JPH0420521B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is generally applicable to signal transmission systems in the microwave region, such as when configuring band pass filters and frequency synthesizers (branchers). The present invention relates to a dielectric resonator to be obtained, and particularly relates to an improvement that allows connection to an external circuit to be made extremely easily even when the dielectric resonator is mounted on a dielectric substrate commonly referred to as a printed circuit board.

[Prior Art] A dielectric resonator, as shown in FIGS. 6A and 6B, conventionally has a dielectric resonator that penetrates the inside of a dielectric column 1 with a rectangular or circular cross section in one direction. A through hole 3 is opened, one of the pair of end walls (the upper surface in the figure) where the dielectric hole 3 is open is left, and a suitable conductive material such as silver is deposited on the other surface by, for example, vapor deposition. In addition to the peripheral wall conductive surface 4 and the bottom wall conductive surface 5, a conductive material is also attached to the inner wall surface of the through hole 3 to form the center conductor 6.

In the diagram, the parts of the conductive surface to which this conductive material has adhered are shaded for convenience, and the parts where the material of the dielectric pillars is exposed (insulating surface parts) are marked with fine dot patterns. And so.

In the dielectric resonator having such a structure, as can be understood from the longitudinal section shown in FIG. 6C, the end of the center conductor 3 on which no conductive surface is formed is connected to the first terminal T ₁ Alternatively, it can be considered as a two-terminal element with the end of the peripheral conductive surface 4 as the second terminal _T2 , and in principle it is a coaxial line with one end short-circuited.
If the length is chosen to be about 1/4 of the frequency wavelength λ _g used,
As shown in FIG. 6D, this is substantially equivalent to a parallel resonant circuit of a capacitor and an inductor.

Of course, under actual usage conditions, the terminal _T1 on the center conductor side is generally used as the hot side terminal for frequency signal input/output, and the other terminal _T2 is used as the ground side as shown by the imaginary line. The reason why a dielectric is used in such a dielectric resonator 1 is that the length λ _g /4 of the dielectric column 1 is reduced to one square root of the dielectric constant with respect to the free space wavelength of the frequency used. This is to reduce Therefore, in principle, it can be said that a material with a higher dielectric constant is more preferable for the dielectric pillar, unless losses due to series resistance etc. are particularly considered.

However, in the past, this type of dielectric resonator, which was provided by the manufacturer to the assembler as a single circuit component, actually remained in the two-terminal structure as described above, and as a result, this type of dielectric resonator When attempting to construct a circuit system using a resonator, such as a bandpass filter, etc., all connections between the front and rear stages have to be C-coupled.

That is, as shown in FIG. 7, for example, a bandpass filter 7 having an appropriate number of stages (three stages in the illustrated case)
In the case of configuring a dielectric resonator 1, adjacent dielectric resonators are not only connected by the coupling capacitor Cc between the center conductors, but also connected to the terminals T _i and T _p on the external circuit side, respectively, to the dielectric resonator 1 at the extreme end. The connection to the center conductor 6 had to be similarly made via the coupling capacitor Cc.

[Problems to be Solved by the Invention] However, in the conventional two-terminal dielectric resonator, the coupling between the two stages before and after the resonator must be C-coupled, which means that the circuit design Moreover, it has become a major constraining factor, not only hindering the degree of freedom in design, but also causing serious problems in the physical structure or geometric dimensions of certain circuit systems.

For example, regardless of the number of stages, a pair of bandpass filters 7 (7 _-1 , 7 _-2 ) already configured as shown in FIG.
A duplexer (two-frequency synthesizer) as shown in
This can be seen when assembling.

That is, when considering two mutually different frequencies f ₁ and f ₂ and combining them into one line 8 or discriminatively separating them into each line 9 _-1 and 9 _-2 , the static configuration is the 8th line. As shown in figure A, the frequency f ₁
Bandpass filter 7 tuned _{to -1} and frequency
Similar bandpass filter tuned to f ₂ 7 _-2
are prepared, and their output terminals are coupled together at a coupling point d to form a single line 8. Of course, the terms input and output are merely expressions for convenience, and in principle, signals can be transmitted bidirectionally in this type of circuit, so in the diagram,
Each signal f ₁ and f ₂ is marked with a bidirectional arrow.

In such a configuration, as is well known, the impedance seen from the coupling point d to the bandpass filter _7-1 for the frequency _f1 is infinite at the frequency _f2 , and similarly from the coupling point d to the frequency f1, the impedance is infinite at the frequency f2. Ideally, the impedance when looking at the bandpass filter 7 _-2 side for ₂ should be infinite at frequency f ₁ , and even when it is actually commercialized to be installed in various devices, this condition is not met. Care will be taken to ensure that the following are met as much as possible. Otherwise, two-wave mixing problems will inevitably occur to varying degrees.

However, in such a circuit, if conventional dielectric resonators are unavoidable for the bandpass filters 7 _-1 and 7 _-2 , the impedance outside the band is generally belongs to the shaded zone 1 as a result of the C-bonding described above. Therefore, in order to satisfy the above frequency separation condition, the distributed line lengths 1 ₁ and 1 ₂ from each bandpass filter to the coupling point d must be along the chart outer circle, as shown by arrow F, It must be long enough to rotate clockwise to the infinity position.

In reality, even the length required for a half-circle on the chart is λ _g /4, so the synthesizer with the configuration shown in Figure 8A is long, and generally about (3/8) λ _g . It takes.

This has actually been one of the factors that hinders the miniaturization of conventional wireless devices equipped with this type of circuit system, such as car telephones and cordless telephones. This is because there is a constraint that a printed circuit board portion with a considerably large area must be provided for this distributed line.

However, as is clear from the above description, these drawbacks do not occur with respect to the mutual coupling of dielectric resonators inside the bandpass filter. In other words, in a circuit system that only needs to handle a single frequency, even if it is C-coupled, there is no drawback that the line length is restricted to the extent that it becomes a problem. However, this also means that even if the bandpass filters 7 _-1 and 7 _-2 have a single stage configuration, if they are used as a frequency synthesizer etc., the relationship with the coupling point d will change. This problem can occur similarly, and more specifically, it can also occur when three or more frequencies are separated or combined.

In contrast, conventionally, terminals on the external circuit side
There are also dielectric resonators of the type in which the lines connected to T _i and T _p are equivalently magnetically inductively coupled to the center conductor 6.

However, from a structural perspective, some of them connect the connection line to the external circuit directly to the center conductor, or some have a predetermined pattern formed on the center conductor itself. . Therefore, it is necessary to form a horizontal hole in the dielectric pillar 2 and adhere a conductive material therein, or to solder the end of the line from the external circuit to the central conductor portion formed in a predetermined pattern. First, the structure was complicated, and the workability was poor because the soldering work had to be done in a narrow hole.

On the other hand, as seen in FIG. 8 attached to Patent Application Publication No. 59-500198, as an improvement to the basic dielectric resonator 1 already described in accordance with FIG. 6 attached to this book, the surrounding wall conductive surface 4 is peeled off to expose the surface of the peripheral wall underneath, and in this area, one end is in contact with the end wall conductive surface 5 and extends upward to a height midway in the axial direction of the dielectric column 2. A dielectric resonator having a structure in which the free end of the line forms a strip line has also been proposed. Of course, this strip line is provided to achieve magnetic inductive coupling with the center conductor.

It is true that this structure is suitable to some extent when a coaxial cable is used for connection to an external circuit. Strip the outer sheath of the coaxial cable, solder the outer conductor to the ground point common to the end wall conductive surface of the dielectric resonator, and connect the center conductor to the strip line located halfway in the height direction of the dielectric column. This is because it is sufficient to solder the ends.

However, as mentioned above, in recent applied technologies for car phones, cordless phones, etc., strip lines patterned on printed circuit boards are also used for connection lines (wiring lines) with external circuits. Often used.

As is clear, the dielectric resonator having the conventional structure described above cannot be used for applications requiring such a wiring system. A separate line member is required to raise the strip line on the printed circuit board that extends from the external circuit to the middle of the height direction of the dielectric column, which increases the number of parts and assembly processes, and increases the cost. This will cause a heavy burden. In terms of characteristics, it is undesirable for another linear conductive member to be close to and parallel to the strip line along the peripheral wall in view of the generation of parasitic capacitance.

In view of the various problems of the various conventional structures, the present invention has been developed to sufficiently shorten the line length to the coupling point, even when used in the aforementioned two-wave or multi-wave combiner, for example. It also has a high degree of design freedom even when viewed as a single unit, and has a structure that allows easy connection with external circuits, especially when constructing a circuit that includes a dielectric resonator on a printed circuit board, making it truly practical. The purpose of this invention is to provide a dielectric resonator with excellent properties.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a dielectric resonator having the following configuration.

First, as a basic structure, consider a dielectric resonator as described with reference to FIGS. 6A and 6B. That is, a center conductor formed on the inner wall surface of a through hole that passes between a pair of end walls of a dielectric column in the axial direction, a circumferential wall conductive surface provided on a circumferential wall of the dielectric column, and one end of the center conductor. The object of the improvement is a dielectric resonator having an end wall conductive surface formed only on one end wall of the pair of end walls described above in order to electrically connect to the peripheral wall conductive surface. .

Next, for such a basic structure,
Add the following configuration requirements.

: A part of the peripheral wall is an area area, and an axial dimension from the middle of the axial length of the dielectric column to the peripheral wall edge in contact with the end wall where the end wall conductive surface is provided; A predetermined area region defined by a predetermined dimension along the circumferential direction, which is a direction around the peripheral wall, is a non-conductive surface region where the peripheral wall conductive surface is not formed.

: The non-conductive surface region has a central conductor extending parallel to the central conductor from one end side connected to the peripheral wall conductive surface to a free end opposite to the one end in the middle of the axial length. A strip line is formed that is magnetically inductively coupled to the

: The non-conductive surface region where the peripheral wall conductive surface is not formed is left between both circumferential edges of the strip line and the peripheral wall conductive surface.

: The non-conductive surface area where the peripheral wall conductive surface is not formed is also left between the free end of the strip line serving as a connection terminal with an external circuit and the end wall conductive surface facing the free end. .

However, in another aspect of the present invention, the main parts have the above-mentioned constituent feature groups as they are, and are also based on the same technical idea, but the above-mentioned constituent features are changed to the following constituent feature '. We also propose an alternative dielectric resonator.

': The free end of the strip line extends to the edge of the peripheral wall in contact with the end wall of the non-conductive surface area, and the end wall conductive surface provided on the end wall extends to the free end of the strip line. In order to avoid contact with the end, it is not provided in a predetermined area on the end wall and between the free end and the end wall.

[Operations and Effects] According to the dielectric resonator of the present invention, the connection with an external circuit is not limited to C-coupling as in the conventional case.
Since magnetic inductive coupling can be achieved from the newly provided line section to the center conductor, the aforementioned drawbacks associated with the C-coupling can be completely eliminated.

For example, when a frequency synthesizer similar to that shown in FIG. 8A is configured, the connection between the signal input or output terminal to the junction d and the dielectric resonator is magnetically inductively coupled, that is, M-coupled according to the present invention. If
In the Smith chart shown in FIG. 8B, the out-of-band impedance generally belongs to the shaded Zone 2.

Therefore, the line length to achieve infinite impedance when viewed from the coupling point d with respect to the frequency of the other party can be approximately λ _g /8 at most.
Compared to the conventional C-coupled circuit, the length is significantly shortened.

Furthermore, when looking at the dielectric resonator of the present invention as a structure for achieving such a structure, the strip line portion in which the signal terminal of the external circuit is provided at the free end and is magnetically inductively coupled to the center conductor is In the case of a dielectric resonator, it can be easily formed into any required dimensions according to the design by simply patterning when forming the peripheral conductive surface.

Moreover, the strip line extends from the midway in the axial direction of the dielectric column toward the end wall conductive surface, and the free end, which serves as the connection terminal for the external circuit, is close to the end wall conductive surface. Therefore, in response to recent demands, if the dielectric resonator of the present invention is assembled on a printed circuit board, the terminal of the strip line routed on the same printed circuit board can be connected to the strip on the dielectric resonator side. Even when it is necessary to electrically connect to a line, unlike the conventional example disclosed in the above-mentioned published patent publication, it is possible to connect from an external circuit by utilizing the thickness of the printed circuit board without having a separate line member. By making sure that the terminal of the strip line for wiring to an external circuit or external circuit is exactly at the height of the free end of the strip line of this dielectric resonator, only the soldering process at the end of the butt part is possible. You can get away with it.

In addition, when the free end of the strip line of this dielectric resonator is extended to the edge of the peripheral wall that is in contact with the end wall provided with the end wall conductive surface, the pin is axially outward from the free end. By simply standing up the shaped conductive member, it can be easily connected to the wiring strip line provided on the back side of the printed circuit board.

On the other hand, even under similar circumstances, in the conventional example disclosed in the published patent publication mentioned above, the material passes through the thickness of the printed circuit board from the back side of the printed circuit board and protrudes further into the space, and the It requires a conductive member that extends to a height position, which makes the structure and wiring process very complicated, and also makes it difficult to obtain desirable results in terms of electrical characteristics.

[Example] FIG. 1 shows an equivalent circuit diagram realized by the dielectric resonator of the present invention.

In the dielectric resonator 10 of the present invention, similar to the explanation regarding the conventional two-terminal dielectric resonator,
If we conceptually attach terminals T ₁ and T ₂ to a parallel resonant circuit, there is a new line section 11 that is magnetically coupled (M-coupled) to the inductor in the parallel resonant circuit, and a third terminal T ₃ can be assumed.

Therefore, if the conventional element is a two-terminal type, the element of the present invention can be compared with a three-terminal type. However, of course, the term "terminal" refers to a conceptual signal input or output part, and it does not necessarily have to be defined as a specific point part in terms of physical structure. As is clear from FIG. 1, the equivalent circuit achieved by the present invention is not of a so-called autotransformer type, but of a separately wound coil type.

However, as seen in the prior art example mentioned above, there have been some specific examples of methods for forming the line portion 11 that is M-coupled to the center conductor, but in the present invention, In accordance with the stated objectives and for their realization, we provide a structure as found in the following examples.

FIG. 2 shows a first embodiment of a dielectric resonator 10 according to the invention.

As a convention, among the symbols used in each of the drawings from FIG. 2 to FIG. Components that may be the same or similar to those of the dielectric resonator are shown. Further, the direction in which the central conductor extends is defined as the axial direction, and the direction around the peripheral conductive surface is defined as the circumferential direction.

As shown in FIG. 2A or B, in the dielectric resonator 10 of the present invention, first, like the dielectric resonator 1 having the conventional basic structure shown in FIG.
It has a dielectric column 2 made of a suitable dielectric material and having a suitable cross-sectional shape (generally a rectangular cross-section or a circular cross-section). A conductive material is deposited by vapor deposition or the like, thereby forming several wall conductive surfaces 4, end wall conductive surfaces 5, and a center conductor 6.

However, even on the upper end wall surface of the dielectric column 2 on which no conductive material is deposited, a certain distance is placed so that it does not electrically contact the opening on this surface of the center conductor 6. If so, this does not prevent the conductive material from being vapor-deposited also on a part of this upper end wall surface, if necessary.

However, in order to form a new line section 11 M-coupled to the center conductor 6 according to the invention, this second
In the embodiment shown in the figure, a peeled part 12 is formed by removing the conductive material from one side of the four-sided peripheral conductive surface 4, and a strip line 13 is formed surrounded on three sides by this peeled part.

More specifically, in this first embodiment,
First, the peripheral wall end edge, which is a part of the peripheral wall 4 and is in contact with the end wall where the end wall conductive surface 5 is provided from the middle of the axial length of the dielectric column 2 (in the figure, the lower side The peeling portion 12 is provided as a predetermined area defined by an axial dimension up to the end edge of the circumferential wall 4 and a predetermined dimension along the circumferential direction, which is the direction around the peripheral wall 4 .

In this peeled portion 12, which is a non-conductive surface region, it electrically contacts the peripheral wall conductive surface 4 at its upper end position (that is, a position midway in the axial direction of the dielectric column), but from that position to the center The free end, which is the tip extending downward in the figure parallel to the conductor 6, is
A strip line 1 having an axial length that does not reach the lower end edge of the peripheral wall, and which is not connected to the peripheral wall conductive surface 4 in the plane on both sides in the circumferential direction.
3 is formed, and this is used as the line portion 11 that is M-coupled to the center conductor 6.

In such a case, the easiest way to understand this in comparison with the conventional line is to assume a third signal terminal _T3 at the free end of this line portion 11 (strip line 13) (this is shown in the cross-sectional view of Fig. 2C). ), and its equivalent circuit is shown in Figure 1, and for the inductor of the parallel resonant circuit,
M-coupling defined by the degree of coupling according to the length and width of the strip line 13 can be realized.

Furthermore, what is characteristic from a structural point of view is that the free end of the strip line 13, where the third signal terminal _T3 can be set, extends to a position extremely close to the end wall conductive surface 5, as shown in FIG. As seen in the application example shown in B, when the wiring line between the external circuit is a strip line patterned on a printed circuit board, when this dielectric resonator is assembled on the same printed circuit board. Next, by utilizing the thickness of this printed circuit board, the strip line that is the wiring line is connected to the strip line 1 of the dielectric resonator.
By simply aligning the heights with the free ends of 3 and soldering them, there is no need for a separate conductive member, and there is no need to stand the conductive member in the air and extend it. Electrical connection processing can be easily performed. Naturally, the electrical characteristics are not particularly impaired either.

A strip line 13 as line section 11 M-coupled to the center conductor and having similar structural features is
It can also be configured as shown in FIGS. 3A and 3B.

The difference from the embodiment shown in FIG. 2 is that the peripheral wall 4
The point is that the free wire of the strip line 13 provided in the upper non-conductive surface area (separated part) 12 is extended to the edge of the peripheral wall 4 that is in contact with the end wall with the single-wall conductive surface 5. , Therefore, so that this free end does not come into electrical contact with the end wall conductive surface 5,
A peeling portion 14 having a predetermined area and positionally aligned with the peeling portion 12 is also provided on the end wall conductive surface 5 .

Even in this case, as is clear from the cross-sectional configuration shown in FIG.
A configuration similar to the M-coupling shown in the figure can be satisfied.

However, as seen in the application example described later, the take-out position of the third signal terminal _T3 is set to the end wall conductive surface 5.
Even under the condition that it is close to , the ability to change as described above has the effect of making the design advantageous in terms of implementation. This is because it is only necessary to select an appropriate one, and if the effective length is the same, the embodiment shown in FIG. The area area can be reduced.

The conductor resonators 10 of the present invention manufactured as described above can be used to construct a bandpass filter 7, for example, as shown in FIG. 4.

In each of the illustrated cases, a three-stage configuration is illustrated, and the middle dielectric resonator 1 is a two-terminal type exclusively for C coupling of the conventional configuration, and the dielectric resonators 10 of the present invention on both sides,
10, the center conductors are C-coupled with each other by a capacitor Cc.

However, in the case of FIG. 4A, the dielectric resonators 10, 10 of the present invention provided at both ends use the structure of the embodiment shown in FIG. 3, and have a terminal T as a ground terminal. ₂ is configured as a metal piece 30 extending downward, and a third terminal _T3 related to signal input/output is similarly provided with a metal pin 31. This structure clearly represents an example suitable for construction on a suitable printed circuit board.

Metal pieces 30 as ground conductors are provided at the four corners of the overall structure as shown in the figure, and these metal pieces 30 and signal terminals are connected to each other.
By drilling an opening through which the metal pin 31 ( _T3 ) passes through in a predetermined part of the printed circuit board, it is easy to establish continuity with the signal transmission strip line pattern and ground pattern formed on the back side of the printed circuit board. Alternatively, this bandpass filter structure can also be physically fixed onto the printed circuit board by bending the metal piece 30 that is passed through the back surface of the printed circuit board to establish ground conduction.

FIG. 4B shows a case where the dielectric resonator of the present invention shown in FIG. 2 is used as a dielectric resonator at both ends. An M-coupling similar to the structure shown in FIG. If used as a signal terminal _T3 , it can be easily attached to the printed circuit board and connected to other patterns on the printed circuit board. That is, the distance between the free end of the strip line 13 provided on the peripheral wall of the present dielectric resonator and the peripheral wall edge (or end wall conductive surface 15) facing the free end is defined as: By matching the thickness of the printed circuit board 18 on which the wiring strip line 19 is mounted, the electrical connection between the strip lines 13 and 19 can be easily made by simply butting and soldering, as shown in FIG. 4B. And it can be done reliably.

Of course, for example, in the case of a single-stage or two-stage configuration, coexistence with the dielectric resonator 1 of the conventional configuration is avoided,
A configuration using only the dielectric resonator 10 of the present invention is possible, and conversely, in the case of a configuration with three or more stages, the M-coupled dielectric resonator 10 of the present invention can also be used as the dielectric resonator in the intermediate stage. You can also use Furthermore, it is naturally possible to utilize the dielectric resonator of the present invention in a synthesizer that handles multiple types of frequencies.

Furthermore, the line portion 11 added according to the present invention and M-coupled to the center conductor can itself be expanded into a plurality of lines. For example, in each of the illustrated embodiments, it is also possible to form another line section 11 on a surface diametrically opposite to the surface on which the line section 11 is formed.

Note that if two bandpass filters (7 _-1 , 7 _-2 ) as shown in FIG. 4 are used, a frequency synthesizer (branching filter 9) shown in FIG. 5 can be obtained. As is clear, this application example uses the dielectric resonator of the present invention, the equivalent circuit of which is shown in FIG.
This corresponds to the illustrated configuration example.

In such a frequency synthesizer, as already explained in the operation section, the out-of-band impedance generally belongs to the shaded zone 2 in the Smith chart shown in FIG. The lengths 1 ₁ and 1 ₂ of the distributed lines leading to 7 _-1 and 7 _-2 are approximately λ _g /8 at most in order to realize infinite impedance when viewed from the junction point d with respect to the frequency of the other party. This is significantly shorter than the conventional C-junction circuit, which promotes the miniaturization of equipment equipped with this type of circuit and contributes to the effective use of space inside the aircraft.

Furthermore, in any of the embodiments described above,
In order to form the line portion 11 that is M-coupled with the center conductor, the insulating portions provided around the line portion 11 are named “separated portions”; however, these peeled portions 12,
14 is formed by actually removing the conductive material from each conductive surface portion over the required area, as well as by not attaching any conductive material to the area planned as the peeled portion from the beginning. It is a concept that also includes. Therefore, in order to unify the gist of the present invention, the region corresponding to such a peeled portion can be referred to as a "non-conductive surface region" as mentioned above.

[Brief explanation of drawings]

FIG. 1 is an equivalent circuit diagram of the dielectric resonator of the present invention, FIGS. 2 and 3 are explanatory diagrams of each embodiment of the dielectric resonator of the present invention showing specific structural examples, and The figure is an explanatory diagram of a configuration example of a bandpass filter using the dielectric resonator of the present invention, FIG. 5 is a schematic configuration diagram of an application example in which the bandpass filter shown in Figure 4 is applied to a frequency fraction synthesizer, and FIG. 7 is an explanatory diagram of a conventional two-terminal dielectric resonator exclusively for C-coupling.
The figure is an explanatory diagram of a conventional bandpass filter configured using a two-terminal dielectric resonator dedicated to C-coupling, and Figure 8 is an illustration of a conventional frequency synthesizer to which the bandpass filter shown in Figure 7 is applied. This is an explanatory diagram based on the conceptual structure and Smith Chart. In the figure, 1 is a conventional two-terminal dielectric resonator exclusively for C coupling, 2 is a dielectric column, 3 is a through hole, 4 is a peripheral wall conductive surface, 5 is an end wall conductive surface, 6 is a center conductor, 7, 7 _-1 ,
7 _-2 is a bandpass filter, 8 is a common line in a frequency synthesizer (branching filter), 9 _-1 and 9 _-2 are dedicated lines for each frequency, and 10 is a three-terminal type capable of magnetic coupling according to the present invention. A dielectric resonator, 11 is a line portion magnetically coupled to the center conductor, 12 and 14 are peeled portions or non-conductive surface areas, 13 is a strip line provided in the peeled portion or non-conductive surface area of the dielectric resonator, and 19 is a strip line provided in the peeled portion or non-conductive surface area. A strip line 18 is provided on the surface of a dielectric substrate (printed circuit board), and is a dielectric substrate or printed circuit board.

Claims (1)

[Scope of Claims] 1. A central conductor formed on the inner wall surface of a through hole extending axially between a pair of end walls of a dielectric column, a peripheral conductive surface provided on a peripheral wall of the dielectric column, In order to electrically connect one end of the center conductor to the peripheral conductive surface,
In a dielectric resonator comprising an end wall conductive surface formed only on one end wall of the pair of end walls; An axial dimension from the middle of the axial length to an end edge of the peripheral wall that contacts the end wall where the end wall conductive surface is provided, and a predetermined dimension along the circumferential direction that is the direction around the peripheral wall. The defined predetermined area area is a non-conductive surface area that does not form the peripheral wall conductive surface; A strip line extending parallel to the center conductor toward a free end opposite to the one end and magnetically inductively coupled to the center conductor is formed; and between both circumferential edges of the strip line and the conductive surface of the peripheral wall. While leaving the non-conductive surface area where the peripheral wall conductive surface is not formed; and also between the free end of the strip line that serves as a connection terminal to an external circuit and the end wall conductive surface facing the free end. , leaving the non-conductive surface area where the peripheral wall conductive surface is not formed. 2. A central conductor formed on the inner wall surface of a through hole that passes between a pair of end walls of a dielectric column in the axial direction, a peripheral conductive surface provided on a peripheral wall of the dielectric column, and one end of the central conductor. for electrically connecting to the peripheral wall conductive surface;
In a dielectric resonator comprising an end wall conductive surface formed only on one end wall of the pair of end walls; An axial dimension from the middle of the axial length to an end edge of the peripheral wall that contacts the end wall where the end wall conductive surface is provided, and a predetermined dimension along the circumferential direction that is the direction around the peripheral wall. The defined predetermined area area is a non-conductive surface area that does not form the peripheral wall conductive surface; A strip line extending parallel to the center conductor toward a free end opposite to the one end and magnetically inductively coupled to the center conductor is formed; and between both circumferential edges of the strip line and the conductive surface of the peripheral wall. while leaving the non-conductive surface region where the peripheral conductive surface is not provided; the free end of the strip line extending to an edge of the peripheral wall in contact with the end wall of the non-conductive surface region; The end wall conductive surface, which is connected to the strip line, is arranged so as not to contact the free end of the strip line.
A dielectric resonator characterized in that it is not provided in a predetermined area on the end wall and between the free end and the free end.