JPH0878908A - High frequency filter - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] The purpose is to obtain a high-frequency filter that achieves a predetermined effect in a small area with respect to a set resonance frequency. Furthermore, a high frequency filter whose coupling degree can be easily adjusted is obtained. [Structure] At least first and second fan-shaped inner conductors 21a and 21b are provided on the same dielectric, and a radially inner surface of the inner conductor is connected to an outer conductor 22 which is connected to a ground conductor. The input / output terminals 23 are provided on the outer sides of the first and second inner conductors in the radial direction.
a and b were directly or indirectly connected, and further, the first and second fan-shaped inner conductors were arranged radially on the same circumferential surface on the dielectric body at a predetermined angle from the outer conductor. Furthermore, the first and second inner conductors each have a T-shaped inner conductor whose outer portion in the radial direction is longer in the circumferential direction than the inner portion, and these T-shaped portions which are long in the circumferential direction are required. An electric field coupling surface was formed by abutting with a distance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is mainly applied to VHF band,
The present invention relates to a high frequency filter used in the UHF band and the microwave band.

[0002]

2. Description of the Related Art FIG. 14 is a schematic structural view showing a conventional high frequency filter disclosed in Japanese Patent Publication No. 2-11163. In the figure, 1a and 1b are dielectric substrates, and 2a to 4a.
Is an inner conductor formed by closely adhering a conductor film to one surface of the dielectric substrate 1a, 5a is an outer conductor formed by adhering a conductor film to the entire other surface of the dielectric substrate 1a, and 5b is a dielectric material Board 1
an outer conductor formed by closely adhering a conductor film to one surface of b, 6 to 8
Is a triplate line resonator including dielectric substrates 1a and 1b, inner conductors 2a to 4a, and outer conductors 5a and 5b.
Reference numeral 9a denotes a coupling amount adjusting groove provided by engraving the dielectric substrate 1a in the central portion between the inner conductors 2a and 3a and 3a and 4a.
b is a groove for adjusting the coupling amount, which is provided by engraving the dielectric substrate 1b in the central portion between the inner conductors 2b and 3b and 3b and 4b.
Reference numerals 11 and 11 denote input / output lines whose inner conductors are directly connected to the side surfaces of the inner conductors 2a and 4a, respectively. The dielectric substrates 1a and 1b are overlapped and bonded so that the grooves 9a and 9b face each other and overlap. Each of the inner conductors 2a to 4a is set to about 1/4 wavelength, and one end thereof is connected to the side surfaces of the dielectric substrates 1a and 1b and short-circuited with 5a and 5b. Therefore, the resonators 6 to 8 are
It is a quarter wavelength resonator. In the dielectric substrate 1a, the longitudinal direction of the inner conductor 2a is set longer than that of the dielectric substrate 1b. By arranging the dielectric substrates 1a and 1b so that the short-circuited ends of the resonators 6 to 8 are aligned, Conductor 2a ~
The open end side of 4a is exposed.

Next, the operation will be described. Resonator 6 ~
8 are adjacent to each other and are magnetically coupled to each other due to the effect of the grooves 9a and 9b, and the coupling amount is adjusted by the depth of the grooves 9a and 9b and the distance between the adjacent inner conductors. Further, the input / output coupling amount is adjusted by changing the connection positions of the inner conductors of the input / output lines 10 and 11 and the inner conductors 2a and 4a.

Now, by trimming the exposed portions of the inner conductors 2a to 4a on the open end side to adjust the lengths of these inner conductors, all the resonators 6 to 8 have the same frequency, for example, f _0.
At the frequency f ₀ , the resonators 6 to 8 in the resonance state are strongly coupled to each other,
The incident light on the input / output line 10 is guided to the resonator 6, passes through the resonators 7 and 8, and is output from the input / output line 11. However, at frequencies other than f ₀ , the coupling between the resonators 6 to 8 is very weak, and most of the electric power of the incident wave to the input / output line 10 or 11 is reflected. Thus, the stripline filter shown in FIG. 13 has a function as a bandpass filter.

As a modification of the strip line, instead of a strip line having a constant impedance, the strip width on the short-circuit end side is narrowed and the strip width on the open end side is widened into a T shape, that is, on the short-circuit short side. There is also an example in which the impedance Z ₂ is made larger than the impedance Z ₁ on the open end side. However, even in this example, the shape is a simple T-shaped parallel line.

[0006]

Since the conventional stripline filter is constructed as described above, in order to obtain the coupling between the resonator 6 and the resonator 7 and between the resonator 7 and the resonator 8, Since the grooves 9a and 9b need to be provided on the dielectric substrate by machining, there is a problem that the processing becomes complicated. Further, such a structure has a problem that a relatively large area is required to obtain the resonance frequency.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a high-frequency filter which has a small area for the same frequency, is easy to process, and is excellent in mass productivity. .

[0008]

In a high frequency filter according to the present invention, at least first and second fan-shaped inner conductors are provided on the same dielectric, and the inner surface of the inner conductor in the radial direction serves as a ground conductor. Connect to the outer conductor to be connected, and also to the above first and second
Input / output terminals are directly or indirectly connected to the outer side of the inner conductor in the radial direction, and the first and second fan-shaped inner conductors are separated from each other by a predetermined angle on the same circumferential surface on the dielectric body. It was installed radially as seen from the conductor.

Furthermore, each of the first and second inner conductors is a T-shaped inner conductor whose outer portion in the radial direction is longer in the circumferential direction than in the inner portion. The parts were separated by a required distance and abutted together to form an electric field coupling surface.

Furthermore, the electric field coupling surfaces of the T-shaped portions that are long in the circumferential direction of the first and second inner conductors are in contact with each other in the circumferential direction of the mating inner conductor and are also in contact with the circumferential direction. I have a face.

Furthermore, the outer conductor connecting the inner sides of the first and second inner conductors in the radial direction has a hollow center portion at the center of the inside.

Further, in the basic structure, the first and second inner conductors are provided on the same circumferential surface of the dielectric body, which is an intermediate surface for electric field coupling on the outer side in the radial direction of the first and second inner conductors. U-shaped third with the surface in contact with the straight line on both sides and the bottom in the circumferential direction
The inner conductor was added.

Further, in addition to the basic structure, a third inner conductor is provided on a plane opposite to the plane on which the first and second inner conductors are placed on the dielectric, and the third inner conductor is at least the above-mentioned first one. The second inner conductor and the second inner conductor are arranged so as to have a portion which is projected on the above-mentioned plane and overlaps on the outside in the radial direction.

Furthermore, the third inner conductor has a U-shape having a band-shaped portion which is projected and overlaps with the coupling surfaces of the first and second inner conductors facing each other.

In the high frequency filter according to the present invention, at least first and second fan-shaped inner conductors are provided on the same dielectric.
The inner surface of the inner conductor in the radial direction is connected to an outer conductor which is connected to the ground conductor, and the first and second fan-shaped inner conductors are separated from each other by a predetermined angle on the same circumferential surface on the dielectric. A resonator arranged radially from the outer conductor is provided, and the first and second resonators are provided on different surfaces of the dielectric from the first and second inner conductors.
A main line having input / output terminals is provided along the outer edge of the inner conductor in the circumferential direction, and the resonator and the main line have a desired degree of coupling on the circumferential surface of the resonator with the dielectric material sandwiched therebetween. It was given a structure.

Further, in order to set the degree of coupling between the resonator and the main line to a desired value, a plurality of protrusions are provided on outer circumferential edges of the first and second inner conductors of the resonator, The degree of bonding is changed depending on the number or length of the plurality of protrusions.

Furthermore, in order to set the degree of coupling between the resonator and the main line to a desired value, a plurality of protrusions are provided on the surface where the main line contacts the outer sides of the first and second inner conductors in the circumferential direction. , The degree of bonding is changed by the number or length of the plurality of protrusions.

Further, in the band elimination filter, the first
And the outer conductor connecting the inner side of the second inner conductor in the radial direction,
A hollow center was provided inside.

Further, in the basic structure, at least the first dielectric body having the first and second inner conductors and the first outer conductor having the hollow portion connecting the first and second inner conductors on the inner side in the radial direction thereof is mounted at least. The hollow portion of the outer conductor is provided with a second doughnut-shaped conductor surface on the side opposite to the inner conductor on the dielectric, and further with the first outer conductor and the second outer conductor.
The second conductor has a cylindrical conductor surface for connecting with the conductor and is in contact with the ground conductor provided on another second dielectric at the hollow portion.

Furthermore, the radial length of the first dielectric and the radial length of the second dielectric are different from each other.

In the high frequency filter according to the present invention, T-shaped fan-shaped inner conductors having at least first and second radially outer portions in the circumferential direction longer than the inner portion are provided on the same dielectric, In addition, the inner surface in the radial direction is connected to the outer conductor, which is connected to the ground conductor, and the inner conductors have a T-shaped upper portion that is long in the circumferential direction and talk with each other for a required distance to form an electric field coupling surface. The structure is such that the inner side in the direction is the magnetic field coupling surface, and the input / output terminals are directly or indirectly connected to the outer sides in the radial direction of the first and second inner conductors, and further the first and second fan-shaped inner conductors. Are radially arranged on the same circumferential surface of the dielectric body as seen from the outer conductor, and are separated by a predetermined angle. The pass frequency band is determined by the impedance of each inner conductor and the electric field coupling between the first and second inner conductors. It has a stop frequency determined by magnetic field coupling.

[0022]

In the high frequency filter according to the present invention, a signal input to one of the fan-shaped resonators is induced in the other fan-shaped resonator by the electric field and magnetic field coupling to give the characteristics of the high frequency filter. Due to the fan-shaped shape, the degree of coupling between electric field coupling and magnetic field coupling can be enhanced with a small shape.

Furthermore, although the input / output characteristics of signals, that is, the frequency characteristics, are the same, electric field coupling is further enhanced with a smaller shape.

Furthermore, although the input / output characteristics of signals, that is, the frequency characteristics are the same, the resonators are also coupled to each other in the circumferential direction, and the electric field coupling is further enhanced with a smaller shape.

Furthermore, although the signal input / output characteristics, that is, the frequency characteristics, are the same, the distance accuracy to the ground plane of the resonator is high.

Furthermore, although the input / output characteristics of signals, that is, the frequency characteristics are the same, the degree of electric field coupling of the resonator is further enhanced.

Furthermore, although the input / output characteristics of signals, that is, the frequency characteristics, are the same, the electric field coupling degree of the resonator is further enhanced.

Furthermore, although the input / output characteristics of signals, that is, the frequency characteristics are the same, the degree of electric field coupling of the resonator is further enhanced.

In the high frequency blocking filter according to the present invention, the resonance frequency of the fan-shaped resonator provided to be coupled to the main line is blocked to provide the characteristics of the high frequency blocking filter. Due to the fan-shaped shape, a predetermined characteristic can be obtained with a resonator having a small area.

Furthermore, the degree of coupling between the main line and the resonator is arbitrarily adjusted to obtain a desired degree of coupling.

Furthermore, the degree of coupling between the main line and the resonator is arbitrarily adjusted to obtain the desired degree of coupling.

Furthermore, although the signal input / output blocking characteristics, that is, the frequency characteristics are the same, the distance accuracy to the ground plane of the resonator becomes high. That is, the frequency accuracy is high.

The high-frequency filter according to the present invention has similar signal input / output characteristics, that is, frequency characteristics, but can be easily connected to the ground plane of the resonator. That is, the workability becomes high.

Further, although the signal input / output characteristics, that is, the frequency characteristics are the same, the connection to the resonator, the main line, and the degree of coupling can be easily adjusted. That is, the workability becomes high.

In the high frequency filter according to the present invention, a signal input to one of the fan-shaped resonators resonates and passes at a frequency determined by the impedance of each, and a small shape provides a large degree of coupling to pass the signal. In the vicinity of frequency, a characteristic appears that has a stop frequency determined by its coupling impedance.

[0036]

【Example】

Example 1. 1 is a diagram showing a configuration of a high frequency filter according to a first embodiment of the present invention. FIG. 1A is a plan view and FIG.
(B) is a perspective view. In the figure, 21a and 21b are inner conductors, 22 is an outer conductor, and 23a and 23b are input / output terminals. The inner conductor 21a and the outer conductor 22 form a resonator 1 20a, and the inner conductor 21b and the outer conductor 22 form a resonator 2 20b.
Is configured. The resonator 1 20a and the resonator 2 20b are
The common outer conductor 22 is short-circuited, and the outer conductor 22 is
The upper outer conductor of 5a and the lower outer conductor of 25b are short-circuited and grounded. The resonator 1 20a and the resonator 2 20b are 2
6b is formed on the same plane as the second layer dielectric. The outer conductor 22 is connected to the ground planes 25a and 25b as outer conductors by the short-circuit portion 24. The outer conductor 2
5a is formed on the dielectric 26a of the first layer, and the outer conductor 25
b is formed on the third layer dielectric 26c. As will be described later, these are formed in multiple layers to form a filter.
The signal enters the input / output terminal 23a and is output from the input / output terminal 23b. The inner conductors 21a and 21b, the outer conductor 22, the input / output terminals 23a and 23b, etc. are formed as a thin film or a thick film on the dielectric substrate 26b, and are formed by photoetching or the like. Whereas a normal resonator is composed of a 1/4 wavelength band-shaped line, the resonator of the present embodiment has a fan shape and its ground plane, that is, the portion near the outer conductor has a high impedance, It has a shape in which the impedance becomes lower in the direction further away in the radial direction. Therefore, the total length may be shorter than 1/4 wavelength, and miniaturization can be achieved.

Next, the operation will be described. In the high frequency filter having the above structure, the resonator 1 20a and the resonator 2 20
When b resonates at the same frequency f ₀ , these two resonators 1
The resonator 2 and the resonator 2 are strongly coupled through the coupling of the fan-shaped side surfaces, and the signal transmitted to the input / output terminal 23a is guided to the other input / output terminal 23b. However, at frequencies other than f ₀ , the coupling between the resonators is weak, and most of the incident wave at the input / output terminals is reflected. Thus, the high frequency filter of FIG. 1 functions as a band pass filter. Resonator 1
The amount of coupling between the resonator 2 and the resonator 2 can be adjusted by changing the angle formed by the center lines of the resonators. Further, the resonance frequency can be easily changed by changing the lengths of the inner conductors 21a and 21b or changing the angle formed by the conductors of the fan-shaped inner conductor. In this way, it is possible to obtain the same resonance frequency with a shorter area, that is, with a smaller area as compared with the conventional band-shaped resonator. In addition, the outer conductor 25a, which is a ground plane,
25b may be configured such that either one is omitted and the outer conductor is provided only on one surface.

Example 2. FIG. 2 is a plan view showing the configuration of the high frequency filter according to the second embodiment. Specifically, it is formed by photo-etching as a thin film or a thick film on a dielectric substrate. In the figure, 31a is an upper inner conductor, 32a is a lower inner conductor, 3
Reference numeral 4 is a ring-shaped outer conductor, and 33a is an input / output terminal. The upper inner conductor 31a and the lower inner conductor 32a have a T-shaped resonator 1
30a is formed. Similarly, 31b is an upper inner conductor, 3
2b is a lower inner conductor, and 33b is another input / output terminal. The upper inner conductor 31b and the lower inner conductor 32b form a T-shaped resonator 230b. In this way, in the configuration in which the inner conductor is divided into two parts, the circumferential direction and the area of the upper inner conductor are widened, and the impedance is further lowered, the simple fan shape of FIG. More than anything
The resonance frequency can be lowered. That is, in order to obtain the same resonance frequency, the object can be achieved with a smaller shape.

In the configuration of FIG. 2, the lower inner conductor 32a
And 32b are mainly magnetic field couplings, and the coupling between upper inner conductors 31a and 31b is mainly electric field couplings.
It can be said that this structure further strengthens the electric field coupling. The resonance frequency can be adjusted by changing the radial length of the fan shape, the radial length of the upper inner conductor, and the angle formed by the conductor of each inner conductor. Similarly, the degree of coupling can be adjusted by changing the distance between the upper inner conductors and the distance between the lower inner conductors. The input / output terminals may be connected in the circumferential direction shown in FIG. 1 or from the outermost part in the radial direction shown in FIG. 2, or may be another method shown in the drawings of the following embodiments. Since the operation of this embodiment is similar to that of the first embodiment, detailed description will be omitted.

Example 3. FIG. 3 is a plan view showing the configuration of the high frequency filter of the third embodiment. The basic shape uses a T-shaped fan-shaped resonator. Therefore, the resonance frequency is the same as that in the second embodiment, but in this embodiment, the degree of electric field coupling is further strengthened. That is, in FIG. 3, the upper inner conductors 31c and 31d have an uneven surface as the shape of the electric field coupling surface thereof. Similarly, FIG.
In (b), the upper inner conductors 31e and 31f have a shape having an L-shaped electric field coupling surface. The input / output terminals are shown in Fig. 3.
In FIG. 3 (a), the resonator is indirectly input from the other surface of the dielectric through the dielectric, and in FIG. 3 (b), the resonator is indirectly input from 33e and 33f on the same plane on the dielectric. Is the format used. Since the operation of this embodiment is similar to that of the first and second embodiments, detailed description thereof will be omitted.

Example 4. FIG. 4 is a plan view showing the configuration of the high frequency filter according to the fourth embodiment. Although the structure has already been shown in FIGS. 2 and 3 of the second and third embodiments, the gist of this embodiment is that the outer conductor 34 has a hollow portion. By dropping the outer conductor 34 having the hollow portion to the ground plane by using another element, the outer conductor 34 can be easily used as the ground plane.

Example 5. FIG. 5 is a plan view showing the configuration of the high frequency filter of the fifth embodiment. The high-frequency filter shown in FIG. 5 is obtained by further adding 41 other inner conductors in the basic configuration shown in FIG. 1 to strengthen the electric field coupling between the resonator 1 and the resonator 2. This induces a current in the other resonator 2 in the direction in which the magnetic field coupling is canceled with respect to the wave incident on the resonator 1.

Example 6. FIG. 6 is a plan view showing the configuration of the high frequency filter according to the sixth embodiment. In the figure, the feature of this embodiment is that the inner structure of the second embodiment is further provided with 42 other inner conductors. The inner conductor 42 is provided on a surface different from the inner conductors 31a and 31b with respect to the dielectric substrate. Then, the electric field coupling between the resonator 1 and the resonator 2 is performed through the dielectric. In this embodiment, the input / output terminal 2
3g and 23h are also on different sides.

Example 7. FIG. 7 is a plan view showing the configuration of the high frequency filter according to the seventh embodiment. In the configuration of this embodiment, the inner conductor 41 in the fifth embodiment is on the same plane as the dielectric substrate, but in the present embodiment, 43 other inner conductors are dielectrically coupled to the inner conductors 21a and 21b. It is on the opposite side of the body.

Example 8. FIG. 8 is a diagram showing the configuration of the high frequency filter of the eighth embodiment. FIG. 8A shows a plan view thereof, and FIG. 8B shows a perspective view thereof. In this embodiment, another inner conductor provided to strengthen the coupling of 44 is provided on the surface of the dielectric substrate 26b opposite to the inner conductors 31a and 31b. That is, in FIG. 8B, the inner conductor 44 is drawn through the dielectric substrate 26b, and is composed of a U-shaped conductor wide portion 44a and a U-shaped conductor line portion 44b that form the bottom thereof. By providing the two U-shaped conductor line portions 44b, the current in the direction canceling the magnetic field coupling is further increased. That is, the signal incident on the resonator 1 induces a current in the resonator 2 in the direction of canceling the magnetic field coupling in the vicinity of the short-circuit end, and weakens the total coupling amount. This and the U-shaped wide portion 44a serve to strengthen electric field coupling.

Example 9. FIG. 9 is a plan view showing the configuration of the high frequency blocking filter of the ninth embodiment. In the figure, a resonator 1 having an upper inner conductor 31a and a lower inner conductor 32a and a resonator 2 having an upper inner conductor 31b and a lower inner conductor 32b are
The main line provided on the other surface of the dielectric body 26b of 51 is coupled through the dielectric body 26b at coupling portions of 52, respectively. The resonator 1 and the resonator 2 are quarter-wave resonators with one end short-circuited and one end open. Next, the operation of the high frequency blocking filter of this configuration will be described. Assuming that the resonator resonates at the frequency f ₀ in the above configuration, the signal applied to the main line 51 is absorbed by the resonator 1 side through the coupling portion 52 at the resonance frequency, and is almost output to the other end of the main line. Don't go. However, at frequencies other than f ₀ , the coupling to the resonator is weak, so that the incident wave on the main line remains almost unchanged.
Goes out from the output end of the other end of. As described above, the filter having the configuration of FIG. 9 has a function of a high frequency blocking filter. The resonance frequency is adjusted by the radial length of the resonator, etc., as in the high frequency filter of the previous embodiment. Also,
The strength of the bond can be easily changed by adjusting the number and length of the bond of the bond part 52. Thus
In addition to downsizing, there is an effect that the strength of the coupling degree of the coupling portion can be easily adjusted.

Example 10. FIG. 10 is a plan view showing the configuration of the high frequency filter of the tenth embodiment. In the figure, the main line 51 is the inner conductors 31a, 31b of the dielectric substrate 26b.
It is provided on the side opposite to. In addition, the main line 51
It has 53 joints on the same surface. Thus, the joint is
It may be provided on the resonator side or the line side. Since the operation of this embodiment is similar to that of the ninth embodiment, detailed description will be omitted.

Example 11. FIG. 11 is a cross-sectional view showing a cross section of the structure of the high frequency filter according to the eleventh embodiment. In the figure, as an example of the resonator, the inner conductor 31a is connected to the ring-shaped outer conductor 34 via the inner conductor 32a. Similarly, the inner conductor 31b of the other resonator is the inner conductor 3b.
It is connected to the outer conductor 34 via 2b. Outer conductor 3
4 has a short-circuit portion 24, and forms a ring-shaped outer conductor surface on the surface opposite to the dielectric 26b. Upper outer conductor 25
a is formed on one surface of the first layer dielectric 26a and
4b, and a ring-shaped installation surface is formed on the other surface of the dielectric 26a. Similarly, the lower outer conductor 25b is formed on one surface of the dielectric 26c and has the short-circuit surface 24.
A donut-shaped installation surface is formed on the other surface of c. These resonator, input / output terminal, upper outer conductor and lower outer conductor are
It has the same hollow surface and is stacked with 54 screws and 55 nuts in multiple layers. Reference numeral 56 is another reinforcing member. In this way, the high frequency filter and the outer conductor, which are manufactured with different configurations, can be easily formed in multiple layers to obtain a high frequency filter.

Example 12 FIG. 12 is a sectional view showing the structure of the high frequency filter of the twelfth embodiment. In the figure, a new part is that the size of the first-layer dielectric substrate 26a and the size of the second-layer dielectric substrate 26b have different lengths in the radial direction. This has the effect of facilitating the connection to the input / output terminal of the resonator 1. Further, in the band elimination filter, there is an effect that the degree of coupling of the coupling section 52 or the coupling 53 can be adjusted later.

Example 13. The resonance filter of the above-described embodiment has a characteristic that the resonance frequencies of the respective resonators are matched with each other, pass at the resonance frequency, and are blocked at other frequencies. Since the high frequency filter of the present invention has a high degree of electric field and magnetic field coupling between the resonators due to the above structure, it becomes a high frequency filter having a stop band in the vicinity of the pass band. FIG. 13 is a characteristic diagram showing the input / output frequency characteristics of the high frequency filter of this embodiment. FIG. 13A is a characteristic diagram when magnetic field coupling is strong, and FIG. 13B is a characteristic diagram when electric field coupling is strong. In FIG. 13C, a third resonator is provided and, for example, the electric field coupling between the first and second resonators is strengthened to generate a pole of f _r 1, and the second resonator is connected to the third resonator. Shows an example in which the magnetic field coupling is strengthened to generate the pole of f _r 2.

In the above embodiment, an example of a high frequency filter in which the band pass filter has a pole which is a stop band at the same time has been shown, but it goes without saying that a band pass filter and an independent band stop filter can be combined.

[0052]

As described above, according to the present invention, since the fan-shaped resonator is used, the filter can be miniaturized.

Further, since the T-shaped inner conductor is used as the resonator, there is an effect that the filter can be further downsized.

Further, since the electric field coupling surface is shaped so as to be coupled also in the circumferential direction, there is an effect that the degree of coupling can be easily adjusted.

Further, since the outer conductor is provided with the hollow portion, the grounding surface can be easily obtained and the processing is easy.

Furthermore, since another coupling body is used between the resonators, the coupling degree can be easily adjusted.

Furthermore, since another inner conductor is used between the resonators, the coupling degree can be easily adjusted.

Furthermore, since another inner conductor is used between the resonators, the coupling degree can be easily adjusted.

Further, since the main line and the resonator are coupled by providing the coupling portion, there is an effect that the band elimination filter can be downsized.

Furthermore, since a plurality of connecting portions are provided,
This has the effect of easily adjusting the degree of coupling.

Furthermore, since a plurality of connecting portions are provided,
This has the effect of easily adjusting the degree of coupling.

Further, since the outer conductor is provided with the hollow portion, the grounding surface can be easily obtained, and the working is facilitated.

Furthermore, there is the effect that the connection with the ground plane of the resonator is easy and the workability is high.

Furthermore, since the size of the dielectric in the radial direction is changed, the effect of facilitating the connection to the resonator and the main line and the adjustment of the coupling degree is obtained.

In the high frequency filter according to the present invention, since the T-shaped fan-shaped resonators are radially butted against each other, the resonators resonate at a frequency determined by the impedance of each resonator and pass therethrough, and a large degree of coupling can be obtained with a small shape. Therefore, there is an effect that a characteristic having a stop frequency determined by the coupling impedance in the vicinity of the pass frequency is obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a high frequency filter according to a first embodiment of the present invention.

FIG. 2 is a plan view showing the configuration of a high frequency filter according to a second embodiment of the present invention.

FIG. 3 is a plan view showing the configuration of a high frequency filter according to a third embodiment of the present invention.

FIG. 4 is a plan view showing the configuration of a high frequency filter according to a fourth embodiment of the present invention.

FIG. 5 is a plan view showing the configuration of a high frequency filter according to a fifth embodiment of the present invention.

FIG. 6 is a plan view showing the configuration of a high frequency filter according to a sixth embodiment of the present invention.

FIG. 7 is a plan view showing the structure of a high frequency filter according to a seventh embodiment of the present invention.

FIG. 8 is a diagram showing a configuration of a high frequency filter according to an eighth embodiment of the present invention.

FIG. 9 is a plan view showing the configuration of a high frequency blocking filter according to a ninth embodiment of the present invention.

FIG. 10 is a plan view showing the structure of a high frequency blocking filter according to a tenth embodiment of the present invention.

FIG. 11 is a sectional view showing a section of a high frequency filter according to an eleventh embodiment of the present invention.

FIG. 12 is a cross-sectional view showing a cross section of a high frequency filter according to a twelfth embodiment of the present invention.

FIG. 13 is a diagram showing an example of characteristics of Embodiment 13 of the present invention.

FIG. 14 is a diagram showing a configuration of a conventional stripline filter.

[Explanation of symbols]

20a Resonator 1, 20b Resonator 2, 21a, 21b
Inner conductor, 22 Outer conductor, 23a, 23b, 23c, 2
3d, 23e, 23f, 23g, 23h input / output terminals,
24 short circuit part, 25a upper outer conductor, 25b lower outer conductor, 26a, 26b, 26c dielectric, 30a resonator 1, 30b resonator 2, 31a, 31b, 31c, 31
d, 31e, 31f upper inner conductor, 32a, 32b lower inner conductor, 33a, 33b, 33c, 33d, 33e,
33f input / output terminal, 34 outer conductor, 41, 42, 4
3,44 Inner conductor, 51 Main line, 52,53 Coupling part.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideki Asao 5-1-1 Ofuna, Kamakura-shi Electronic Systems Research Center, Mitsubishi Electric Corporation

Claims (14)

[Claims] 1. At least first and second fan-shaped inner conductors are provided on the same dielectric, and a radially inner surface of the inner conductors is connected to an outer conductor which is connected to a ground conductor. Input / output terminals are directly or indirectly connected to the outer sides of the first and second inner conductors in the radial direction, and the first and second fan-shaped inner conductors are separated from each other by a predetermined angle on the same circumferential surface on the dielectric. A high-frequency filter installed radially from the outer conductor. 2. The first and second inner conductors are T-shaped inner conductors whose outer portions in the radial direction are circumferentially longer than the inner portion, and the T-shaped portions are long in the circumferential direction. The high-frequency filter according to claim 1, wherein the electric field coupling surfaces are formed by abutting each other at a required distance. 3. A T that is long in the circumferential direction of the first and second inner conductors.
3. The high-frequency filter according to claim 2, wherein the electric field coupling surfaces of the character-shaped portions that are in contact with each other have surfaces that also come into contact with each other in the circumferential direction of the inner conductor of the other party and are also in contact with the circumferential direction. 4. The outer conductor connecting the inner sides of the first and second inner conductors in the radial direction is further provided with a hollow central portion inside thereof. The described high frequency filter. 5. A surface which is on the same circumferential surface of the dielectric and is an intermediate surface for electric field coupling on the outer side in the radial direction of the first and second inner conductors and which is in contact with the first and second inner conductors. The high frequency filter according to claim 1, further comprising a U-shaped third inner conductor having a straight line on both sides and a bottom surface in the circumferential direction. 6. A third inner conductor is provided on a plane opposite to a plane on which the first and second inner conductors are placed on the dielectric, and the third inner conductor is at least the first and the second inner conductors. 2. The high frequency filter according to claim 1, wherein the high frequency filter has a portion which is projected on the plane and overlaps with the inner conductor on the outer side in the radial direction. 7. The third inner conductor has a U-shape having a band-shaped portion which is projected and overlaps with the coupling surfaces of the first and second inner conductors facing each other. Item 6. The high frequency filter according to item 6. 8. At least first and second fan-shaped inner conductors are provided on the same dielectric, and the inner surface of the inner conductor in the radial direction is connected to an outer conductor which is connected to a ground conductor. And a second fan-shaped inner conductor on the same circumferential surface of the dielectric body at a predetermined angle apart from each other, and the resonator is radially installed when viewed from the outer conductor, and the first and second resonators of the dielectric body are provided. A main line having input / output terminals is provided on a surface different from the inner conductor along outer circumferential edges of the first and second inner conductors, and the resonator and the main line are formed of the dielectric material. A high-frequency filter configured to sandwich and provide a desired degree of coupling on the circumferential surface of the resonator. 9. A plurality of projections are provided on outer circumferential edges of the first and second inner conductors of the resonator in order to obtain a desired degree of coupling between the resonator and the main line, 9. The high frequency filter according to claim 8, wherein the degree of coupling is changed depending on the number or length of the plurality of protrusions. 10. A plurality of protrusions are provided on a surface of the main line in contact with the outer sides of the first and second inner conductors in the circumferential direction so that the degree of coupling between the resonator and the main line has a desired value. 9. The high frequency filter according to claim 8, wherein the coupling degree is changed depending on the number or length of the plurality of protrusions. 11. The outer conductor connecting the inner sides of the first and second inner conductors in the radial direction is further provided with a hollow central portion inside thereof. The described high frequency filter. 12. A first dielectric member having a first and second inner conductors and an outer conductor having a hollow portion connecting the first and second inner conductors in the radial direction thereof, at least the hollow portion of the outer conductor is The second conductor has a doughnut-shaped second conductor surface on the side opposite to the inner conductor of the dielectric body, and a cylindrical conductor surface that connects the outer conductor and the second conductor to another second dielectric body. The high frequency filter according to any one of claims 4 to 7 or 8, wherein the ground conductor provided is in contact with the grounded portion at the hollow portion. 13. The high-frequency filter according to claim 12, wherein the first dielectric has a radial length different from the second radial length. 14. At least a first and a second on the same dielectric.
Each of which is provided with a T-shaped fan-shaped inner conductor whose outer portion in the radial direction is longer in the circumferential direction than the inner portion, and whose inner surface in the radial direction is connected to an outer conductor which is connected to the ground conductor. The conductors have a structure in which T-shaped upper portions which are long in the circumferential direction are talked with each other for a required distance and are brought into contact with each other to form an electric field coupling surface, and the inner side in the radial direction of the inner conductor is used as a magnetic field coupling surface. Input / output terminals are directly or indirectly connected to the outer side of the inner conductor in the radial direction, and the first and second fan-shaped inner conductors are separated from the same circumferential surface of the dielectric body by a predetermined angle and the outer conductor is formed. A high-frequency filter that is installed in a radial pattern when viewed from the perspective and has a pass frequency band determined by the impedance of each inner conductor and a stop frequency determined by electric field coupling and magnetic field coupling between the first and second inner conductors.