JPH0371801B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the structure of an ultra-high frequency filter formed by striplines.

[Conventional technology]

To receive microwaves in a wide frequency band used in radar, these microwaves are passed through multiple ultra-high frequency filters with different wave frequencies.
A commonly used method is to convert the resulting microwaves of each frequency into an intermediate frequency using a local oscillator. At this time, a plurality of ultra-high frequency filters are connected and wired to each other on the same stripline plane or by coaxial cables or the like.

Such a super high frequency filter is formed on a dielectric substrate using strip lines. In this case, the capacitive element constituting the ultra-high frequency filter can be obtained by widening the stripline pattern width, and the inductance can be obtained by narrowing the stripline pattern width. Furthermore, it is well known that a series capacitive element is formed by overlapping strip lines with a dielectric substrate interposed therebetween.

[Problem that the invention seeks to solve]

Incidentally, it is possible to downsize a microwave receiver by forming an ultra-high frequency filter using striplines, but as mentioned above, it is possible to downsize the microwave receiver by using connection wiring to connect multiple ultra-high frequency filters. This has led to the problem that it may be difficult to miniaturize the microwave receiver.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a structure of an ultra-high frequency filter that facilitates miniaturization of a microwave receiver.

[Means for solving problems]

Therefore, the present invention includes a lower metal plate, a lower dielectric substrate arranged above the lower metal plate at a predetermined distance from the lower metal plate, and having an ultra-high frequency filter formed by lower strip lines on the lower surface thereof. ,
an intermediate metal plate disposed above the lower dielectric substrate at a predetermined distance from the lower dielectric substrate; an intermediate metal plate disposed above the intermediate metal plate at a predetermined interval from the intermediate metal plate; an upper dielectric substrate on which an ultra-high frequency filter is formed by an upper strip line; an upper metal plate disposed above the upper dielectric substrate at a predetermined distance from the upper dielectric substrate; In the structure of an ultra-high frequency filter having a strip line and a connection member for electrically connecting the lower layer stripline, a position facing the starting end of the lower layer stripline of the lower layer dielectric substrate and an upper layer stripline of the upper layer dielectric substrate; A predetermined hole of the same size is provided at a position facing the end portion of the lip line, and a hole of the same size is provided at a position corresponding to the hole drilling position of the upper and lower dielectric substrates of the intermediate layer metal plate, which is larger than the hole of both dielectric substrates. A center conductor that connects the upper and lower strip lines electrically through holes provided in the upper and lower dielectric substrates and the middle metal plate, and a center conductor that connects the upper and lower strip lines through holes provided in the upper and lower dielectric substrates and the middle metal plate; A cylindrical dielectric body to be fitted and inserted, having shoulders on both end faces that abut the lower surface of the upper dielectric substrate and the upper surface of the lower dielectric substrate, respectively. a protrusion that penetrates the body substrate and comes into contact with the lower surface of the upper metal plate and the upper surface of the lower metal plate;
By providing a connecting member formed of a dielectric material integrally formed to cover the center conductor,
This solves the above problems.

[Effect]

The structure of the ultra-high frequency filter having the above configuration is such that a lower metal plate, a lower dielectric substrate, a middle metal plate, an upper dielectric substrate, and an upper metal plate are stacked at predetermined intervals, and the upper dielectric substrate is laminated. The protruding part from the hole contacts the lower surface of the upper metal plate, the protruding part from the hole of the lower dielectric substrate contacts the upper surface of the lower metal plate, and the distance from the lower surface of the lower dielectric substrate to the upper surface of the lower dielectric substrate The upper layer stripline and the lower layer stripline are connected by a center conductor coated with a dielectric material whose portion can be inserted into a hole in the intermediate layer metal plate.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of the structure of an ultra-high frequency filter according to the present invention, in which FIG. 1a is a side view and FIG. 1b is a side view.
is a front view. In FIG. 1, 1 is a lower metal plate, 2 is a lower dielectric substrate disposed above the lower metal plate 1 at a predetermined distance from the lower metal plate 1, and 3
2a is a lower layer strip line forming an ultra-high frequency filter formed on the lower surface of the lower dielectric substrate 2;
4 is a hole of a predetermined size drilled at a position facing the starting end of the lower layer stripline 3, and 4 is interposed between both ends of the lower surface of the lower dielectric substrate 2 and both ends of the upper surface of the lower metal plate 1. A spacer 5 is a middle layer metal plate disposed above the lower dielectric substrate 2 at a predetermined distance from the lower dielectric substrate 2, and 5a is a spacer bored at a position corresponding to the hole drilling position of the lower dielectric substrate 2. A hole larger than the hole 2a of the lower dielectric substrate 2 provided, 6 a spacer interposed between both ends of the lower surface of the middle layer metal plate 5 and both ends of the upper surface of the lower dielectric substrate 2, 7 a middle layer metal plate An upper layer dielectric substrate is placed above 5 at a predetermined distance from the middle layer metal plate 5, 8 is an upper layer strip line forming an ultra-high frequency filter formed on the upper surface of the upper layer dielectric substrate 7, and 7a is an upper layer dielectric substrate. A hole 9 of the same size as the hole 2a of the lower dielectric substrate 2 is bored at a position facing the end of the stripline 8 and corresponding to the hole drilling position of the lower dielectric substrate 2. A spacer 10 interposed between both ends of the lower surface of the upper dielectric substrate 7 and both ends of the upper surface of the middle layer metal plate 5 is arranged above the upper dielectric substrate 7 at a predetermined distance from the upper dielectric substrate 7. 11 is a spacer interposed between both ends of the upper surface of the upper dielectric substrate 7 and the upper metal plate 10; 12 is a connecting member connecting the upper layer stripline 8 and the lower layer stripline 3; It is. As shown in FIG.
2a and a dielectric 12 covering the center conductor 12a.
It is composed of b. The center conductor 12a is fitted into the hole 7a of the upper dielectric substrate 7, the hole 5a of the middle metal plate 5, and the hole 2a of the lower dielectric substrate 2,
The upper end is connected to the upper layer stripline 8, and the lower end is connected to the lower layer stripline 3. In addition, the dielectric 12b, excluding the part necessary for connecting the center conductor 12a to the upper stripline 8, has a protruding part from the hole 7a of the upper dielectric substrate 7 in contact with the lower surface of the upper metal plate 10, and the center conductor 12
The protruding portion of the lower dielectric substrate 2 from the hole 2a contacts the upper surface of the lower metal plate 1, except for the portion necessary for connecting the lower dielectric substrate 2 to the lower stripline 3, and the portion protruding from the lower surface of the upper dielectric substrate 7 Lower dielectric substrate 2
The portion up to the upper surface of the metal plate 5 has a cylindrical shape that can be inserted into the hole 5a of the middle layer metal plate 5.

The microwave propagated through the upper stripline 8 is transmitted from the terminal end of the upper stripline 8 to the lower stripline 3 via the center conductor 12a.
The signal is propagated to the starting end of the strip line 3, and is further propagated through the lower stripline 3.

Note that the upper layer stripline 8 and the center conductor 12
The connection to a and the connection between the lower stripline 3 and the center conductor 12a are made by soldering or the like. Furthermore, Teflon (registered trademark) or the like is used as the material of the dielectric 12b.

In this embodiment, a two-layer ultra-high frequency filter has been described, but the present invention is not limited to this, and an ultra-high frequency filter having three or more layers may be configured.

〔Effect of the invention〕

As explained above, according to the present invention, the lower metal plate, the lower dielectric substrate, the middle metal plate, the upper dielectric substrate, and the upper metal plate are stacked and arranged at predetermined intervals, and the upper dielectric substrate A center conductor that is inserted into the hole, the hole in the middle layer metal plate, and the hole in the lower dielectric substrate, and is connected to the upper layer stripline and the lower layer stripline. The protruding portion from the hole in the body substrate contacts the lower surface of the upper metal plate, the protruding portion from the hole in the lower dielectric substrate contacts the upper surface of the lower metal plate, and the lower dielectric substrate is exposed from the lower surface of the upper dielectric substrate. By connecting the upper layer stripline and the lower layer stripline with a connecting member whose part up to the top surface is made of a dielectric material that can be inserted into a hole in the middle layer metal plate, a stacked ultra-high frequency filter can be formed. Therefore, it is possible to realize miniaturization of a microwave receiver using such an ultra-high frequency filter structure.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the structure of an ultra-high frequency filter according to the present invention, and FIG. 2 is a perspective view of the members shown in FIG. 1. 1... Lower layer metal plate, 2... Lower layer dielectric substrate, 3, 8
... Stripline, 4, 6, 9, 11... Spacer, 5... Middle layer metal plate, 7... Upper layer dielectric substrate, 10
...upper layer metal plate, 12... connection member.

Claims (1)

[Scope of Claims] 1. A lower metal plate, and a lower dielectric body disposed above the lower metal plate at a predetermined distance from the lower metal plate, and having an ultra-high frequency filter formed by a lower strip line on its lower surface. a substrate, an intermediate metal plate disposed above the lower dielectric substrate at a predetermined distance from the lower dielectric substrate; and an intermediate metal plate disposed above the intermediate metal plate at a predetermined distance from the intermediate metal plate. an upper dielectric substrate on which an ultra-high frequency filter is formed by upper strip lines; an upper metal plate disposed above the upper dielectric substrate at a predetermined distance from the upper dielectric substrate; In the structure of an ultra-high frequency filter having a connection member that electrically connects the upper layer stripline and the lower layer stripline, a position of the lower layer dielectric substrate facing the starting end of the lower layer stripline, and the upper layer dielectric substrate Holes of the same predetermined size are provided at positions facing the end portions of the upper layer stripline, and holes of both dielectrics are provided at positions corresponding to the holes in the upper and lower dielectric substrates of the middle layer metal plate. a center conductor having a hole larger than the hole in the body substrate and electrically connecting the upper and lower strip lines through the holes provided in the upper and lower dielectric substrates and the middle metal plate; A cylindrical dielectric that is inserted into a hole in a middle layer metal plate, and has shoulders on both end faces that abut the lower surface of the upper dielectric substrate and the upper surface of the lower dielectric substrate, respectively, and having protrusions that penetrate the upper and lower dielectric substrates and abut on the lower surface of the upper metal plate and the upper surface of the lower metal plate, respectively;
A structure of an ultra-high frequency filter, comprising a connecting member formed of a dielectric material integrally formed to cover the center conductor.