JPH0856106A - High frequency resonator and high frequency filter - Google Patents

Abstract

PURPOSE:To obtain a high frequency resonator and a high frequency filter whose size is further smaller than the size of a conventional strip line resonator. CONSTITUTION:An open-end of a single line 12 making up of a strip line or a microstrip line and whose one-end connects to a ground conductor 13 for grounding is branched into plural lines. Thus, the small sized high frequency resonator with an excellent harmonic suppression characteristic is formed by changing a characteristic impedance of open-ends 122-123 and a ground part 121 stepwise at the branched part and the plural branched lines are folded respectively to make the resonator small. Furthermore, the small sized high frequency filter is realized by arranging the resonators above side by side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency resonator and a filter used in a high frequency region such as a microwave band.

[0002]

2. Description of the Related Art In recent years, small-sized and low-cost portable terminals have been actively developed in mobile communication. To this end, downsizing of the radio circuit is essential, and downsizing of the resonator, which occupies a particularly large volume in this radio,
There is a strong demand for higher performance. A quarter-wave resonator is widely used as a resonator having a strip or microstrip line structure for a resonator in a high frequency band. However, the resonator has a size larger than that of other components, and thus constitutes a resonator. Attempts have been made to realize miniaturization by changing the characteristic impedance of the line in steps.

A conventional high frequency resonator having an impedance step will be described below. Here, a microstrip line resonator will be described as an example.

FIG. 12 is a perspective view showing a microstrip line resonator in which the characteristic impedance is changed stepwise.

In FIG. 12, 1 is a dielectric substrate, 2 is a microstrip line which serves as a resonance element, 3 is a ground conductor,
4 is a ground conductor 3 formed on the front and back surfaces of the dielectric substrate 1.
Is a via hole that connects

In the above structure, the line width of the microstrip line 2 is changed stepwise to change the characteristic impedance of the line stepwise.
In this example, by making the thickness of the open portion of the microstrip line 2 thicker than that of the ground portion, the impedance Z ₁ of the ground portion is made higher than the impedance Z _{2 of the} open portion, and the resonator is miniaturized. With the above configuration, the resonant element operates as a quarter-wave resonator with one end open and the other end grounded.

[0007]

However, while miniaturization is achieved by integrating the radio section circuit of the mobile terminal,
A device using a resonator has a problem that its shape is still larger than that of other parts even if the above-mentioned conventional resonator is used.

The present invention solves the above-mentioned conventional problems, and achieves both miniaturization of a resonator and reduction of loss, and has a structure having harmonic suppression characteristics, in which the conventional impedance is changed stepwise. It is an object of the present invention to provide a high-frequency resonator having a size smaller than that of the resonator and a small-sized high-frequency filter using the resonator.

[0009]

In order to achieve the above object, according to the present invention, an open end side of a single line composed of a strip or microstrip line with one end grounded is branched into a plurality of lines and bent. As a result, the characteristic impedance is changed stepwise between the open end side and the ground end side to form a small high-frequency resonator.

Further, according to the present invention, the ground end side of a single line whose one end is composed of a strip or a microstrip line is opened, and the ground end side is branched into a plurality of lines and bent, so that the open end side and the ground end side have characteristics. The impedance is changed stepwise to form a small-sized high-frequency resonator with low loss.

The present invention further comprises a high-frequency resonator having the above-mentioned structure and an input / output coupling circuit connected to an external circuit, and the high-frequency resonators are arranged side by side so that an open end, a ground end or a branch portion of the high-frequency resonator are adjacent to each other. This constitutes a small-sized high-frequency filter.

[0012]

With the above structure, the characteristic impedance on the open end side of the line serving as the resonance element is made lower than that on the ground end side, so that the resonator is smaller than the quarter wavelength resonator having a uniform impedance. In addition, it is possible to realize a smaller resonator than the conventional resonator in which the impedance is changed stepwise by branching the open end side into multiple lines and bending them. Yes, a small filter can be realized by combining these.

Further, according to the present invention, the characteristic impedance of the ground end side of the single line is made lower than that of the open end side so that the resonator can have a lower loss than the resonator having a uniform impedance. Since the ground end side is branched into a plurality of lines and they are bent, it is possible to realize a small-sized resonator with low loss, and by combining these, a low-loss filter can be realized.

[0014]

【Example】

(Embodiment 1) Hereinafter, a first embodiment of the present invention will be described with reference to FIG.
Will be described with reference to. 1 is a perspective view of a high frequency resonator according to a first embodiment of the present invention. In FIG.
Reference numeral 11 is a dielectric substrate, 12 is a microstrip line resonator, 121 is a ground end of the microstrip line resonator 12, 122 and 123 are open ends of the microstrip line resonator 12, and 13 is a ground conductor. , 14 are ground conductors 13 formed on the front and back surfaces of the dielectric substrate 11.
Is a via hole that connects

The operation of the high-frequency resonator configured as above will be described below. In the high frequency resonator of this embodiment shown in FIG. 1, the characteristic impedances of the open end portion and the ground end portion are changed at the branch portion of the line of the microstrip line resonator 12.

The relationship between the conventional resonator shown in FIG. 12 and the resonator of this embodiment will be described with reference to FIG.

FIG. 2A shows a resonator 22 having a conventional impedance step. In this example, the open end 220
Since the line width of the part is thicker than the line width of the ground end 221, the impedance of the open end 220 part is lower than that of the ground end 221 part. Under these conditions, the resonator length is shortened, and is made smaller than the quarter-wave resonator having a uniform characteristic impedance.

FIG. 2 (b) shows an equivalent circuit of FIG. 2 (a). The impedance on the open end 220 side in FIG. 2A is equivalent to a parallel connection of a line having a higher impedance, that is, a line having a narrow line width. FIG. 2B shows an example in which two lines having open ends 222 and 223 are connected in parallel.

FIG. 2 (c) is a diagram showing the resonator of this embodiment, in which the circuit of FIG. 2 (b) has open ends 222 and 223.
Since each of the two lines is bent 180 degrees toward the grounding end 221, the characteristic length of the line changes stepwise, and the resonator length is shortened from a quarter wavelength. In addition, the resonator having a small height is realized by bending the line at the open end toward the grounded end.

As shown in FIG. 1, the reason why the line is cut diagonally at the bent portion of the line at the open end is to prevent impedance discontinuity other than at the branch portion.

Since the characteristic impedance of the high-frequency resonator shown in FIG. 1 is changed stepwise, the odd-order higher-order resonance frequency, which is a problem in the quarter-wavelength resonator, is an odd multiple of the fundamental resonance frequency. Since they can be displaced from each other, this high-frequency resonator can have a suppressing effect on harmonics.

When the resonance frequency deviates from the desired frequency, the frequency can be easily adjusted by cutting the open ends 122 to 123 and changing the resonance line length.

As described above, according to this embodiment, the open ends 122 and 123 of the resonator are branched into a plurality of lines and bent, so that the characteristic impedance of the resonant element becomes stepwise. It is possible to realize a high-frequency resonator that is changed and is compact and has excellent harmonic suppression characteristics.

In this embodiment, an example in which the open end portion of the resonator is branched into two lines has been shown, but it goes without saying that it may be branched into three or more lines. Also, it is possible to realize even if the thickness and length of the branched lines are not equal, and even if each of the branched lines is bent in an arbitrary direction due to the space for arranging the resonators, a resonance having the same characteristics is obtained. It goes without saying that vessels can be realized.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a perspective view of a high frequency resonator according to a second embodiment of the present invention.

3 is different from that of FIG. 1 in that
The point is that not the open ends 122 and 123 side of the microstrip line resonator 12 in FIG. 1 but the ground ends 322 and 323 side are branched into a plurality of lines.

In FIG. 3, 31 is a dielectric substrate, 32 is a microstrip line resonator, 321 is an open end of the resonator 32, 322 and 323 are ground ends of the resonator 32, 33 is a ground conductor, and 34 is a dielectric. It is a via hole that connects the ground conductor 33 formed on the front surface and the back surface of the substrate 31.

The operation of the high-frequency resonator configured as above will be described below. The high frequency resonator of this embodiment shown in FIG. 3 has an open end 321 portion and a ground end 322, 3
The characteristic impedance of the portion 23 is changed at the branch portion of the line of the microstrip line resonator 32. However, by branching the ground ends 322, 323 side into a plurality of lines, the characteristic impedance of the ground ends 322, 323 side is changed. Since the height is lower than that on the open end 321 side, the ground end 32 where the current is maximum in the microstrip line resonator 32 is obtained.
The conductor loss in the portions 2, 323 is reduced, and a resonator with a high unloaded Q is realized. Normally, if the impedance on the open end 321 side is made higher than that on the ground ends 322, 323 side, the resonator length becomes longer than that of the quarter-wavelength resonator having uniform impedance, but the ground ends 322, 323 are A small shape is formed by branching into a plurality of lines and bending 180 degrees. Similar to the first embodiment, the reason why the line is obliquely cut at the bent portion is to prevent impedance discontinuity other than at the branch portion.

Since the high-frequency resonator shown in FIG. 3 changes the characteristic impedance in steps, the odd-order higher-order resonance frequency, which is a problem in the quarter-wavelength resonator, is an odd multiple of the fundamental resonance frequency. Since they can be displaced from each other, this high-frequency resonator can have a suppressing effect on harmonics. When the resonance frequency deviates from the desired frequency, the open end 321 is cut and the resonance line length is changed.
The frequency can be adjusted easily.

As described above, according to the present embodiment, the grounding ends 322 and 323 of the microstrip line resonator 32 are branched into a plurality of lines and bent, so that the characteristic impedance of the resonance element is reduced. It is possible to realize a small-sized high-frequency resonator that is locally changed and has low loss and excellent harmonic suppression characteristics.

In this embodiment, the grounding ends 322 and 323 of the microstrip line resonator 32 are divided into two lines, but it may be divided into three or more lines. Needless to say. Further, it is possible to realize even if the branched lines are not equal in thickness and length, and even if the branched lines are bent in arbitrary directions depending on the arrangement space of the resonator and the position of the ground conductor. It goes without saying that a resonator having similar characteristics can be realized.

(Embodiment 3) A third embodiment of the present invention will be described below with reference to FIG. FIG. 4 is a plan view of the high frequency resonator according to the third embodiment of the present invention as seen from above. In FIG. 4, 42 is a microstrip line resonator, 43 is a ground conductor, and 45 is a ground capacitance that connects the open end of the resonator 42 and the ground conductor 43.

The operation of the high frequency resonator configured as described above will be described below. FIG. 4A shows the high frequency resonator shown in the first embodiment in which a ground capacitance 45 is connected between two open ends and a ground conductor. Also, FIG.
(B) is one in which a grounding capacitance 45 is connected between the open end of the high-frequency resonator shown in the second embodiment and the grounding conductor. The basic operation is the same as in the first and second embodiments. By adding the ground capacitance 45, the length of the microstrip line resonator 42 can be further shortened, and the larger the capacitance value, the smaller the resonator becomes.

As described above, according to this embodiment, by adding the grounding capacitance 45 between the open end of the microstrip line resonator 42 and the grounding conductor 43, it is possible to realize a more compact high frequency resonator. is there.

(Embodiment 4) A fourth embodiment of the present invention will be described below with reference to FIG. FIG. 5 is a plan view of the high-frequency resonator according to the fourth embodiment of the present invention as seen from above. In FIG. 5, 52 is a microstrip line resonator, 53 is a ground conductor, and 56 is a distributed coupling circuit provided between the open end of the resonator 52 and the ground conductor 53.

The operation of the high-frequency resonator configured as above will be described below. FIG. 5A shows a distributed coupling of the open end of the high frequency resonator shown in the first embodiment and the ground conductor 53. Further, FIG. 5 (b) shows a distributed coupling of the open end of the high-frequency resonator shown in the second embodiment and the ground conductor. Basic operation is 1st and 2nd
Is the same as the embodiment described above. By providing the distributed coupling circuit 56, the length of the resonator 72 is further shortened, and the higher the coupling degree of the distributed coupling circuit 56, the smaller the high frequency resonator.

As described above, according to the present embodiment, by adding the distributed coupling circuit 56 between the open end of the microstrip line resonator 52 and the ground conductor 53, a more compact high frequency resonator can be realized. Is.

(Fifth Embodiment) A fifth embodiment of the present invention will be described below with reference to FIG. FIG. 6 is a plan view and a cross-sectional view of a high frequency resonator according to a fifth embodiment of the present invention as seen from above. In FIG. 6, 61 is a dielectric substrate,
62 is a microstrip line resonator, 63 is a ground conductor, 621 is the ground end of the resonator 62, 622 and 623 are open ends of the resonator 62, and 624 is the ground end 621 of the resonator 62.
Via holes for connecting the ground conductor 63 to the ground conductors 671, 67
2 is an overlay metal and 681 to 682 are overlay dielectrics.

The operation of the high-frequency resonator configured as above will be described below. In FIG. 6A, the open ends 622 and 623 of the high-frequency resonator shown in the first embodiment are brought close to the ground conductor 63 to be distributedly coupled.

FIG. 6B shows the open ends 622 and 623 of the microstrip line resonator 62 which are distributedly coupled to the ground conductor 63 through the dielectric 61 in the vertical direction.

Incidentally, FIG. 6 (c) shows A in FIG. 6 (b).
It is sectional drawing cut | disconnected by the -A 'line. As shown in this figure, the ground conductor 63 is configured such that the vertical gap between the ground conductor 63 and the dielectric of the dielectric substrate 61 is narrowed by the open end portion of the microstrip line resonator 62. The characteristic impedance of the open end portion of the resonator 62 is further lowered, and the entire size can be reduced.

FIG. 6D shows an open end 622 of the resonator 62,
623 and the ground conductor 63 with overlay dielectrics 681, 68
Overlay metal 671 and 672 provided on the upper side through 2
Is distributed and combined by.

Incidentally, FIG. 6 (e) shows B in FIG. 6 (d).
It is sectional drawing cut | disconnected by the -B 'line. Basic operation is first
Is the same as the embodiment described above. Thus, as shown in FIGS.
The length of the resonator 62 can be further shortened by the distributed coupling shown in (3), and the resonator is downsized as the degree of coupling of the distributed coupling is increased. The resonance frequency can be adjusted as shown in FIG.
This can be easily performed by trimming the open ends 622 and 623 in the case of (b) and the overlay metal 671 and 672 in the case of FIG. 6 (d).

As described above, according to this embodiment, a gap or an overlay is used for the open end of the resonator and the ground conductor.
Alternatively, it is possible to realize a small-sized high-frequency resonator in which frequency adjustment is easy by performing distributed coupling by a structure in which the dielectric layers are vertically stacked.

(Embodiment 6) A sixth embodiment of the present invention will be described below with reference to FIG. FIG. 7 is a perspective view of a high frequency filter according to a sixth embodiment of the present invention.

In FIG. 7, 71 is a dielectric substrate, 72 is a microstrip line resonator, 73 is a ground conductor, and 74 is a ground conductor.
Is a ground conductor 7 formed on the front and back surfaces of the dielectric substrate 71.
Via holes connecting the three, 721 to 726 are resonators 7
Open ends 2 and 791 and 792 are input / output coupling circuits composed of capacitors.

The operation of the high frequency filter configured as described above will be described below. In FIG. 7, three high frequency resonators shown in the first embodiment are arranged side by side so that the lines at the open ends are adjacent to each other. In FIG. 7, open ends 722 and 723 and 724 and 725 are adjacent to each other. Since this high-frequency resonator has a small size as described in the first embodiment, a filter constructed by using this resonator can be realized in a very small size. Input / output coupling circuit 7
91 and 792 are composed of capacitors connected to the lines at the open ends 721 and 726. The center frequency of this high frequency filter is adjusted by opening the ends 722 and 72 of the resonator 72.
This can be easily done by trimming 3, 724 and 725.

As described above, according to this embodiment, the microstrip line resonators 72 shown in the first embodiment are arranged side by side so that the lines of the open ends 722 and 723 and 724 and 725 are adjacent to each other. By doing so, a very small high-frequency filter can be realized.

In this embodiment, an example of a three-stage high frequency filter in which three microstrip line resonators 72 are arranged is shown, but it goes without saying that a high frequency filter can be realized regardless of the number of resonators. Further, in the present embodiment, an example in which a capacitor is connected to the open ends 721 and 726 as an input / output coupling circuit has been shown. A coupling circuit can be configured, and a high frequency filter having similar characteristics can be realized.

(Embodiment 7) A seventh embodiment of the present invention will be described below with reference to FIG. FIG. 8 is a perspective view of a high frequency filter according to a seventh embodiment of the present invention.

In FIG. 8, 81 is a dielectric substrate, 82 is a microstrip line resonator, 83 is a ground conductor, and 84.
Is a ground conductor 8 formed on the front and back surfaces of the dielectric substrate 81.
Via holes for connecting 3 and resonators 81-2826
The two ground terminals, 891 and 892, are input / output coupling circuits composed of taps.

The operation of the high frequency filter configured as described above will be described below. FIG. 8 shows an arrangement in which three high frequency resonators shown in the second embodiment are arranged side by side so that the lines at the ground end portions are adjacent to each other. In FIG. 8, the ground ends 822 and 823 and 824 and 825 are adjacent to each other. Since this high-frequency resonator has a high unloaded Q as described in the second embodiment, it is possible to realize a small and low-loss filter. The input / output coupling circuits 891 and 892 are connected to the ground terminal 8
It is composed of taps connected to the lines 21 and 826. The center frequency of this high frequency filter is adjusted by trimming the open end of the central portion of the resonator 82, and the input / output coupling is adjusted by the input / output coupling circuit 891.
This can be easily done by trimming the tap portion at the tip of 892.

As described above, according to this embodiment, by arranging the resonators shown in the second embodiment side by side so that the lines of the ground end portion are adjacent to each other, a small high-frequency filter with low loss can be realized. It is possible.

In this embodiment, an example of a three-stage high frequency filter in which three resonators are arranged is shown, but it goes without saying that a high frequency filter can be realized regardless of the number of resonators. Further, in this embodiment, the input / output coupling circuit 79
Although an example in which a tap is provided at the ground end portion is shown as 1,792, an input / output coupling circuit can be configured even when magnetically coupled to the ground end by an inductor or a parallel coupling line, and a high frequency filter having similar characteristics is realized. It is possible.

(Embodiment 8) An eighth embodiment of the present invention will be described below with reference to FIG. FIG. 9 is a plan view of the high frequency filter according to the eighth embodiment of the present invention as seen from above. In FIG. 9, 921 and 922 are microstrip line resonators, and 991 and 994 are input / output coupling circuits configured by parallel coupling lines.

The operation of the high frequency filter constructed as described above will be described below. FIG. 9A shows the high-frequency resonator shown in the first embodiment arranged so that the branch portions of the lines are adjacent to each other. FIG. 9B shows the high-frequency resonator shown in the second embodiment, which is arranged so that the branch portions of the lines are adjacent to each other.

With the configuration shown in FIG. 9, a two-stage filter having a very small size in FIG. 9A and a low loss in FIG. 9B can be realized. The input / output coupling circuits 991 and 992 are resonators 921.
The input / output coupling circuits 993 and 994 are magnetically coupled to the line at the open end of the resonator, and the input / output coupling circuits 993 and 994 are magnetically coupled to the line at the ground end of the resonator 922. The center frequency of the high-frequency filter can be easily adjusted by trimming the open ends of the resonators 921 and 922, and the input / output coupling can be easily adjusted by trimming the tips of the input / output coupling circuits 991 and 992.

As described above, according to the present embodiment, by arranging the branch portions of the resonator lines so as to be adjacent to each other, it is possible to realize a high-frequency filter having a very small size and low loss.

In this embodiment, the input / output coupling circuit 99 is used.
Although an example in which 1 and 992 and 993 and 994 are parallel coupled lines is shown, an input / output coupling circuit is configured by a capacitance or a gap for an open end portion and an inductor or a tap for a ground end portion. However, a high frequency filter having the same characteristics can be realized.

(Ninth Embodiment) A ninth embodiment of the present invention will be described below with reference to FIG. FIG. 10 is a plan view of the high frequency filter according to the ninth embodiment of the present invention as seen from above. In FIG. 10, 1021 to 1023 are microstrip line resonators, and 1091 and 1092 are input / output coupling circuits composed of gaps.

The operation of the high frequency filter configured as described above will be described below. FIG. 10 shows the lines of the open end portions of the high frequency resonators 1021 and 1023 shown in the first embodiment and the high frequency resonator 10 shown in the second embodiment.
The lines at the grounding end portions of 22 are alternately arranged so as to be adjacent to each other. Resonator 10 whose open end is branched
21 and 1023 and a resonator 1022 branched from the ground end portion
Have different spurious responses, a high-frequency filter configured by alternately combining these has a wider stop band and a higher spurious suppression effect than a combination of the same resonators.

Further, since the degree of coupling between the open end portion and the ground end portion is relatively small, interstage coupling becomes sparse and narrow band characteristics can be obtained even if the resonators are arranged close to each other. It is possible to realize a small narrow band filter, which is usually large. The input / output coupling circuits 1091 and 1092 are configured by providing a gap between the line at the open end and the tip of the input / output line. The center frequency of the high frequency filter can be easily adjusted by trimming the open ends of the resonators 1021 to 1023, and the input / output coupling can be easily adjusted by trimming the gap width.

As described above, according to the present embodiment, the resonator having the open end portion branched and the resonator having the ground end portion branched are arranged so that the line at the open end portion and the line at the ground end portion are adjacent to each other. A small high-frequency filter having a high spurious suppression effect can be realized by alternately arranging the two.

In the present embodiment, the example in which the input / output coupling circuit is connected to the resonator whose open end is branched is shown. However, even if the grounded end is connected to the resonator branched, a good spurious response is obtained. It goes without saying that a small-sized high-frequency filter that it has can be realized. Further, in the present embodiment, an example in which three resonators are arranged is shown, but it goes without saying that a high frequency filter can be configured regardless of the number of resonators.

(Embodiment 10) The tenth embodiment of the present invention will be described below with reference to FIG. FIG. 11 is a plan view of a high frequency filter according to the tenth embodiment of the present invention as seen from above. In FIG. 11, 1121, 11
22 is a microstrip line resonator, 1191, 12
An input / output coupling circuit 92 is connected to an external circuit.

The operation of the high frequency filter configured as described above will be described below. In FIG. 11, the high-frequency resonator 1121 shown in the first embodiment and the high-frequency resonator 1122 shown in the second embodiment are arranged side by side so that the branched portions are adjacent to each other. Resonators 1121 and 1122
Have different spurious responses, the high-frequency filter configured by combining them has a wider stopband and a higher spurious suppression effect than a combination of the same resonators. The input / output coupling circuit 1191 is configured by gap coupling with the line at the open end portion of the resonator 1121, and the input / output coupling circuit 1192 is configured by tap coupling with the line at the ground end portion of the resonator 1122. By using both electric field coupling and magnetic field coupling for output coupling, it is possible to improve both the attenuation characteristics of the stop band on the low band side and the stop band on the high band side of the pass band. The center frequency of this high frequency filter is adjusted by the microstrip line resonator 1
This can be easily done by trimming the open ends of 121 and 1122. Further, the input / output coupling can be easily adjusted by trimming the taps and the gaps.

As described above, according to the present embodiment, by arranging the resonator having the open end portion branched and the resonator having the ground end portion branched so that the branched portions are adjacent to each other, spurious suppression is achieved. It is possible to realize a compact high-frequency filter having a high effect, and also to realize a high-frequency filter having good attenuation characteristics by utilizing both electric field coupling and magnetic field coupling in the input / output coupling circuit.

In this embodiment, two input / output coupling circuits are provided on opposite sides of the resonator, but it goes without saying that a high frequency filter can be realized even if they are provided on the same side.

[0069]

As described above, according to the present invention, the open end portion of the resonator is branched and bent, so that the conventional line impedance is partially changed and the resonator is miniaturized. It is possible to realize a compact high-frequency resonator. In addition, by forming a structure in which the grounded end portion of the resonator is branched and bent, it is possible to realize a small high-frequency resonator with low loss. Since the high-frequency resonator of the present invention has a non-uniform line impedance, it has an effect of suppressing harmonics, and has a characteristic useful as a high-frequency device such that the resonance frequency can be easily adjusted by trimming the open end. ing.

Further, the high frequency resonator of the present invention can be further miniaturized by adding a capacitance and a distributed coupling circuit to its open end. In this case, the resonance frequency can be easily adjusted by trimming and overlaying the coupling line.

Further, by arranging the high-frequency resonators of the present invention side by side so that the open end portion, the ground end portion, and the branch portion are adjacent to each other, it is possible to construct a more compact high-frequency filter than before. In this case, a filter with excellent harmonic suppression characteristics can be realized by arranging different types of high-frequency resonators alternately, and attenuation characteristics can be achieved by using both electric field coupling and magnetic field coupling in the input / output coupling circuit. A good filter can be realized.

As described above, according to the present invention, it is possible to realize a high frequency resonator and a high frequency filter which are compact and have excellent features.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a high frequency resonator according to a first embodiment of the present invention.

FIG. 2 is a plan view showing the relationship between a conventional high frequency resonator and the high frequency resonator according to the first embodiment of the present invention.

FIG. 3 is a perspective view showing a configuration of a high frequency resonator according to a second embodiment of the present invention.

FIG. 4 is a plan view showing the structure of a high frequency resonator according to a third embodiment of the present invention.

FIG. 5 is a plan view showing the structure of a high frequency resonator according to a fourth embodiment of the present invention.

FIG. 6 is a plan view and a sectional view showing the structure of a high-frequency resonator according to a fifth embodiment of the present invention.

FIG. 7 is a perspective view showing the configuration of a high frequency filter according to a sixth embodiment of the present invention.

FIG. 8 is a perspective view showing the configuration of a high frequency filter according to a seventh embodiment of the present invention.

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

FIG. 10 is a plan view showing the configuration of a high frequency filter according to a ninth embodiment of the present invention.

FIG. 11 is a plan view showing the configuration of a high frequency filter according to a tenth embodiment of the present invention.

FIG. 12 is a perspective view showing a configuration of a conventional high frequency resonator.

[Explanation of symbols]

1, 11, 31, 61, 71, 81 Dielectric substrate 2, 12, 22, 32, 42, 52, 62, 72, 8
2, 921, 922, 1021, 1023, 1121,
1122 Microstrip line resonator 3, 13, 33, 43, 53, 63, 73, 83 Ground conductor 4, 14, 34, 74, 84 Via hole

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H01P 5/08 H

Claims (21)

[Claims] 1. A grounding end in which one end of a single line composed of a strip or a microstrip line is grounded, and a tip of the single line not on the side of the grounding end is branched into a plurality of lines and bent to open. High-frequency resonator having an open end described above. 2. A single line composed of a strip or a microstrip line, and a grounding end having one end of the single line branched into a plurality of lines and bent to be grounded.
A high-frequency resonator having an open end in which the end of the single line that is not on the ground end side is open. 3. The high frequency resonator according to claim 1, wherein a ground capacitance is added to the open end. 4. The high frequency resonator according to claim 3, wherein the ground capacitance is replaced with a distributed coupling circuit with a ground conductor. 5. The high frequency resonator according to claim 4, wherein the distributed coupling circuit with the ground conductor is formed by arranging the side surfaces of the line close to each other on the same plane. 6. The high frequency resonator according to claim 4, wherein the distributed coupling circuit with the ground conductor is formed by bringing the ends of the lines close to each other on the same plane. 7. The high-frequency resonator according to claim 4, wherein the distributed coupling circuit with the ground conductor is composed of a coupling line which is vertically formed via a dielectric. 8. The high frequency resonator according to claim 4, wherein the distributed coupling circuit with the ground conductor is formed by providing an overlay on the upper portion. 9. At least two high-frequency resonators according to claim 1, and an input / output coupling circuit for connecting the high-frequency resonator and an external circuit, and branching at the open end side of the high-frequency resonator. The high-frequency filter is characterized in that each line of the open end portion is branched so as to be adjacent to the ground end side of the high-frequency resonator so that the respective lines of the ground end portion are adjacent to each other. 10. At least two high-frequency resonators according to claim 1 and an input / output coupling circuit for connecting the high-frequency resonator and an external circuit are provided, and branch portions of lines of the high-frequency resonator are adjacent to each other. A high-frequency filter characterized by being arranged like this. 11. A first high-frequency resonator configured by branching the ground end side of the high-frequency resonator according to claim 1 and a open-end side of the high-frequency resonator according to claim 1. A second high-frequency resonator configured as above, and an input / output coupling circuit that connects the first and second high-frequency resonators to an external circuit,
The line at the ground end of the first high-frequency resonator and the second line
2. A high-frequency filter characterized in that the lines at the open ends of the high-frequency resonator are alternately arranged so as to be adjacent to each other. 12. The high-frequency resonator according to claim 1, wherein the first high-frequency resonator is formed by branching the open end side and the second high-frequency resonator is formed by branching the ground end side. And an input / output coupling circuit for connecting the first and second high-frequency resonators to an external circuit, and arranging so that branch portions of the lines of the first and second high-frequency resonators are adjacent to each other. High frequency filter characterized by. 13. The high frequency filter according to claim 9, wherein the input / output coupling circuit is a capacitor connected to the line of the open end portion of the high frequency resonator. 14. The high frequency filter according to claim 9, wherein the input / output coupling circuit is an inductor connected to a line of a ground end portion of the high frequency resonator. 15. The high-frequency filter according to claim 9, wherein the input / output coupling circuit is a distributed constant circuit that is electric-field coupled with the line at the open end of the high-frequency resonator. 16. The high frequency filter according to claim 9, wherein the input / output coupling circuit is a distributed constant circuit that magnetically couples with the line at the ground end of the high frequency resonator. 17. The input / output coupling circuit uses one of an input side and an output side as a distributed constant circuit for electric field coupling with a line at an open end portion or a capacitor connected to a line at an open end portion, and the other as a line at a ground end portion. 13. The high frequency filter according to claim 9, wherein the high frequency filter is a distributed constant circuit magnetically coupled to the inductor or an inductor connected to a line at a ground end. 18. A distributed constant circuit electrically coupled to an open end is provided by providing an input / output line connected to an external circuit and providing a gap between the tip of the input / output line and the line at the open end. Claim 1 characterized in that
The high frequency filter according to claim 5 or claim 17. 19. A distributed constant circuit that is electric-field-coupled to an open end is configured by providing an input / output line connected to an external circuit, and connecting the line at the open end and the input / output line in parallel. The high frequency filter according to claim 15 or claim 17. 20. A distributed constant circuit magnetically coupled to a ground end is configured by providing an input / output line connected to an external circuit, and connecting the input / output line to the line at the ground end using the tip of the input / output line as a tap. 17. The method according to claim 16, wherein
Alternatively, the high frequency filter according to item 17. 21. A distributed constant circuit magnetically coupled to a ground end is provided with an input / output line connected to an external circuit, and the input / output line is grounded in the vicinity of the grounded end. The high frequency filter according to claim 16 or 17, which is characterized in that.