piece (3). (4_1, 4_2
, 4_3) are attached side by side and a supporting plate (5) made of a material with low loss is adhered. 2. A pair of grooves (2s_1) are formed on the inner surface of the metal pipe (2).
, 2s_2) are formed at the same time as extrusion or drawing out of the rectangular hole from the metal rod (1), and the pair of grooves (
2s_1, 2s_2), the dielectric resonator (4_1,
2. The structure of the dielectric filter according to claim 1, characterized in that a support plate (5) made of a material with low loss is inserted and bonded to the support plate (5) to which 4_2, 4_3) are attached side by side.