JP3788055B2 - Dielectric resonator device, shared transmission and reception device, and communication device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dielectric resonator device including a multi-mode dielectric resonator, a transmission / reception shared device and a communication device using the dielectric resonator device.
[0002]
[Prior art]
A dielectric resonator that resonates by returning to its original position in the same phase while repeating total reflection at the boundary between the dielectric and air, is small and has a high unloaded Q (Qo) resonance. Used as a container. In this mode, a dielectric rod having a circular or rectangular cross section is cut to a length of s · λg / 2 (λg is the guide wavelength, s is an integer) of the TE mode or TM mode propagating through the dielectric rod. There are TE and TM modes that are sometimes obtained. When the cross-sectional mode is TM01 mode and s = 1, a TM01δ mode resonator is obtained, and when the cross-sectional mode is TE01 mode and s = 1, a TE01δ mode dielectric resonator is obtained.
[0003]
As shown in FIG. 17, these dielectric resonators have a circular waveguide or rectangular waveguide that cuts off the resonance frequency of the dielectric resonator as a cavity, and a cylindrical TM01δ mode dielectric core or A TE01δ mode dielectric core is disposed.
[0004]
FIG. 18 is a diagram showing the electromagnetic field distribution in the dielectric resonator of the above two modes. Here, a solid line indicates an electric field, and a broken line indicates a magnetic field.
[0005]
When a dielectric resonator device having a plurality of stages is constituted by dielectric resonators using such a dielectric core, a plurality of dielectric cores are arranged in the cavity. In the example shown in FIG. 17, the TM01δ mode dielectric cores of (A) are arranged in the axial direction, or the TE01δ mode dielectric cores of (B) are arranged along the same plane.
[0006]
In such a dielectric resonator device, when external coupling is employed, a probe such as a loop or an antenna is inserted into the resonator (resonance system) to be magnetically coupled or electric field coupled.
[0007]
However, in external coupling using a loop or antenna, a conductor (metal) is inserted into the resonance system, so that perturbation is added to the electromagnetic field distribution, resulting in unnecessary coupling between modes or fluctuation in the resonance frequency. Further, by inserting a loop or an antenna inside the resonator, the current path is perturbed and the no-load Q deteriorates. Also, since there are input / output coupling loops or antennas in one cavity, unnecessary coupling between loops or antennas is likely to occur.
[0008]
[Problems to be solved by the invention]
On the other hand, as a solution to the above-mentioned problem, a TEM mode or quasi-TEM mode resonator coupled to a dielectric resonator is provided and external coupling is performed by the resonator. No. 6, No. 6-6561, and No. 6-44201.
[0009]
However, in such a conventional dielectric resonator device, the size is increased by providing a TEM mode or quasi-TEM mode resonator for external coupling, and when a filter is configured, the number of resonator stages used increases. As a result, there is a problem that the entire apparatus is further increased in size.
[0010]
On the other hand, as one of the techniques for downsizing a device composed of a plurality of resonators, there is a method of using a multimode of a dielectric resonator. That is, it is possible to configure a resonator device in which a dielectric core that resonates in multiple modes is disposed in a cavity and a plurality of resonators are equivalently connected in cascade using a predetermined mode among these modes. However, when combining the TEM mode or quasi-TEM mode external coupling resonator with such a multi-mode dielectric resonator, the mode is changed to a predetermined mode among the modes of the multi-mode dielectric resonator. It is difficult in design to couple the resonator for external coupling only.
[0011]
An object of the present invention is to provide a dielectric resonator device that is small and includes a plurality of resonators, and to provide a dielectric resonator device that includes a resonator having a high unloaded Q.
[0012]
Another object of the present invention is to provide a transmission / reception shared device and a communication device using the dielectric resonator device.
[0013]
[Means for Solving the Problems]
According to a dielectric resonator of the present invention, as described in claim 1, a dielectric core that resonates in a plurality of modes in a cavity, and a slit that allows passage of electromagnetic fields of two or more modes among the plurality of modes. a conductor plate formed was a coupled resonator monomode in parallel coupled to all modes of the electromagnetic field passing through the slit, and an external coupling means for exciting said coupling resonator provided. With this structure, a dielectric resonator device in which a plurality of resonance mode resonators with a dielectric core are coupled in parallel to a coupling resonator is obtained.
[0014]
As the coupling resonator, a coaxial resonator is constituted by a linear or rod-shaped conductor and a cavity as described in claim 2. According to a third aspect of the present invention, a TM mode dielectric resonator is constituted by a columnar dielectric and a cavity as a coupling resonator.
[0015]
Since these coupling resonators are not selectively coupled to a single mode among a plurality of resonance modes of the dielectric core, but are coupled to a plurality of resonance modes, respectively, the design becomes easy.
[0016]
According to a fourth aspect of the present invention, the slit includes a plurality of slits that allow different modes of electromagnetic fields to pass therethrough, and the electromagnetic fields of all modes due to resonance between the dielectric core and the cavity by the plurality of slits. To pass. As a result, the coupling resonator is coupled to all the resonance modes of the dielectric core passing through the slit.
[0017]
According to a fifth aspect of the present invention, a transmission filter and a reception filter are configured by the dielectric resonator device, a transmission filter is provided between the input port and the input / output port, and the input / output port and the output are provided. A shared transmission / reception apparatus is configured by providing a reception filter between the ports. According to a sixth aspect of the present invention, the dielectric resonator device or the shared transmission / reception device is provided in the high-frequency circuit unit to constitute a communication device.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
The configuration of the dielectric filter according to the first embodiment of the present invention will be described with reference to FIGS.
[0019]
FIG. 1 is a perspective view of a dielectric resonator portion. In FIG. 1, reference numeral 1 denotes a substantially rectangular parallelepiped dielectric core, 2 denotes a rectangular tube-shaped cavity, and 3 denotes a support for supporting the dielectric core 1 at a substantially central portion of the cavity 2. A conductor film is formed on the outer peripheral surface of the cavity 2, and a dielectric plate or a metal plate on which the conductor film is formed is disposed on the two opening surfaces to form a substantially rectangular parallelepiped shield space. As will be described later, the opening surface of another cavity is opposed to the opening surface of the cavity 2 to couple the electromagnetic field of a predetermined resonance mode.
[0020]
The support 3 shown in FIG. 1 is usually made of a ceramic material having a dielectric constant lower than that of the dielectric core 1, and is disposed between the dielectric core 1 and the inner wall surface of the cavity 2 to be integrally fired.
[0021]
2 to 4 show resonance modes by the dielectric core 1 shown in FIG. In these drawings, x, y, and z are coordinate axes in the three-dimensional direction shown in FIG. 1, and FIGS. 2 to 4 show cross-sectional views on two-dimensional surfaces. 2 to 4, the solid line arrows indicate the electric field vector, the broken line arrows indicate the magnetic field vector, and the "·" symbol and the "x" symbol indicate the direction of the electric field or magnetic field. 2 to 4 show only a total of six resonance modes, ie, a TM01δ mode in three directions of x, y, and z and a TE01δ mode in the same three directions. In reality, these higher-order resonance modes also exist, but usually these fundamental modes are used.
[0022]
FIG. 5 is a perspective view showing the configuration of a dielectric filter using the six-mode dielectric resonator. The dielectric core 1 is the same as that shown in FIG. 1, and this dielectric core 1 is provided in the central portion of the cavity 2 to constitute a six-mode dielectric resonator. Reference numerals 6a and 6b denote conductors for the coaxial resonator, each end of which is connected (short-circuited) to the cavity 2 and the other end thereof is an open end. The coaxial resonator conductors 6a and 6b and the cavity 2 constitute a coaxial resonator having the coaxial resonator conductors 6a and 6b as inner conductors and the cavity 2 as an outer conductor. The coaxial resonator conductors 6a and 6b are arranged parallel to the yz plane and inclined at 45 degrees with respect to the xz plane as shown in the figure. Reference numerals 7a and 7b denote signal input / output coaxial connectors, and the respective center conductors are connected to predetermined positions of the coaxial resonator conductors 6a and 6b. As a result, the input signal from the coaxial connector excites the coaxial resonator and outputs the excitation signal of the coaxial resonator to the outside.
[0023]
Coupling plates 5a and 5b are provided between the dielectric core 1 and the coaxial resonator conductors 6a and 6b, respectively. As will be described later, the coupling plates 5a and 5b are formed with slits for adjusting the coupling amount between the coaxial resonator and each of the six-mode resonators of the dielectric core 1.
[0024]
FIG. 6 shows current distributions in six resonance modes on the coupling plates 5a and 5b. If this coupling plate is provided with a slit extending in a direction that obstructs the direction of current (in a direction orthogonal to the direction of current), the magnetic field in the resonance mode leaks from the slit and both resonators sandwiching the coupling plate are magnetically coupled. It will be.
[0025]
FIG. 7 shows an example of slits formed in the coupling plate. As is clear from comparison with the current distribution shown in FIG. 6, the slit S1 is formed in a direction that blocks the current of the other five modes except the TM01δ- _x mode (turns the current path around). In addition, the slit S2 is formed in a direction that blocks current in five modes other than the TE01δ- _x mode. Accordingly, the two slits S1 and S2 leak the magnetic fields of all six modes. On the other hand, as shown in FIG. 7B, the coaxial resonator conductors 6a and 6b are inclined at 45 degrees with respect to the xz plane so as to be perpendicular to the slits. It couple | bonds with the magnetic field which leaks from slit S1, S2. Eventually, the coaxial resonator will be magnetically coupled to all six modes of the dielectric resonator. If a coaxial resonator is used as the coupling resonator in this manner, new spurious due to the provision of the coupling resonator hardly occurs.
[0026]
FIG. 8 is an equivalent circuit diagram of the dielectric filter. In the figure, the quasi-TEM mode resonator is the coaxial resonator. In this way, a dielectric filter is configured in which coaxial resonators are coupled in parallel with each of the six-mode resonators of the dielectric core. The resonance frequency of each mode is determined by forming a frequency adjusting hole or groove at a predetermined location of the dielectric core. The amount of coupling between the coaxial resonator and each resonance mode is determined by the size, position, orientation, or shape of the slit formed in the coupling plate.
[0027]
In FIG. 5, the central conductors of the coaxial connectors 7a and 7b do not enter the resonance system of the multi-mode dielectric resonator by the dielectric core 1, so that the electromagnetic field distribution is not perturbed and unnecessary between modes. Neither coupling nor resonance frequency fluctuates. In addition, no unnecessary coupling occurs between the input and output coupling loops.
[0028]
In the above example, the central conductor of the coaxial connector is directly connected to the coaxial resonator conductor, but a coupling loop that magnetically couples to the coaxial resonator may be provided.
[0029]
Next, the configuration of the dielectric filter according to the second embodiment will be described with reference to FIGS.
In the first embodiment, each of the six resonance modes is used as an independent resonator in one stage. However, in the second embodiment, coupling between several resonance modes is also used.
[0030]
FIG. 9 shows the electromagnetic field distribution of each mode when the first-stage resonator is TM01δ- _y , the second-stage resonator is TE01δ- _z , and the third-stage resonator is TM01δ- _x . (B) is a diagram showing a coupling relationship between two resonance modes to be coupled. The diagram shown on the left side of (B) shows the electric field distribution of the first-stage TM01δ- _y mode and the second-stage TE01δ- _z mode superimposed. Here, energy is transferred from the TM01δ- _y mode to the TE01δ- _z mode by breaking the balance of the electric field strength at the points a and b. Accordingly, as shown on the left side of (C) in the figure, for example, by expanding the inner diameter of the coupling adjustment hole Ha to make a difference in size from the coupling adjustment hole Hb, the TM01δ- _y mode of the first stage is changed. The strength of coupling between the resonator and the second-stage TE01δ- _z mode resonator is determined.
[0031]
Similarly, the diagram shown on the right side of (B) shows the electric field distribution of the second-stage TE01δ- _z mode and the third-stage TM01δ- _x mode superimposed. Here, the energy is transferred from the TE01δ- _z mode to the TM01δ- _x mode by breaking the balance of the electric field strength at the points c and d. Therefore, as shown on the right side of (C) in the figure, for example, by expanding the inner diameter of the coupling adjustment hole Hc to give a difference in size from the coupling adjustment hole Hd, the second stage TE01δ- _z mode The strength of coupling between the resonator and the third-stage TM01δ- _x mode resonator is determined.
[0032]
FIG. 10 shows the electromagnetic field distribution in each mode when the first-stage resonator is TE01δ- _x , the second-stage resonator is TM01δ- _z , and the third-stage resonator is TE01δ- _y . (B) is a diagram showing a coupling relationship between two resonance modes to be coupled. The diagram shown on the left side of (B) shows the electric field distribution of the first-stage TE01δ- _x mode and the second-stage TM01δ- _z mode superimposed. Here, energy is transferred from the TE01δ- _x mode to the TM01δ- _z mode by breaking the balance of the electric field strength at the points e and f. Therefore, as shown on the left side of (C) in the figure, for example, by expanding the inner diameter of the coupling adjusting hole He to make a difference from the size of the coupling adjusting hole Hf, the first TE01δ- _x mode The strength of coupling between the resonator and the second-stage TM01δ- _z mode resonator is determined.
[0033]
Similarly, the diagram shown on the right side of (B) shows the electric field distribution of the second-stage TM01δ- _z mode and the third-stage TE01δ- _y mode superimposed. Here, the energy is transferred from the TM01δ- _z mode to the TE01δ- _y mode by breaking the balance of the electric field strength at the points g and h. Therefore, as shown on the right side of FIG. 8C, for example, by expanding the inner diameter of the coupling adjustment hole Hg to make a difference in size from the coupling adjustment hole Hh, the second stage TM01δ- _z mode The coupling strength between the resonator and the TE01δ- _y mode resonator at the third stage is determined.
[0034]
FIG. 11 is a perspective view showing a configuration of a dielectric filter using the above six modes in total. Unlike the case of the first embodiment, here, dielectric pillars indicated by 8a and 8b are provided inside the cavity 2 to form a TM101 mode resonator and a TM011 mode resonator, and these are used as coupling resonators. Yes. Further, coaxial connectors 7a and 7b are provided in the cavity 2, and their central conductors are connected to the coupling loops 4a and 4b. The coupling loop 4a is magnetically coupled to the resonator formed by the dielectric column 8a, and the coupling loop 4d is magnetically coupled to the resonator formed by the dielectric column 8b.
[0035]
In FIG. 11, the TM101 mode by the dielectric pillar 8a is magnetically coupled to the TM01δ- _y mode and the TE01δ- _x mode by the dielectric core 1, respectively. The TM011 mode by the dielectric pillar 8b is magnetically coupled to the TM01δ- _x mode and the TE01δ- _y mode by the dielectric core 1, respectively.
[0036]
The coupling plates 5a and 5b are provided with slits Sa and Sb in the direction in which the magnetic field of the resonance mode by the dielectric columns 8a and 8b passes. These coupling resonators using the dielectric pillars 8a and 8b are not selectively coupled to the only one of the plurality of resonance modes of the dielectric core, but are coupled to two resonance modes in this example. Therefore, the design becomes easier. For example, a design with a high degree of difficulty is not required in which the coupling resonator is coupled to only one of the TM01δ- _x mode and the TE01δ- _y mode.
[0037]
FIG. 12 is an equivalent circuit diagram of the dielectric filter. In this way, a circuit is configured in which a resonator circuit in which three stages of resonators are cascade-connected is coupled in parallel to a TM mode coupling resonator.
[0038]
In FIG. 11, the coupling loops 4a and 4d provided in the coaxial connectors 7a and 7b do not enter the resonance system of the multimode dielectric resonator by the dielectric core 1, so that the electromagnetic field distribution is not perturbed. No unnecessary coupling between modes occurs and the resonance frequency does not fluctuate. In addition, no unnecessary coupling occurs between the input and output coupling loops.
Further, when a TM single mode dielectric resonator is used as the coupling resonator in this way, there is almost no decrease in the no-load Q due to the coupling resonator.
[0039]
FIG. 13 is a perspective view showing a configuration of a dielectric filter according to the third embodiment. Unlike the example shown in FIG. 11, a part of the coupling plates 5a and 5b is cut out and coupling loops 4b and 4c are provided. The coupling loop 4b is magnetically coupled to the TM101 mode by the dielectric pillar 8a and magnetically coupled to the TM01δ- _y mode by the dielectric core 1. The coupling loop 4c is magnetically coupled to the TM011 mode by the dielectric pillar 8b and magnetically coupled to the TM01δ- _x mode by the dielectric core 1. Other configurations are the same as those in the second embodiment. Therefore, the entire equivalent circuit is as shown in FIG. Thus the bond between the TM101 modes and the TM01deruta _-y mode by providing the coupling loop 4b strong position of the magnetic field strength of TM01deruta _-y modes becomes stronger. Similarly, by providing the coupling loop 4c strong position of the magnetic field strength of TM01deruta _-x mode coupling between TM011 mode and TM01deruta _-x mode increases.
[0040]
In this way, two sets of resonator circuits coupled in parallel are brought into a predetermined balance state to obtain a predetermined filter characteristic. Since the coupling loops 4b and 4c are only used supplementarily, there is little decrease in the no-load Q due to this.
[0041]
Next, FIG. 15 shows a configuration example of the shared transmission / reception apparatus. Here, the transmission filter and the reception filter are dielectric filters having the configurations shown in the above embodiments. The transmission filter passes the frequency of the transmission signal and blocks the frequency of the reception signal, and the reception filter 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 final stage of the transmission filter is 1 at the wavelength of the frequency of the reception signal. / 4 Wavelength is an odd multiple, and the electrical length from the connection point to the equivalent short-circuit plane of the first-stage resonator of the reception filter is an odd multiple of a quarter wavelength at the frequency of the transmission signal frequency. It is said. This reliably branches the transmission signal and the reception signal.
[0042]
Thus, by providing a plurality of dielectric filters between the commonly used ports and the individual ports, a diplexer and a multiplexer can be configured in the same manner.
[0043]
FIG. 16 is a block diagram showing a configuration of a communication apparatus using the duplexer. 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, thereby configuring the high-frequency unit of the communication device.
[0044]
In addition, a compact and highly efficient communication device can be obtained by configuring the diplexer, the multiplexer, and the like with a multimode dielectric resonator and configuring a communication device using these circuit elements.
[0045]
【The invention's effect】
According to the first to fourth aspects of the present invention, since a probe such as a loop or an antenna for external coupling is not inserted into the resonance system of the dielectric resonator that resonates in a plurality of modes, perturbation to the electromagnetic field distribution is reduced. Thus, unnecessary coupling between modes and unnecessary coupling between input and output probes are less likely to occur, and a decrease in no-load Q due to the probes is also reduced. In addition, since the coupling resonator is not selectively coupled to a single mode among the plurality of resonance modes of the dielectric core, but is coupled to each of the plurality of resonance modes, the design becomes easy.
[0046]
According to the fourth aspect of the present invention, the coupling resonator can be selectively and easily coupled to a predetermined mode among a plurality of resonance modes by the dielectric core.
[0047]
Moreover, according to the invention which concerns on Claim 5, it has a filter characteristic with high Q, and can comprise a small transmission / reception sharing apparatus.
[0048]
Moreover, according to the invention which concerns on Claim 6, a small and highly efficient communication apparatus is obtained.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a configuration of a multimode dielectric resonator used in a dielectric filter according to a first embodiment. FIG. 2 is a cross-sectional view showing an electromagnetic field distribution in each mode of the dielectric resonator. 3 is a cross-sectional view showing the electromagnetic field distribution in each mode of the dielectric resonator. FIG. 4 is a cross-sectional view showing the electromagnetic field distribution in each mode of the dielectric resonator. FIG. 5 is an overall configuration of the dielectric filter. FIG. 6 is a diagram showing current distribution in each mode on the coupling plate in the dielectric filter. FIG. 7 is a diagram showing an example of forming slits in the coupling plate. FIG. 8 is an equivalent circuit of the dielectric filter. FIG. 9 is a diagram showing an electromagnetic field distribution of each mode to be sequentially coupled and a configuration of a coupling adjustment hole of a multimode dielectric resonator used in the dielectric filter according to the second embodiment. Many used for the dielectric filter according to the embodiment FIG. 11 is a perspective view showing an overall configuration of a dielectric filter according to a second embodiment. FIG. 11 is a diagram showing a configuration of an electromagnetic field distribution and a coupling adjusting hole of each mode sequentially coupled in a mode dielectric resonator. Equivalent circuit diagram of the dielectric filter FIG. 13 is a perspective view showing the entire configuration of the dielectric filter according to the third embodiment. FIG. 14 is an equivalent circuit diagram of the dielectric filter. FIG. 16 is a diagram showing a configuration of a communication device. FIG. 17 is a partially broken perspective view showing a configuration of a conventional dielectric resonator device. FIG. 18 is a diagram illustrating a conventional single-mode dielectric resonator. Figure showing an example of electromagnetic field distribution 【Explanation of symbols】
1-dielectric core 2-cavity 3-support 4-coupling loop 5-coupling plate 6-coaxial resonator conductor 7-coaxial connector 8-dielectric pillar H-coupling adjustment hole S-slit

Claims (6)

A dielectric core that resonates in a plurality of modes in a cavity, a conductor plate in which a slit that allows passage of electromagnetic fields of two or more of the plurality of modes is formed, and all modes of the electromagnetic field that have passed through the slits A dielectric resonator device comprising: a single-mode coupling resonator coupled in parallel to each other; and external coupling means for exciting the coupling resonator. The coupling resonator, dielectric resonator apparatus of claim 1 which is coaxial resonator constituted by said linear or rod-shaped conductor cavity. 2. The dielectric resonator device according to claim 1, wherein the coupling resonator is a TM-mode dielectric resonator including a columnar dielectric and the cavity. The slit comprises a plurality of slits that allow different modes of electromagnetic fields to pass therethrough, and the plurality of slits allow all modes of electromagnetic fields due to resonance between the dielectric core and the cavity to pass therethrough . 4. The dielectric resonator device according to 2 or 3.   A transmission filter and a reception filter are configured by the dielectric resonator device according to any one of claims 1 to 4, wherein the transmission filter is provided between an input port and an input / output port, and the input / output port and the output port are provided. A transmission / reception shared device in which the reception filter is provided between them.   5. A communication device comprising the dielectric resonator device according to claim 1 or the transmission / reception shared device in a high frequency circuit section.

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