JPS6322723Y2 - - Google Patents

Description

[Detailed explanation of the idea] This invention relates to band rejection filters.

Conventionally, a band rejection filter has a conductor block with a housing hole, and a dielectric coaxial TEM is inserted into the housing hole.
It is constructed by inserting a resonator and fixing it electrically and mechanically. For this fixing, conductive adhesive is applied to either the inner surface of the accommodation hole or the outer conductor of the dielectric coaxial TEM resonator, or both, and the resonator is fitted into the accommodation hole. ing.

However, in such conventional band-stop filters, it is difficult to perform the above-mentioned bonding reliably.
In addition, there was a problem that the conductive adhesive adhered to unnecessary places, such as the open end face of the resonator, adversely affecting the characteristics. In addition, in general, in a band-stop filter, each resonator needs to be connected with a transmission line having a length of 1/4 wavelength, but the structure for accommodating this transmission line within the case was an obstacle to miniaturization.

The purpose of this invention is to reliably electrically connect the outer conductor of a dielectric coaxial TEM resonator and the case.

Another purpose of this invention is to reduce the amount of expensive conductive adhesive used.

Another purpose of this invention is to improve work efficiency.

Another object of this invention is to provide a compact band-stop filter.

The gist of this invention is to fit a dielectric coaxial TEM resonator in which a solid dielectric exists between the inner and outer conductors into a housing hole provided in a conductor block, and to attach the inner wall surface of the housing hole to the conductor block. An opening is formed to communicate a portion of the conductor block with one main surface of the conductor block, and the outer conductor of the dielectric coaxial TEM resonator is exposed to the opening, and the edge of the opening and the main surface of the resonator are exposed. The band rejection filter is characterized in that a portion of the outer conductor near the open end is bonded with a conductive adhesive, and a coaxial cable connecting the center conductors of the resonator is housed near the opening.

The development process and embodiments of this invention will be described below with reference to the drawings.

1 to 4 are diagrams for explaining the process of establishing the present invention. In Figure 1, 1 is 1/
This resonator 1 is a 4-wavelength dielectric coaxial TEM resonator, and the resonator 1 is made of a cylindrical (cylindrical, rectangular, etc.) body 2 made of a titanium oxide ceramic dielectric, etc., and a silver paste is baked on the inner and outer surfaces of the body 2. , an inner conductor 3 and an outer conductor 4 are formed by an electroless copper plating method, and an electrode 5 for short-circuiting the inner conductor 3 and outer conductor 4 is formed on the entire right end surface in the figure by the same method. In order to connect the inner conductor 3 to the outside,
If necessary, a metal rod-shaped terminal 6 having a stopper collar is inserted into the central hole from the open end, and at this time, the terminal 6 and the inner conductor 3 are bonded together using a conductive adhesive.

In FIGS. 2 to 4 showing a bandpass filter in which the resonator 1 is housed in a case, 10 is a main case serving as a conductor block, which has a rectangular parallelepiped made of conductor, for example, duralumin, and a housing hole. The resonator 1 shown in FIG. 1 is fitted into each housing hole 11. Reference numeral 12 denotes a capacitor, which has a structure in which capacitor electrodes 14 and 15 are provided on opposing principal planes of a disc-shaped ceramic dielectric 13. Two capacitors 12 are soldered to the terminal 6 of each resonator 1 with their axial directions aligned. The center conductor of the input coaxial connector 16 provided on one side of the main case and the first stage resonator 1
The input capacitor 12 of the first stage resonator 1 is connected to the output capacitor 1 of the first stage resonator 1 by a wire 17.
2 and the input-side capacitor 12 of the second-stage resonator 1 are connected by a wire 18 that is insulated through a hole provided between the housing holes 11 and 11, and the output-side capacitor 12 of the second-stage resonator 1 The capacitor 12 and the input side capacitor 12 of the final stage resonator 1 are connected to the accommodation holes 11, 11.
A wire 19 inserted through the hole provided in between is connected to the output side capacitor 12 of the final stage resonator 1 and the center conductor of the output coaxial connector 20 provided on one side of the main case 10. is wire 2
Connected by 5. In this way, a bandpass filter is constructed.

A square opening 21 is provided on one of the main side surfaces of the main case 10, and the outer conductors 4, 4, 4 of the resonators 1, 1, 1 are exposed from this opening 21. The upper edge of the opening 21 in the figure and the outer conductors 4, 4, 4 are bonded with a conductive adhesive 22, and the lower edge of the opening 21 in the figure and the outer conductors 4, 4, 4 are bonded together. It is bonded with an ordinary epoxy adhesive 23 according to the requirements. The area near the upper edge of the opening 21 in the figure is near the open end of the resonator 1, and the outer conductor 4 and the main case 10 must be electrically connected well in this area. On the other hand, since the area near the lower edge of the opening 21 in the figure is near the short-circuited end of the resonator 1, there is no problem even if an insulating adhesive is used in this area. In addition, 24, 24, 24 are main case 1
Insert the screws into the screw holes 24, 24, 24 until the adhesives 22, 23 harden using the screw holes provided in the holes 11, 1.
Temporarily fix it within 1 and 11. After curing, remove the screws. Thereafter, at least both the opening 21 and the accommodation hole 11 are covered with a suitable cover.

The present invention is an application of the connection structure between the case and the resonator in the above-mentioned band-pass filter to a band-elimination filter, and FIGS. 5 and 6 show a band-elimination filter that is an embodiment of this invention. The main case 50 has almost the same structure as the main case 10, except that an opening 21 is provided in the recess 51 to accommodate coaxial cables 60, 61 and a metal plate 70, which will be described later. On the other hand, resonators 1, 1,
One electrode (lower electrode) of a capacitor 12 is connected to the tip of the inner conductor on the open end side of the capacitor 1 . The coaxial cables 60, 61 are made of semi-rigid cables having a length of 1/4 wavelength and folded into a loop shape. Since the main case 50 cannot be soldered, four holes are provided in the solderable metal plate 70, and the center lines 62, 63 of the cables 60, 61 and both ends of the insulators 64, 65 of the cables 60, 61 are inserted into the holes. is inserted, and the outer conductor of the semi-rigid cable is soldered to the metal plate 70, and the semi-rigid cable is electrically and mechanically attached to the main case 50 with screws 80, 81.
The main case 50 is provided with a hole, through which the tips of the center lines 62, 63 of the cables 60, 61 and the tips of the insulators 64, 65 are inserted into the accommodation hole 11,
It comes out in 11,11. A wire 91 connected to the center conductor of the input coaxial connector 16 is connected to the other electrode (upper electrode) of the capacitor 12 of the first stage resonator 1.
and one end of the center line 62 of the cable 60 is connected to the capacitor 1 of the second stage resonator 1.
The other end of the center line 62 of the cable 60 and the center line 63 of the cable 61 are connected to the other electrode (upper electrode) of the cable 60.
One end of the resonator 1 is connected to the final stage resonator 1.
The other electrode (upper electrode) of the capacitor 12 has a wire 9 connected to the other end of the center line 63 of the cable 61 and the center conductor of the output coaxial connector 20.
2 are connected. As in the previous example, at least both openings of the recess 51 and the accommodation hole 11 are covered with appropriate covers.

As is clear from the above examples, with this invention, the dielectric coaxial TEM resonator and the case can be securely fixed with the minimum amount of conductive adhesive, and the work efficiency is high, reducing the cost of the product. In addition, since the coaxial cable is bent into an arbitrary shape and accommodated in the recess created in the structure for fixing the resonator to the case, conventionally,
Effective for band rejection filters that are difficult to downsize.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a general dielectric coaxial TEM resonator, Figures 2 to 4 are diagrams showing a bandpass filter in the process of establishing the present invention,
3 is a side view thereof, FIG. 4 is a bottom view thereof, and FIGS. 5 and 6 are a side view and a plan view, respectively, showing a band rejection filter according to an embodiment of the present invention. . In the figure, 1 is a 1/4 wavelength dielectric coaxial TEM resonator, 4 is an outer conductor, 10 and 50 are main cases (conductor blocks), 11 is a housing hole, 21 is an opening, 22 is a conductive adhesive, and 60 is a housing hole. , 61 are coaxial cables.

Claims (1)

[Scope of utility model registration request] A dielectric coaxial TEM resonator, in which a solid dielectric exists between the inner and outer conductors, is fitted into a housing hole provided in a conductor block, and a part of the inner wall surface of the housing hole and a portion of the conductor block are inserted into the conductor block. Forming an opening that communicates with one main surface, the dielectric coaxial
Exposing the outer conductor of the TEM resonator through the opening,
The edge of the opening and the outer conductor near the open end of the resonator are adhered with a conductive adhesive, and a coaxial cable connecting the center conductors of the resonator is housed near the opening. band-stop filter.