JP2001085908A - Multimode resonator device, filter, composite filter device, duplexer and communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a resonator smaller even though the number of steps of the resonator is increased while adopting the structure of a semi-coaxial cavity resonator by respectively constructing resonators that resonate in a semi-TE mode with a plurality of pairs of conductor projections formed on the inner faces of a cavity as central conductors. SOLUTION: The respective open faces of an almost rectangular parallelepiped-shaped cavity main body 1 with the two faces opened are covered with cavity lids 2 and 3. The body 1 is molded and formed with aluminum or copper, and the lids 2 and 3 are made of a metal plate. Conductor projections 4a to 4d are provided at the center part of each of the inner faces of the body 1, screw holes are formed on the end faces of the open faces of the body 1, and the lids 2 and 3 are screwed down to form a cavity space surrounded by the body 1 and the lids 2 and 3. Both a coaxial cavity resonator formed by the projections 4a and 4b and a cavity inner space and a coaxial cavity resonator formed by the projections 4c and 4d and the cavity inner space resonate in a semi-TE mode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resonator device, a filter, a composite filter device, a duplexer, and a communication device using the same in which a plurality of resonance modes are multiplexed.

[0002]

2. Description of the Related Art Hitherto, a cavity resonator or a semi-coaxial resonator has been used as a resonator that handles relatively large power in a microwave band. The semi-coaxial resonator is also called a coaxial cavity resonator, and has a relatively high Q and is smaller than the cavity resonator. Therefore, the semi-coaxial resonator is effective for miniaturizing a filter or the like.

[0003]

However, in a mobile communication system of a cellular system such as a cellular phone, a filter provided in a base station is required to be further miniaturized with the development of micro cells. It has become to.

When a filter used in the base station or the like is configured using the semi-coaxial resonator, a necessary number of resonators are arranged, and the size of the entire filter increases. there were.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a resonator device, a filter, a composite filter device, a duplexer, and the like, which can be made compact even when the number of resonators is increased while adopting the structure of a semi-coaxial resonator. And a communication device using the same.

[0006]

According to the present invention, there is provided a multi-mode resonator device comprising a plurality of pairs of projecting conductor projections formed on a pair of inner surfaces of a cavity facing each other, and forming the pair of conductor projections. Resonators that resonate in the quasi-TEM mode are each configured as a center conductor.

In the multimode resonator device according to the present invention, a dielectric core is loaded near the tip of a pair of conductor protrusions.

[0008] The filter of the present invention is provided with means for coupling to the quasi-TEM mode of the multimode resonator device, and the input and output of signals are performed by the coupling means.

A composite filter device according to the present invention is provided by providing a plurality of the above filters.

A duplexer according to the present invention is provided with two sets of the above filters, wherein the input port of the first filter is a transmission signal input port, the output port of the second filter is a reception signal output port, and the first and second filters are provided. An input / output port shared by the two filters is an antenna port.

A communication device according to the present invention is configured using the above-described multi-mode resonator device, filter, composite filter device or duplexer.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of a multimode resonator device according to a first embodiment will be described with reference to FIGS. FIG. 1 is an exploded perspective view of the multimode resonator device. 1 in the figure
Is a substantially rectangular parallelepiped cavity body with two open sides,
Reference numerals 2 and 3 denote cavity lids that cover the respective opening surfaces of the cavity main body 1. The cavity body 1 is formed by casting aluminum or copper, or by cutting a metal material of these, and the cavity lids 2 and 3 are made of a metal plate. Conductive protrusions 4a, 4b, 4c, and 4d are provided at the center of each inner surface of the cavity body 1.
Screw holes are formed in the end surfaces of the two opening surfaces of the cavity main body 1, and the cavity lids 2 and 3 are screwed. With this structure, a space surrounded by the cavity body 1 and the cavity lids 2 and 3 is configured as a cavity space.

FIG. 1B is a front view of the cavity body 1 as viewed from one opening surface. The conductor protrusions 4a to 4d are joined or welded to the inner surface of the cavity body 1 using a joining agent such as solder. Or you may fix by screwing. Further, these conductor projections 4a to 4d may be formed integrally with the cavity body 1.

FIG. 2 shows an example of the electromagnetic field distribution of the two resonance modes of the multimode resonator device. In the figure, solid arrows indicate electric field vectors, and broken arrows indicate magnetic field vectors. (A) is a mode of a semi-coaxial resonator formed by the conductor protrusions 4a and 4b and the space in the cavity. The magnetic field vector draws a loop.

FIG. 2B shows the mode of the semi-coaxial resonator formed by the conductor protrusions 4c and 4d and the space in the cavity.
This is equivalent to the resonance mode shown in (A) rotated by 90 ° as a whole along the xy plane. Here, the direction in which the conductor protrusion extends is represented by a suffix, and the resonance mode shown in (A) is a quasi-TEM- _x mode, and the resonance mode shown in (B) is a quasi-T
Called EM- _y mode.

FIG. 3 is a diagram showing a structure for adjusting the resonance frequency of each of the two resonance modes and adjusting the coupling between the resonance modes of the multimode resonator device. FIG. 3 shows a front view as viewed from one opening surface of the cavity body 1. In FIG. 3, reference numerals 5a, 5b, 6a, and 6b denote adjusting screws extending in the axial direction (that is, directions parallel to the four planes) of the cavity main body 1 having a rectangular cylindrical shape. It is attached to a lid, and the amount of insertion into the cavity can be adjusted by screwing.

Of these adjusting screws, 5a and 5b are frequency adjusting screws. The amount of the frequency adjusting screw 5a protruding into the cavity determines the conductor protrusion 4
The resonance frequency of the quasi-TEM- _x mode is adjusted by changing the perturbation amount of the magnetic field component of the quasi-TEM- _x mode with axes a and 4b as axes. Similarly, the quasi-TE around the conductor protrusions 4c and 4d is determined by the amount of protrusion of the frequency adjusting screw 5b into the cavity.
The resonance frequency of the quasi-TEM- _y mode is adjusted by changing the perturbation amount of the magnetic field component of the M- _y mode.

Reference numerals 6a and 6b denote coupling adjusting screws, respectively, which give perturbations to the magnetic fields of the odd mode and the even mode, which are the modes in which the quasi-TEM- _x mode and the quasi-TEM- _y mode are coupled. The quasi-TEM- _x mode and the quasi-TEM- _y mode are coupled by causing a difference in the resonance frequencies of

FIG. 4 shows an example of the above-mentioned odd mode and even mode electromagnetic field distributions. The chain line in the figure indicates the axis of symmetry of the electric field distribution. The orientation shown in FIG.
Assuming that the orientation shown in (B) is the even mode, the insertion position of the coupling adjusting screw 6a shown in FIG. 3 is a place where the odd mode magnetic energy is large and the electric energy is small, and the even mode magnetic energy is small. , Where the electrical energy is large. The insertion position of the coupling adjustment screw 6b is
This is a position where the above relationship is completely reversed. Therefore,
By adjusting the amount of insertion of these two coupling adjusting screws 6a and 6b into the cavity, the resonance frequencies of the odd mode and the even mode are changed, and the quasi-TEM _-x mode and the quasi-TE mode are changed.
The M- _y mode is coupled with an arbitrary coupling coefficient.

FIG. 5 shows an example in which the above-described multimode resonator device is used as a filter including two-stage resonators.
In FIG. 5, reference numerals 11a and 11b denote coupling loops each formed by the inner wall surface of the cavity. That is, one end of each of the coupling loops 11a and 11b is joined to the inner wall surface of the cavity, and the other end is connected to the center conductor of the coaxial connector. The coupling loop 11a interlinks with the quasi-TEM- _x mode magnetic field whose axis is the direction in which the conductor protrusions 4a and 4b extend, and the quasi-TEM- _y mode magnetic field whose axis is the direction in which the conductor protrusions 4c and 4d extend. The loop surface is arranged so as not to interlink. One coupling loop 1
1b is a quasi-T whose axis is the direction in which the conductor protrusions 4c and 4d extend.
_Interlinks with the magnetic field of the EM- _y mode, and the conductor protrusions 4a and 4b
The loop surface is arranged in a direction that does not interlink with the quasi-TEM- _x mode magnetic field whose axis is the direction in which it extends.

With this structure, the coupling loop 11a has a quasi-T
Coupling with the EM- _x mode, the coupling loop 11b is quasi-TEM- _y
Combine with mode. The two TEM modes are coupled by providing the coupling adjusting screws 6a and 6b shown in FIG. This constitutes a filter having band-pass characteristics composed of two-stage resonators.

If the resonator is connected between a predetermined position of the transmission line and the ground, a trap filter or a band rejection filter can be formed.

FIG. 6 is a perspective view showing some other examples of the conductor projections used in the multimode resonator and the filter. In the example shown in FIGS. 1 to 5, the truncated quadrangular pyramid is used.
The shape may be a quadrangular prism as shown in FIG. 6A or a cylindrical shape as shown in FIG. Further, as shown in (B), a prismatic shape may be combined with a pyramid shape. Further, the shape may be a truncated cone as shown in FIG.

In the above-described example, it has been described that a predetermined conductor protrusion is formed in the cavity in advance. However, as shown in FIG. 7, a screw portion formed on a part of the conductor protrusion forms a screw on the inner wall surface of the cavity. In order to obtain a desired resonator characteristic, conductor protrusions having different lengths, widths, or shapes may be selectively mounted in the cavity. As a result, resonator devices having different characteristics can be formed using the same cavity.

FIG. 8 is a sectional view showing the configuration of the multimode resonator device according to the second embodiment. Here, the conductor protrusions 4a, 4b, 4c,
A dielectric core 7 is provided in a space where each end of 4d faces each other. The dielectric core 7 has a cubic shape, and is formed by baking on all four surfaces thereof, for example, Ag electrodes so as not to conduct, and the Ag electrodes are connected to the conductor protrusions 4a.
To 4d by soldering or the like.
In this way, by loading the dielectric core near the tip of the conductor protrusion facing each other, the capacitance generated in the gap between the conductor protrusions facing each other, that is, the tip capacitance of the semi-coaxial resonator can be increased, The resonance frequency can be reduced as compared with the case where no dielectric core is loaded.
Conversely, the cavity size for obtaining the same resonance frequency can be made smaller. In addition, according to such a structure, a dielectric core smaller than the cavity size is only loaded in a portion where the electric field is concentrated, so that compared to a structure in which the entire cavity is formed of a dielectric, Only a small amount of dielectric material is required, and the cost can be reduced.

FIG. 9 is a diagram showing a configuration of a multimode resonator device according to the third embodiment. In the example shown in FIG.
Dielectric core is supported by conductor protrusions,
In the example shown in FIG. 9, the dielectric core is attached to the inner surface of the cavity. (A) is a partial perspective view thereof, and (B) is a sectional view of a main part. In the figure, reference numeral 8 denotes a cylindrical support made of a low dielectric constant material, 9 denotes a screw, 10
Is a washer made of a low dielectric constant material. Dielectric core 7
A hole through which a screw 9 is inserted is formed in the dielectric core 7.
The dielectric core 7 is fixed at a predetermined height in the cavity by screwing in.

In this example, the four conductor projections 4a to 4a
A predetermined gap is formed between the end face of 4d and the dielectric core 7. According to this structure, by changing the size of the gap, it is possible to arbitrarily set the tip capacitance of the conductor projections facing each other over a wide range. Even if the coefficient of linear expansion of the dielectric core 7 and the coefficient of linear expansion of the conductor projections 4a to 4d and the cavity are significantly different, the dielectric core and the end face of the conductor projection are not joined, so that the joint surface has distortion. Does not occur.

FIG. 10 is a perspective view showing the configuration of a multimode resonator device according to the fourth embodiment. In this example, four conductor projections 4a to 4d are provided on the cavity body 1, and conductor projections 4e and 4f are provided on the cavity lids 2 and 3 so as to project inwardly of the cavity.

With this structure, a quasi-TEM- _z mode having the central axis in the direction in which the conductor projections 4e and 4f extend is generated, and a triple mode resonator device is obtained as a whole.

Next, FIG. 11 shows an example of the configuration of a duplexer. Here, the transmission filter and the reception filter are band-pass filters having the above configuration, and the transmission filter passes the frequency of the transmission signal and cuts off the frequency of the reception signal.
The reception filter, on the contrary, passes the frequency of the reception signal and blocks the frequency of the transmission signal. The connection position between the output port of the transmission filter and the input port of the reception filter is such that the electrical length from the connection point to the equivalent short-circuit surface of the resonator at the last stage of the transmission filter is 1 at the wavelength of the frequency of the reception signal. The relationship that the electric length from the connection point to the equivalent short-circuit plane of the first-stage resonator of the receiving filter is an odd multiple of 1/4 wavelength at the wavelength of the transmission signal. And As a result, the transmission signal and the reception signal are surely branched.

As described above, by providing a plurality of dielectric filters between ports commonly used and individual ports, a diplexer and a multiplexer can be similarly configured.

FIG. 12 shows the duplexer (duplexer).
FIG. 2 is a block diagram illustrating a configuration of a communication device using the communication device. As described above, the transmission circuit is connected to the input port of the transmission filter, the reception circuit is connected to the output port of the reception filter, and the antenna is connected to the input / output port of the duplexer.

In addition, the circuit elements such as the diplexer, the multiplexer, the combiner, and the distributor are constituted by the multi-mode resonator device, and the communication device is constituted by using these circuit elements. A communication device is obtained.

[0034]

According to the first aspect of the present invention, the quasi-TE
Since the M mode is used, a resonator having a high Q can be obtained, and furthermore, by multiplexing the resonator modes, the overall size can be reduced even when the resonator is multi-staged.

According to the second aspect of the present invention, the cavity size can be further reduced. In addition, since a dielectric core smaller than the cavity size is only loaded on the portion where the electric field is concentrated, it is possible to reduce the size and cost of the resonator using a small amount of dielectric material.

According to the third, fourth, and fifth aspects of the present invention,
A compact filter, a composite filter device and a duplexer having low insertion loss characteristics or high attenuation characteristics are obtained.

According to the sixth aspect of the present invention, a compact and Q
With the use of a resonator having a high value, a communication device with small size, low loss, and high gain can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a multimode resonator device according to a first embodiment.

FIG. 2 is a diagram showing an example of an electromagnetic field distribution of two resonance modes in the resonator device.

FIG. 3 is a diagram showing a configuration for frequency adjustment and coupling adjustment of the resonator device.

FIG. 4 is a diagram showing an example of an electromagnetic field distribution in a coupling mode of the resonator device.

FIG. 5 is a diagram showing an example of configuring a filter using the resonator device.

FIG. 6 is a perspective view showing some other configuration examples of the conductor projection.

FIG. 7 is a perspective view showing a configuration example of another conductor protrusion.

FIG. 8 is a cross-sectional view illustrating a configuration of a multimode resonator device according to a second embodiment.

FIG. 9 is a diagram showing a partial configuration of a multimode resonator device according to a third embodiment.

FIG. 10 is an exploded perspective view showing a configuration of a multimode resonator device according to a fourth embodiment.

FIG. 11 is a diagram showing a configuration of a duplexer according to a fifth embodiment.

FIG. 12 is a diagram showing a configuration of a communication device according to a sixth embodiment.

[Explanation of symbols]

 1-Cavity body 2,3-Cavity lid 4-Conductor projection 5-Frequency adjustment screw 6-Coupling adjustment screw 7-Dielectric core 8-Support base 9-Screw 10-Washer 11-Coupling loop

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5J006 HA04 HA15 JA01 JA05 JA09 JA15 KA06 KA11 LA01 LA21 MA05 MB02 NA02 NE03 PA01 PB01

Claims (6)

[Claims] 1. A quasi-TEM mode in which at least two pairs of a pair of convex conductor protrusions are formed on the inner surface of a cavity having a plurality of pairs of inner surfaces facing each other, and the pair of conductor protrusions is a central conductor. A multi-mode resonator device comprising resonators that resonate with each other. 2. The multi-mode resonator device according to claim 1, wherein a dielectric core is loaded near a tip of the pair of conductor protrusions. 3. A filter provided with means for coupling to the quasi-TEM mode of the multimode resonator device according to claim 1 or 2, wherein the coupling means performs signal input / output. 4. A composite filter device comprising a plurality of sets of the filters according to claim 3. 5. Two sets of filters according to claim 3 are provided,
A duplexer having an input port of the first filter as a transmission signal input port, an output port of the second filter as a reception signal output port, and an input / output port shared by the first and second filters as an antenna port. 6. A communication device comprising the multi-mode resonator device according to claim 1 or 2, a filter according to claim 3, a composite filter device according to claim 4, or a duplexer according to claim 5. .