JPH098539A - Dielectric resonator antenna - Google Patents

Abstract

PURPOSE: To allow the dielectric resonator antenna configured small to send/ receive a circularly polarized wave. CONSTITUTION: A conductor plate 2 is adhered to a bottom side of a semispherical dielectric body 1 in which a change in a dielectric constant is a maximum and a minimum respectively in directions AB and CD orthogonal to each other, power is fed in phase through a 1st coaxial feeder and a 2nd coaxial feeder of the same length. Since the resonance frequency of the electric field differs in the directions AB, CD in the inside of the dielectric body 1, the electric field emitted from the antenna in the direction AB differs in phase from that in the direction CD by 90 deg. and the combined electric field of both the electric fields causes a circularly polarized wave.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circularly polarized dielectric resonator antenna for transmitting / receiving satellite broadcasting, satellite communication or mobile communication.

[0002]

2. Description of the Related Art In recent years, with the development of satellite broadcasting, satellite communication, mobile communication, etc., there have been cases in which devices for receiving these broadcasts and devices for transmitting and receiving communication are installed and mounted in general homes, automobiles, etc. It is increasing. Among these devices, the antenna is particularly installed outside the house or the moving body, so that the antenna needs to be particularly downsized due to the restrictions on the installation place, the appearance problem, and the like.

Conventionally, there is a resonant antenna using a dielectric as an example of miniaturizing such an antenna. A resonant antenna using a dielectric is an antenna in which the physical resonance length of the antenna is reduced by using a dielectric material having a relative permittivity larger than 1, and the size of the entire antenna is reduced. Examples of antennas include microstrip antennas and hemispherical dielectric resonator antennas.

The microstrip antenna is described, for example, in "Latest Planar Antenna Technology" supervised by Misao Haishi, published by General Technology Center Co., Ltd., and the hemispherical dielectric resonator antenna is described in, for example, iE transaction・ Antenna and Propagation 1
0 (1993) pp. 1390 to 1398 (IEEE
Trans. Antennas Propagation 10 (1993) P.1390-1398)
Has been announced.

In particular, the hemispherical type dielectric resonator antenna is produced by processing using a mold or the like and requires a small number of etching steps. Therefore, the hemispherical type dielectric resonator antenna is suitable for mass production of the antenna for consumer use, and has been conventionally used. The hemispherical dielectric resonator antenna uses linearly polarized waves.

[0006]

In the case of satellite broadcasting and satellite communication, circular polarization may be used for the purpose of effective frequency utilization by limiting the area by polarization, and in the case of mobile communication, linear polarization is used. When polarized waves are used, it is necessary to use circular polarized waves because cross-polarization components increase due to changes in the antenna angles of each other due to the positional relationship between the moving object and the base station, and reception sensitivity deteriorates. . In these cases, there is a problem that the conventional linearly polarized hemispherical dielectric resonator antenna cannot be used.

The present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a dielectric resonator antenna for transmitting and receiving satellite broadcasting, satellite communication, mobile communication, etc. using circularly polarized waves. It is what

[0008]

In order to achieve the above object, the present invention provides a sphere of a dielectric material having a maximum and minimum change in dielectric constant per unit length in a cross section passing through the center and orthogonal to each other, or , A dielectric spheroid having a constant dielectric constant, and a means for feeding the sphere of the dielectric.

In the present invention, instead of the dielectric sphere of the dielectric resonator antenna, a hemisphere in which the change in the dielectric constant per unit length is the maximum and the minimum in the cross sections which pass through the center of the bottom surface and are orthogonal to each other. A dielectric or a dielectric having a constant dielectric constant of a semi-spheroid having different major and minor axes of the bottom surface, and a conductor plate adhered to the bottom surface of the dielectric material.

The present invention also has, as power feeding means, one or a plurality of coaxial feed lines, the outer conductor of the coaxial feed line is connected to the conductor plate, and the inner conductor is the hemispherical dielectric. It is connected.

The present invention also provides, as a power feeding means, a rectangular shape on the conductor plate in a direction forming an angle of 45 degrees with the direction in which the change in the dielectric constant per unit length of the hemispherical dielectric is maximum. The power supply line is provided with slots having the same direction and arranged orthogonal to the slots and parallel to the conductor plate.

The present invention also provides, as a power feeding means, a cross shape in which the direction in which the change in the dielectric constant per unit length of the hemispherical dielectric is the maximum and the minimum is the same as the longitudinal direction of the slot on the conductive plate. The present invention is provided with two feed lines of equal length, each having a slot and arranged orthogonal to the cross-shaped slot and parallel to the conductor plate.

According to the present invention, as a power feeding means, the conductor plate has a slot whose rectangular longitudinal direction coincides with a direction forming an angle of 45 degrees with the major axis direction of the semi-spheroid, The power supply line is provided so as to be orthogonal to and parallel to the conductor plate.

The present invention also has, as power feeding means, a cross-shaped slot in which the major axis and minor axis directions of the semi-spheroid and the longitudinal direction of the slot coincide with each other in the conductor plate, and the cross-shaped slot is orthogonal to the cross-shaped slot. However, it is provided with two feed lines of equal length arranged in parallel with the conductor plate.

[0015]

Therefore, according to the present invention, since the change of the dielectric constant per unit length is the maximum and the minimum in the cross section passing through the center and orthogonal to each other in the spherical or hemispherical dielectric, the resonance wavelengths are orthogonal to each other. When the electric power is fed at the center frequency of the antenna by the feeding means such as the coaxial type feeding line or the slot, the electric fields generated by the dielectric resonator antenna and having mutually orthogonal directions can have a phase difference of 90 degrees. , Which has the effect of generating a circularly polarized wave, which is the sum of the electric fields of both.

Further, according to the present invention, the resonance wavelengths are different in the directions orthogonal to each other by the spheroid or semi-spheroidal dielectric material having a constant permittivity whose major axis and minor axis of the bottom surface are different from each other. When power is fed at the center frequency of the antenna, the mutually orthogonal electric fields generated by the dielectric resonator antenna can have a phase difference of 90 degrees, and circular polarization, which is the sum of the electric fields of the two, can be generated. Have an effect.

[0017]

【Example】

(Embodiment 1) Hereinafter, a first embodiment of the present invention will be described. FIG. 1 is a perspective view of a dielectric resonator antenna according to the first embodiment of the present invention.

In FIG. 1, reference numeral 1 is a dielectric material in which a hemisphere is filled with a dielectric material, 2 is a conductor plate adhered to the dielectric material, 3 is a first coaxial feed line, and 4 is a second. It is a coaxial feed line.

The operation of the dielectric resonator antenna configured as described above will be described below.

In FIG. 1, the hemispherical dielectric 1 is arranged so that the change in the dielectric constant per unit length is maximum and minimum in the AB direction and the CD direction, which are indicated by the alternate long and short dash lines in the figure. The conductor plate 2 is adhered to the flat bottom surface of the hemisphere.

The inner conductors of the first coaxial feed line 3 and the second coaxial feed line 4 are connected to the hemispherical dielectric 1,
The outer conductor is connected to the conductor 2, and the two coaxial feed lines are connected to an external device with the same length and used as input / output lines.

The inner conductor of the first coaxial feed line 3 is shown in FIG.
It is connected to the hemispherical dielectric 1 in a plane perpendicular to the bottom surface in the AB direction inside, and the position in the AB direction is determined by the impedance determined by the dielectric constant distribution. Similarly, the inner conductor of the second coaxial feed line 4 is connected to the hemispherical dielectric 1 in a plane perpendicular to the bottom surface in the CD direction in FIG. Since both coaxial feed lines have the same length, power is fed to the hemisphere in the same phase.

In the dielectric 1, an electric field in the AB direction is generated by the first coaxial power supply line 3 and an electric field in the CD direction is generated by the second coaxial power supply line 4, and the dielectric constant per unit length changes in each direction. , The physical length is equivalently changed, and the resonance frequencies have different values f1 and f2 in the respective directions.

In this case, the first coaxial feed line 3 and the second coaxial feed line 4 have an intermediate frequency f between f1 and f2.
When a signal of 0 is input, the electric field radiated from this dielectric resonator antenna is the same as the electric field in the AB direction having a different phase and C.
It becomes the sum of the electric fields in the D direction, and becomes circularly polarized when the phase difference between them is 90 degrees.

FIG. 2A shows A of the hemispherical dielectric 1 of FIG.
FIG. 2B shows an example of a change in the dielectric constant in the B direction, and FIG. 2B shows an example of a change in the dielectric constant in the CD direction.

In FIG. 2, 5 is a change in the dielectric constant in the AB direction, and 6 is a change in the dielectric constant in the CD direction. In this example, the change in the dielectric constant per unit length in the AB direction is the maximum, and the change in the dielectric constant per unit length in the CD direction is the minimum, so that the change in the dielectric constant 5 in the AB direction is 5, C
The distribution of the dielectric constant shown by the change 6 of the dielectric constant in the D direction can be obtained. In addition, the dielectric constant distribution in other directions including the center point O in FIG. 1 changes continuously with an intermediate value in the AB and CD directions.

In order to realize the change in the dielectric constant as shown in FIG. 2 with the hemispherical dielectric 1, materials having different dielectric constants are appropriately changed and mixed, or the same dielectric material is mixed with another dielectric material. It is possible to create relatively freely by changing the amount.

FIG. 3 shows an example of the relationship between the frequency and phase of the electric field in the AB direction and the electric field in the CD direction radiated from the dielectric resonator antenna. In FIG.
7 is the relationship between the frequency and the phase of the electric field in the AB direction, and 8 is the relationship between the frequency and the phase of the electric field in the CD direction. Since the change in the dielectric constant per unit length is the largest in the AB direction, the equivalent physical length is the minimum and the resonance frequency is the maximum value f1. C
Since the change in the dielectric constant per unit length is the minimum in the D direction, the equivalent physical length is the maximum and the resonance frequency is the minimum value f.
It becomes 2.

When a signal having an intermediate value f0 of both frequencies is input, the phase of the electric field in the AB direction radiated from the antenna is
From the relationship 7 between the frequency and the phase of the electric field in the AB direction, the frequency f0
C has a value of -45 degrees and radiates from the antenna
The phase of the electric field in the D direction has a value of 45 degrees at the frequency f0 according to the relationship 8 between the frequency and the phase of the electric field in the CD direction. Therefore, the phase difference between both electric fields is 90 degrees.

As described above, according to the present embodiment, the change in the dielectric constant per unit length is maximized and minimized in the cross sections that pass through the center of the bottom surface of the hemispherical dielectric and are orthogonal to each other, so that It is possible to generate mutually orthogonal electric fields having a phase difference, and it is possible to generate circularly polarized waves in the hemispherical dielectric resonator antenna.

In the above embodiment, two coaxial feed lines are used as the feeding means, but one coaxial feed line is used and the inner conductor of the coaxial feed line is AB at the center point O in FIG. You may make it connect with a hemispherical dielectric body in the direction where a 45 degree angle differs from a direction.

(Second Embodiment) A second embodiment of the present invention will be described below. FIG. 4 is a perspective view of a dielectric resonator antenna according to the second embodiment of the present invention.

In FIG. 4, 2 is a conductor plate, 3 is a first coaxial feed line, 4 is a second feed line, and 9 is a semi-spheroidal dielectric. 4 is different from the configuration of FIG. 1 in that a semi-spheroidal dielectric 9 having a constant dielectric constant is used instead of the hemispherical dielectric of FIG.

The operation of the dielectric resonator antenna configured as described above will be described below.

In FIG. 4, the semi-spheroid 9 is arranged on the conductor plate 2 so that the AB direction and the CD direction, which are indicated by alternate long and short dash lines in the figure, are the minor axis direction and the major axis direction of the ellipse of the bottom surface, respectively. It In the first coaxial feed line 3 and the second coaxial feed line 4, as in FIG. 1, the inner conductor and the dielectric are connected in a plane perpendicular to the bottom faces in the AB and CD directions, and the outer conductor is conductive. Connected to the body plate. Since both coaxial feed lines have the same length, power is fed to the hemisphere in the same phase. An electric field in the AB direction is generated in the dielectric 9 by the first coaxial feed line 3 and an electric field in the CD direction is generated by the second coaxial feed line 4, but the length of the dielectric 9 changes in each direction, and the resonance frequency is The values f1 and f2 are different in each direction.

In this case, the first coaxial feed line 3 and the second coaxial feed line 4 have an intermediate frequency f of f1 and f2.
When a signal of 0 is input, the electric field radiated from this dielectric resonator antenna is the same as the electric field in the AB direction having a different phase and C.
It becomes the sum of the electric fields in the D direction, and becomes circularly polarized when the phase difference between them is 90 degrees.

AB radiated from the dielectric resonator antenna
The relationship between the frequency and the phase of the electric field in the CD direction and the electric field in the CD direction is the same as that in the embodiment shown in FIG.

As described above, according to the present embodiment, it is possible to generate mutually orthogonal electric fields having a phase difference of 90 degrees in the major axis direction and the minor axis direction of the spheroidal dielectric 9, and the spheroidal structure Circularly polarized waves can be generated in the dielectric resonator antenna.

In the above embodiment, two coaxial feed lines are used as the feeding means, but one coaxial feed line is used and the inner conductor of the coaxial feed line is AB at the center point O in FIG. You may make it connect with a spheroidal dielectric in a direction different from the direction by 45 degrees.

(Embodiment 3) A third embodiment of the present invention will be described below. FIG. 5 is a perspective view of a dielectric resonator antenna according to the third embodiment of the present invention.

In FIG. 5, 1 is a hemispherical dielectric, 2 is a conductor plate, and the above is the same as the configuration of FIG. FIG.
1 is different from that of FIG. 1 in that
In place of the coaxial feed lines 3 and 4, a slot 10 which is a rectangular hole is provided in the conductor plate 2, and the conductor plate 2 is electrically connected to the conductor plate 2 at a distance from and in parallel with the hemispherical dielectric 1. The point is that the feed line 11 is arranged on the back surface side through the body plate 2 and at a right angle to the longitudinal direction of the slot 10.

The operation of the dielectric resonator antenna configured as described above will be described below.

In FIG. 5, the hemispherical dielectric 1 is arranged on the conductor plate 2 so that the change in the dielectric constant per unit length is maximum in the AB direction and minimum in the CD direction.

The slot 10 is a rectangular hole formed in the conductor plate 2, and is arranged so that the longitudinal direction of the slot 10 is different from the AB direction by 45 ° in the center O.

The feed line 11 is arranged in parallel with the conductor plate 2 with a space therebetween so as to intersect the hemispherical dielectric 1 on the back side and at a right angle to the longitudinal direction of the slot. The power supply line 11 is made of a conductor, and has a conductor plate 2 and a power supply line 1.
When a dielectric is inserted between the 1 and 2, it becomes a microstrip line.

An electric field in a direction perpendicular to the slot 10 is generated inside the hemispherical dielectric 1 by the slot 10. The electric field orthogonal to the slot 10 can be decomposed into electric field components in the AB direction and the CD direction, but since the resonance frequencies in the respective directions are different, this dielectric resonator antenna is similar to the embodiment of FIG. The radiated electric field from is phase-shifted by 90 degrees in the AB direction and the CD direction, and is circularly polarized.

As described above, according to the present embodiment, in the hemispherical dielectric resonator antenna that generates circularly polarized waves, the feeding means can be configured by a plane circuit, that is, a plane line.

Although the hemispherical dielectric 1 is used in the above embodiment, the semi-spheroidal dielectric 9 of the second embodiment is used instead of the hemispherical dielectric, and the ellipse of the bottom surface is in the minor axis direction. AB
The direction and the major axis direction may be arranged so as to coincide with the CD direction.

(Fourth Embodiment) The fourth embodiment of the present invention will be described below. FIG. 6 is a perspective view of a dielectric resonator antenna according to the fourth embodiment of the present invention.

In FIG. 6, 1 is a hemispherical dielectric, 2 is a conductor plate, and the above is the same as the configuration of FIG. Figure 6
1 is different from that of FIG. 1 in that
In place of the coaxial feed lines 3 and 4, the conductor plate 2 is provided with a cross-shaped slot 12 which is a cross-shaped hole, and the hemispherical dielectric 1 is parallel to the conductor plate 2 at a distance.
Means that the first and second feed lines 13 and 14 are arranged on the back surface side through the conductor plate 2 and so as to intersect the two longitudinal directions of the cross-shaped slot 12 at a right angle.

The operation of the dielectric resonator antenna configured as described above will be described below.

In FIG. 6, the hemispherical dielectric 1 is arranged on the conductor plate 2 so that the change in the dielectric constant per unit length is maximum in the AB direction and minimum in the CD direction.

The cross-shaped slots 12 are arranged so that the longitudinal directions of the slots coincide with the AB direction and the CD direction, respectively. Further, the first feeding line 13 and the second feeding line 14 are arranged in parallel with the conductor plate 2 with a space therebetween, on the side opposite to the hemispherical dielectric 1 and at a right angle to the longitudinal direction of the slot. To be done. The first feeding line 13 and the second feeding line 14 are made of a conductor, and when a dielectric is inserted between the conductor plate 2 and the first feeding line 13 and the second feeding line 14, , Becomes a microstrip line. Due to the cross-shaped slot 12, an electric field in the direction perpendicular to the slot is generated inside the hemispherical dielectric 1. That is, although electric fields in the AB direction and the CD direction are generated, since the resonance frequencies in the respective directions are different, the radiated electric field from this dielectric resonator antenna is the same as in the embodiment of FIG.
The phase is different by 90 degrees in the direction and becomes circular polarization.

FIG. 7 is a plan view of the first feeding line 13 and the second feeding line 14.

In FIG. 7, 2 is a conductor plate, 12 is a cross-shaped slot, 13 is a first feeding line, and 13 is a second feeding line. The first feeding line 13 and the second feeding line 14 are arranged so as to be orthogonal to the slot where the cross slot exists, but are connected to an external device by the feeding line having the same length.

As described above, according to the present embodiment, in the hemispherical dielectric resonator antenna that generates circularly polarized waves, the feeding means can be configured by a planar circuit.

Although the hemispherical dielectric 1 is used in the above embodiment, the semi-spheroidal dielectric 9 of the second embodiment is used in place of the hemispherical dielectric, and the ellipse of the bottom surface is in the minor axis direction. AB
The direction and the major axis direction may be arranged so as to coincide with the CD direction.

(Fifth Embodiment) The fifth embodiment of the present invention will be described below. FIG. 8 is a perspective view of a dielectric resonator antenna according to the fifth embodiment of the present invention.

In FIG. 8, reference numeral 15 is a dielectric sphere filled with a dielectric, 16 is a first balanced feed line provided inside the dielectric sphere 15, and 17 is a first balanced feed line 1.
6 is a second balanced feed line provided inside the dielectric sphere 15 as in 6.

The operation of the dielectric resonator antenna configured as described above will be described below.

The dielectric sphere 15 is represented by A indicated by a one-dot chain line in the figure.
It is configured so that the change in the dielectric constant per unit length is maximum and minimum in each of the B direction and the CD direction. The change in the dielectric constants in the AB and CD directions shown in FIG. 2 is an example. First balanced feed line 16 and second balanced feed line 17
Is usually a parallel two-wire line with a dipole antenna connected to the tip. The first balanced feed line 16 and the second balanced feed line 17 are installed on the planes in the AB direction and the CD direction, respectively.

Electric fields in the AB direction and the CD direction are generated inside the dielectric sphere 15 by the feed lines 16 and 17, but the resonance frequencies in the respective directions are different.
Similar to the embodiment described above, the radiated electric field from this dielectric resonator antenna has a 90 ° phase difference between the AB direction and the CD direction, and is circularly polarized.

As described above, according to this embodiment, the dielectric resonator antenna that generates circularly polarized waves can be formed of a spherical shape or a spheroid.

In the above embodiment, the spherical dielectric is used. However, instead of the spherical dielectric, a semi-spheroidal dielectric having a constant dielectric constant is used, with the minor axis direction being the AB direction and the major axis being the major axis. You may arrange | position so that a direction may correspond to CD direction.

[0065]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, a dielectric sphere, or a hemisphere and a conductor plate, in which the change of the dielectric constant per unit length is the maximum and the minimum in the cross section passing through the center and orthogonal to each other, Alternatively, a dielectric resonator antenna having a simple structure can be obtained by connecting a coaxial spheroid or a feeding means such as a slot to a spheroid or semi-spheroid of a dielectric having a constant permittivity and a conductor plate. , Circularly polarized waves can be generated.

[Brief description of drawings]

FIG. 1 is a perspective view of a dielectric resonator antenna according to a first embodiment of the present invention.

FIG. 2 is a characteristic diagram of a dielectric constant of the dielectric resonator antenna according to the first embodiment of the present invention.

FIG. 3 is a frequency-phase relationship diagram of the dielectric resonator antenna according to the first embodiment of the present invention.

FIG. 4 is a perspective view of a dielectric resonator antenna according to a second embodiment of the present invention.

FIG. 5 is a perspective view of a dielectric resonator antenna according to a third embodiment of the present invention.

FIG. 6 is a perspective view of a dielectric resonator antenna according to a fourth embodiment of the present invention.

FIG. 7 is a plan view of an essential part of a dielectric resonator antenna according to a fourth embodiment of the present invention.

FIG. 8 is a perspective view of a dielectric resonator antenna according to a fifth embodiment of the present invention.

[Explanation of symbols]

 1 Dielectric 2 Conductor Plate 3 First Coaxial Feed Line 4 Second Coaxial Feed Line 5 Change in Permittivity in AB Direction 6 Change in Permittivity in CD Direction 7 Relationship between Frequency and Phase of Electric Field in AB Direction 8 Relationship between Frequency and Phase of Electric Field in CD Direction 9 Semi-spheroidal Dielectric 10 Slot 11 Feed Line 12 Cross-shaped Slot 13 First Feed Line 14 Second Feed Line 15 Dielectric Sphere 16 First Balance Feed line 17 Second balanced feed line

Claims (9)

[Claims] 1. A dielectric sphere having a maximum and minimum change in permittivity per unit length in cross-sections passing through the center and orthogonal to each other, and a power feeding means to the sphere of the dielectric. Dielectric resonator antenna. 2. A dielectric resonator antenna according to claim 1, which has a spheroid of a dielectric material having a constant dielectric constant, instead of the dielectric sphere of the dielectric resonator antenna. 3. The dielectric sphere of the dielectric resonator antenna according to claim 1, in place of the dielectric sphere, a change in permittivity per unit length becomes maximum and minimum in a cross section that passes through the center of the bottom surface and is orthogonal to each other. A dielectric resonator antenna comprising a hemispherical dielectric and a conductor plate adhered to a bottom surface of the hemispherical dielectric. 4. A power supply means comprising one or a plurality of coaxial feed lines, wherein an outer conductor of the coaxial feed line is connected to the conductor plate and an inner conductor is connected to the hemispherical dielectric. 4. The dielectric resonator antenna according to claim 3. 5. As a power feeding means, the longitudinal direction of the rectangle coincides with the direction in which the change of the dielectric constant per unit length of the hemispherical dielectric is maximum and the direction forming an angle of 45 degrees with the conductor plate. 4. The dielectric resonator antenna according to claim 3, further comprising a feed line that has a slot that is parallel to the conductor plate and that is orthogonal to the slot. 6. As a power feeding means, the conductor plate has a cross-shaped slot in which the direction in which the change in the dielectric constant per unit length of the hemispherical dielectric becomes maximum and minimum and the longitudinal direction of the slot coincide with each other. 4. The dielectric resonator antenna according to claim 3, further comprising two feed lines having the same length and arranged orthogonal to the cross-shaped slot and parallel to the conductor plate. 7. A dielectric sphere of a dielectric resonator antenna according to claim 1, wherein a semi-spheroid with a constant permittivity and a semi-spheroid of which the major axis and the minor axis of the bottom surface are different, and the semi-spheroid. A dielectric resonator antenna having a conductor plate adhered to the bottom surface of the body. 8. As a power feeding means, the conductor plate has a slot whose rectangular longitudinal direction coincides with a direction forming an angle of 45 degrees with the major axis direction of the semi-spheroid, and is orthogonal to the slot. The dielectric resonator antenna according to claim 7, further comprising a feed line arranged in parallel with the conductor plate. 9. As a power feeding means, the conductor plate has a cross-shaped slot in which the major axis direction and the minor axis direction of the semi-spheroid coincide with the longitudinal direction of the slot, and the cross section is orthogonal to the cross-shaped slot. 8. The dielectric resonator antenna according to claim 7, further comprising two feed lines having the same length and arranged in parallel with the body plate.