JP2003273613A - Dielectric resonator and dielectric characteristic measuring instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dielectric resonator having a high quality factor and further, to provide a dielectric characteristic measuring instrument in which dielectric characteristics of a dielectric sample can be obtained with high precision. <P>SOLUTION: A plate-like dielectric member 3 is held between two divided void resonators 2. A coaxial cable 5 is disposed in each void resonator 2, and a loop 6 is provided on its top. The loop 6 is formed to make the area of a region surrounded with the loop smaller than or equal to 0.001 multiple of the area of a face vertical to a Z-axis direction in the void part of the void resonator 2 or to make a ratio of a lateral inner diameter and a longitudinal inner diameter (lateral inner diameter/longitudinal inner diameter) equal to or larger than '1'. Besides, the dielectric sample of unknown dielectric characteristics is located in place of the dielectric member 3 and a degeneracy cancel member formed by combining three rectangular PTFE sheets into recess is provided. Thus, the dielectric characteristic measuring instrument capable of obtaining the dielectric characteristics of the dielectric sample with high precision can be provided. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter used in a high frequency band of GHz band or higher, a dielectric resonator used for an oscillator, etc., and a dielectric for measuring dielectric properties (dielectric constant and dielectric loss tangent) of a dielectric. The present invention relates to a characteristic measuring device.

[0002]

2. Description of the Related Art A dielectric resonator is small and
As a resonator that can obtain a high Q value (reciprocal of loss), it is used in various resonance circuits, filters, oscillators, and the like. However, at present, since it is desired to further improve the frequency characteristics of the resonance circuit and the filter, it is necessary to further improve the Q value of the dielectric resonator. Therefore, in order to obtain a dielectric resonator having a higher Q value, the structure of the dielectric resonator is reviewed and developed.

Further, in order to obtain a compact dielectric resonator having a high Q value, a microwave dielectric ceramic material having a high relative permittivity and a high Q value is required. Dielectric ceramic materials are also being developed. In order to develop such a microwave dielectric ceramic material, an evaluation method that can evaluate the relative dielectric constant and dielectric loss tangent of the microwave dielectric ceramic material with high accuracy and high efficiency is required. Various studies have also been conducted on the evaluation method. Among them, currently,
Using the TE ₀₁₁ mode and TE ₀₁₂ mode of the dielectric resonator, the relative permittivity ε _r of the microwave dielectric ceramic material,
The method for measuring the dielectric loss tangent tan δ is well known (reference: Kobayashi, Sato; “Measurement of microwave complex permittivity of dielectric flat plate material” IEICE Technical Report, MW87-7, pp.7-12, May 1987.
etc).

FIG. 3 shows a dielectric property measuring apparatus used for measuring the dielectric properties of the relative permittivity ε _r and the dielectric loss tangent tan δ by such a method. In FIG. 3, the dielectric property measuring device 11 has a configuration in which a plate-shaped dielectric sample 13 is sandwiched by the divided surfaces of a cavity resonator 12 made of oxygen-free copper and having a cylindrical cavity portion and which is symmetrically divided into two. The divided cavity resonators 12 are fixed to each other with screws 14 (or clips or the like). This dielectric property measuring device 11
A coaxial cable 15 is arranged as a measuring cable on the input side and the output side of the. This coaxial cable 15
A loop 16 formed by looping the central conductor of the coaxial cable 15 is provided at the tip of the. The dielectric characteristic measuring apparatus 11 measures the resonance frequency f ₀ of the TE ₀₁₁ mode, the no-load Q (Q _u ) value, and the resonance frequency f ₁ of the TE ₀₁₂ mode.

In this method, the relative permittivity ε _r of the dielectric sample 13 is calculated by the following formula (however, the correction term is omitted here).

Ε _r ≈ (c / πtf ₀ ) ² × (X ² + Y ′ ² (t / H) ² ) +1 (1) In the formula (1), X and Y ′ are relative permittivity ε _r
Is a parameter for calculating and is obtained from the following formula.

XtanX = (t / H) × Y′cothY ′ (2) Y ′ = 0.5H (k ₀ ² −k _r ² ) ^1/2 (3) Further, the above equations (2) and In Expression (3), k ₀ is the free space wave number, and k _r is the wave number in the radial direction, which is obtained from the following expression.

K ₀ = 2πf ₀ / c (4) k _r = j ₀₁ '/(0.5D) (5) In the above equations (1) to (5), f ₀ is in the TE ₀₁₁ mode. Resonance frequency (Hz), c is the speed of light (2.9979 × 1
0 ⁸ m / s), j ₀₁ ′ is the 0th-order Bessel function of the first kind J ₀ ′
(J ₀₁ ') = 0 first solution (3.8317), t is thickness of dielectric sample (mm), D is effective diameter of cavity resonator (diameter of cavity) (mm), H Is the effective height of the cavity resonator (height of the cavity) (mm).

The dielectric loss tangent tan δ is calculated from the following equation (where the correction term is omitted from the description) based on the value of the unloaded Q (Q _u ) in the TE ₀₁₁ mode.

[0010] _{tanδ ≒ A / Q u -R S} B ... (6) In the above equation (6), A and B are dielectric tangent
It is a parameter for calculating tan δ and is obtained from the following formula.

[0011] ^{_{A = 1 + W 2 e /}} W 1 e ... (7) B = The _{(P cy1 + P cy2 + P} end) ωR S W 1 e ... (8), In the above formula (6) to (8), W ₁ ^e is the stored energy of the electric field inside the dielectric sample, W ₂ ^e is the stored energy of the electric field in the cavity, P _cy1 is the conductor loss of the dielectric sample insertion part inside the cavity resonator, and P _cy2 is the cavity resonance. Of the cavity inside the cavity, P _end is the conductor loss of the end face of the cavity resonator, R _S is the surface resistance of the inner wall of the cavity resonator, and is obtained from the following equation.

W ₁ ^e = π / 8 × (ε ₀ ε _s μ ₀ ² ω ² j ₀₁ ' ² J ₀ ² (j ₀₁ ') L (1+ (sin 2X / 2X))) (9) W ₂ ^e = −π / 4 × (ε ₀ ε _s μ ₀ ² ω ² j ₀₁ ' ² J ₀ ² (j ₀₁ ') M (1- (sinh2Y / 2Y))) cos ² X / sinh ² Y '... (10 ) P _cy1 = (π / 4) R _S J ₀ ² (j ₀₁ ') LR k _r ⁴ (1+ (sin2X / 2X)) (11) P _cy2 = (π / 2) R _S J ₀ ² (j ₀₁ ') 0.5HRk _r ⁴ (1- (sin2Y / 2Y')) cos2X / sinh2Y '... (12) P _end = (π / 2) R _S J ₀ ² (j ₀₁ ') (Y '/ 0.5H ) in ^{2 (cos2X / sinh 2 Y '} ) ... (13) R S = (ωμ 0 / 2σ r σ 0) 1/2 ... (14) the above equation (9) ~ (14), ε 0 is the vacuum dielectric constant ^{(8.8540 × 10 12 F / m} ), ε s is imaginary dielectric constant of the calculation as a dielectric of the same diameter as the diameter of the cavity (yen The relative dielectric constant of the pre-effect correction), ω is the resonance angular frequency (ω
= 2πf ₀ 1 / s), σ ₀ is the electrical conductivity of international standard annealed copper at 20 ° C. (5.8 × 10 ⁷ S / m), and σ _r is the effective specific electrical conductivity (%) of the cavity resonator.

In this measurement, the effective diameter D of the cavity resonator 12, the effective height H of the cavity resonator 12, and the effective specific conductivity σ _{r of the} cavity resonator 12 are previously measured using the dielectric characteristic measuring device 11. Need to ask. Cavity resonator 12
The effective diameter D and the effective height H of using the resonance frequency f ₁ of the TE ₀₁₁ mode resonance frequency f ₀ and TE ₀₁₂ mode is calculated by the following equation.

D = (cj ₀₁ ′ / π) (3 / (4f ₀ ² −f ₁ ² )) ^1/2 (15) H = (c / 2) (3 / (f ₀ ² −f ₁ ² )) ^1/2 (16) Further, the effective specific conductivity σ _r of the cavity resonator 12 depends on the effective diameter D and the effective height H of the cavity resonator 12, the resonance frequency f ₀ of the TE ₀₁₁ mode and the no load. It is calculated by the following equation using Q (Q _u ).

Σ _r = {4πf ₀ Q _u ² (j ₀₁ ' ² + 2π ² (D / 2H) ³ ) ² } / {σ ₀ μ ₀ c ² (j ₀₁ ' ² + (πD / 2H) ² ) ³ }} (17) Here, there is a degenerate TM ₁₁₁ mode in the TE ₀₁₁ mode. This TM _{11 1} mode adversely affects the measurement of unloaded Q (Q _u ) and must be solved. Therefore, in order to separate the TE ₀₁₁ mode and the TM ₁₁₁ mode, polytetrafluoroethylene (hereinafter,
It is referred to as PTFE. A ring-shaped member (hereinafter P
It is described as a TFE ring. ) Are provided at both ends 17 of the conductor portion of the cavity resonator 12. Commonly used PT
The size of the FE ring is determined by the diameter D of the cavity resonator 12, and the ring center diameter (the diameter of the center portion of the ring width) ≈
0.48D, ring width ≈ 0.086D, ring thickness ≈
It is 0.014D. The diameter D of the cavity resonator 12 used to determine the size of the PTFE ring is the effective diameter calculated by calculation after measuring the resonance frequency and the like (affected by the surface condition inside the resonator). Differently, it is the value that can be measured with calipers.

Further, in the method of measuring the dielectric characteristics using the cavity resonator 12 as described above, the measurement frequency (TE ₀₁₁
Mode resonance frequency) is limited by the size of the cavity resonator 12, and the size and relative permittivity of the dielectric sample 13. Therefore, when it is necessary to change the frequency and measure the dielectric characteristics, a plurality of cavity resonators 12 having different sizes are prepared,
The cavity resonator 12 is changed for each measurement frequency, and the dielectric characteristic at an arbitrary resonance frequency is evaluated.

[0017]

As described above, the structure of the dielectric resonator is currently being reviewed and developed in order to obtain the dielectric resonator having a larger Q value. A cable for input and output is provided in the dielectric resonator, and a loop is provided at the tip of the cable. This loop is used to excite resonance in the resonator (cavity to be resonated) and to receive a magnetic force line and output a resonance wave. However, since this loop is located in the resonator, it has an influence on the resonance in the resonator, which also causes a decrease in the Q value. Therefore, it has been difficult to increase the Q value of the dielectric resonator.

On the other hand, in the case of the dielectric property measuring apparatus for measuring the dielectric property of the dielectric material using the cavity resonator, the size of the cavity resonator and the dielectric sample becomes smaller as the measurement frequency becomes higher, and the handling becomes easier. There was a problem that it would be difficult. For example, the size of the PTFE ring is about 20 mm in outer diameter and about 0.5 mm in thickness when the diameter of the cavity resonator is about 35 mm, and there are few handling problems. However, if the diameter of the cavity resonator is reduced to about 10 mm,
The PTFE ring has an outer diameter of about 5.7 mm and a thickness of about 0.14 m.
It becomes very small as m. It is very difficult to fix such a small circular member in a desired position with a small amount of adhesive. Therefore, if the cavity becomes smaller, P
Since the TFE ring cannot be accurately arranged at a desired position and the amount of the adhesive cannot be suppressed to be small, the adhesive has a great influence on the Q value. As a result, the effective specific conductivity σ _{r of} the cavity resonator was measured lower than actual,
The problem arises that the calculation of the relative permittivity ε _r and the dielectric loss tangent tan δ of the dielectric sample is hindered.

In order to solve these problems, the present invention provides
Providing a higher Q dielectric resonator, and
Effective specific conductivity of a cavity resonator with high accuracy even in the high frequency band
Rate σ _rCan be measured and the relative permittivity ε can be measured accurately._rAnd dissipation factor
Providing a dielectric property measuring device that can calculate tan δ
The purpose is to do.

[0020]

In order to achieve the above object, a dielectric resonator according to the present invention has a cylindrical cavity inside, and is arranged in a direction intersecting the axial direction of the cylindrical cavity. A conductor member divided into two, a dielectric member sandwiched by the divided surfaces of the conductor member, an input / output cable inserted into the conductor member, and a loop provided at the tip of the input / output cable. The area of the region surrounded by the loop is 0.001 times or less than the area of a cross section of the cylindrical cavity portion perpendicular to the axial direction.

In the conventional dielectric resonator, the area surrounded by the loop is relatively large. Therefore, the loop has a great influence on the resonance in the resonator. On the other hand, in the loop of the dielectric resonator of the present invention, the area of the region surrounded by the loop is 0.001 times or less of the area of the surface perpendicular to the axial direction of the cylindrical cavity portion. It is formed smaller than the one. In this way, by making the size of the loop smaller than that of the conventional one, it is possible to suppress the influence of the loop on the resonance in the resonator, and it is possible to realize a dielectric resonator having a higher Q value.

In order to achieve the above object, another dielectric resonator of the present invention has a cylindrical cavity inside.
A conductor member divided in two in a direction intersecting the axial direction of the cylindrical cavity, a dielectric member sandwiched by the dividing surfaces of the conductor member, an input / output cable inserted in the conductor member, and In a dielectric resonator provided with a loop provided at the tip of the input / output cable, the insertion direction of the input / output cable into the cylindrical cavity is the vertical direction, and the direction orthogonal to the vertical direction is In the lateral direction, the loop is characterized in that the ratio of the lateral inner diameter to the longitudinal inner diameter is 1 or more. However, the vertical inner diameter here is the maximum value of the vertical length of the area surrounded by the loop, and the horizontal inner diameter is the maximum value of the horizontal length of the area surrounded by the loop. .

By forming the loop into such a shape, the loop receives the magnetic field lines at a position distant from the dielectric member, so that the influence of the input / output cable on the resonance in the resonator can be suppressed to a small level. . This makes it possible to realize a dielectric resonator having a higher Q value.

The material of the conductor member is gold, silver,
It is preferable that the metal contains at least one selected from copper and aluminum. A higher Q value can be realized by using a conductor member formed of such a metal having high conductivity.

In order to achieve the above object, the dielectric property measuring apparatus of the present invention has a cylindrical hollow portion inside,
A dielectric sample comprising a conductor member divided into two parts in a direction intersecting with the axial direction of the cylindrical cavity portion, and a measurement cable inserted into the conductor member so that the tip portion reaches the inside of the cylindrical cavity portion. In the dielectric property measuring device for measuring the dielectric property of the dielectric sample by sandwiching by the divided surface of the conductor member, in the surface including the insertion part of the measurement cable in the conductor member, the insertion part of the measurement cable Avoid the
It is characterized in that a degeneration member made of a rectangular PTFE plate is provided.

Further, in the dielectric property measuring apparatus of the present invention, the degeneration member may be formed by combining a plurality of rectangular PTFE plates.

The rectangular PTFE plate is a conventional circular P
It is easier to handle than the TFE ring. Therefore, when the degeneration releasing member is provided for a small conductor member having a cylindrical hollow portion with a diameter of about 15 mm or less, the degeneration releasing member has a thickness of about 0.2 mm or less and is difficult to handle. The degeneration member made of a rectangular PTFE plate is easier to install at a desired position more accurately than the conventional PTFE ring. Furthermore, if it is a rectangular PTFE plate, even if the adhesive is applied point by point (for example, at one point), it can be bonded accurately, so it can be fixed with a small amount of adhesive compared to the conventional PTFE ring. . Therefore, the influence of the adhesive on the no-load Q (Qu) value is reduced.
In addition, if a plurality of rectangular PTFE plates are combined, the shrinkage can be effectively released at a position where the shrinkage can be effectively released (for example, a shape similar to that of a conventional PTFE ring can be obtained). The decompression releasing member can be provided by combining a rectangular PTFE plate in a concave shape. As a result, it is possible to realize a dielectric property measuring device capable of accurately measuring the dielectric property of the dielectric.

Further, in the dielectric property measuring apparatus of the present invention, the PT is provided on the entire surface of the conductor member including the inserting portion of the measuring cable, avoiding the inserting portion of the measuring cable.
It is also possible to provide a degeneration member made of an FE plate.

When the degeneration member is formed in this way,
It is easier to install than the conventional PTFE ring. Furthermore, since it is possible to accurately install even if the adhesive is applied and adhered pointwise (for example, only in the central portion), P
Less adhesive is needed than when installing a TFE ring. Therefore, it is possible to obtain an effect that the dielectric characteristics of the dielectric can be measured with high accuracy. In addition to this effect, T
Since the separability between the E ₀₁₁ mode peak and the TM ₁₁₁ mode peak is improved, the TE ₀₁₁ mode can be easily measured. If the area of the PTFE plate provided as the degeneration member is large, it is possible that the peak of each mode becomes small and the accurate peak value cannot be measured, but the separability of the peak is improved, and thus the measurement is easy, In the case of a small PTFE ring, it cannot be installed accurately on the conductor member, and since the amount of adhesive is large, a measurement error will occur. Therefore, it is possible to measure a more accurate value than when a conventional PTFE ring is installed. It is thought to be possible.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION (Embodiment 1) An embodiment of a dielectric resonator of the present invention will be described below with reference to the drawings.

The dielectric resonator of this embodiment is shown in FIG. In the dielectric resonator 1 of the present embodiment, a cavity resonator made of oxygen-free copper, which has a columnar cavity inside and is divided into two in a direction intersecting the axis (Z axis) direction of this cavity. The (conductor member) 2 holds the plate-shaped dielectric member 3 between the divided surfaces. The divided cavity resonator 2 has a screw 4
(Or clips, etc.). In the figure,
D is the diameter of the cavity portion of the cavity resonator 2 (hereinafter referred to as diameter), and H is the height of the cavity portion of the cavity resonator 2 (hereinafter referred to as height). Further, both ends 7 of the cavity resonator 2 are provided with input / output cable insertion holes symmetrically at a position of a quarter of the diameter D, and the coaxial cable 5 is arranged as an input / output cable. ing.

Coaxial cable 5 inserted in the cavity resonator 2
A loop 6 is provided at the tip of the. This loop 6
Depends on the size of the loop to be formed, as shown in FIG.
The central conductor of the coaxial cable 5 by the length
Secure the tip to the outer conductor of the coaxial cable 5 with solder 8
It is formed by making it into a cup shape. In addition, in FIG.
In order to clearly show the shape of the loop 6, it is shown in FIG.
A loop 6 is shown when the dielectric resonator 1 is viewed from the top side.
Has been. The area of the loop 6 in the loop 6 is Z of the hollow portion.
Area of a plane perpendicular to the axial direction (using the diameter D of the cavity resonator 2
When (D / 2) ²becomes π. ) Less than 0.001 times
Is formed. The loop 6 is shown in FIG.
The shape is not limited to a circular shape, and even a circular shape (circle, ellipse) is rectangular.
It may have a shape.

The other end of the coaxial cable 5 is
It is connected to the center conductor of a V cable (not shown), and is further connected to the network analyzer via this V cable.

The material used for the dielectric member 3 is not particularly limited, and any dielectric material can be used.

In the dielectric resonator of this embodiment, the area of the region surrounded by the loop 6 is 0.001 times or less of the area of the surface of the cavity of the cavity resonator 2 which is perpendicular to the Z-axis direction. Since it is smaller than the loop, the influence of the loop on the resonance in the resonator can be suppressed, and a higher Q value than that of the conventional dielectric resonator can be obtained.

In this embodiment, the cavity resonator 2 is made of oxygen-free copper, but in addition to copper, gold,
Any metal having high conductivity such as silver, aluminum, or an alloy of these metals can be used. By using the cavity resonator 2 made of a metal having a high conductivity in this way, a higher Q value can be obtained than when using a cavity resonator made of a metal having a low conductivity.

(Embodiment 2) An embodiment of the dielectric resonator of the present invention will be described. The dielectric resonator of the present embodiment is the same as the dielectric resonator of Embodiment 1 except for the loop 6, and therefore the description of the structure other than the loop 6 is omitted here.

The loop 6 in this embodiment has an inner diameter in the horizontal direction (indicated by a in FIG. 2) and a vertical direction when the insertion direction of the coaxial cable 5 into the cavity resonator 2 is the vertical direction. The inner diameter (indicated by b in FIG. 2) ratio (horizontal inner diameter / vertical inner diameter (a / b)) is 1 or more. When the loop 6 has such a shape, the loop 6 picks up a magnetic field line at a position distant from the dielectric member 3, so that the resonance of the coaxial cable 5 is less disturbed. Therefore, a Q value higher than that of the conventional dielectric resonator can be obtained.

Although the loop 6 shown in FIG. 2 has a circular shape, it is not limited to this and the loop 6 may have a rectangular shape, for example.

(Embodiment 3) An embodiment of the dielectric property measuring apparatus of the present invention will be described below with reference to the drawings.

The dielectric property measuring apparatus 11 of this embodiment is shown in FIG.
The structure is substantially the same as that of the conventional dielectric characteristic measuring apparatus, except that both ends 1 of the cavity resonator (conductor member) 12 are
The shape of the degeneration member provided in 7 is different from the conventional one. FIG. 4 (a) shows the degeneration member 18 in the dielectric property measuring apparatus of this embodiment, and FIG. 4 (b) shows the PTFE ring provided as the degeneration member in the conventional dielectric property measuring apparatus. 19 is shown.

The contraction releasing member 18 in this embodiment is
Provided by arranging three rectangular PTFE sheets (PTFE plates) in combination in a concave shape except for the insertion hole portion (insertion portion of the measurement cable) of the coaxial cable 15 provided as the measurement cable. Has been.

As described above, the contraction releasing member is replaced with the conventional PT.
By combining the FE ring 19 with a rectangular sheet that is easy to handle, it can be easily and accurately installed at a desired position, and even if it is point-wise adhered, it can be accurately adhered to the conventional PTFE ring. It can be fixed with a smaller amount of adhesive than 19. Also,
Since the degeneration member 18 has a shape close to that of the conventional PTFE ring 19, the degeneration can be effectively released as in the case of the PTFE ring 19. Therefore, the effective specific conductivity σ _r of the cavity resonator 12 can be accurately measured. As a result, the relative permittivity ε _r and the dielectric loss tangent tan δ of the dielectric sample 13 can be calculated accurately. The method of calculating the relative permittivity ε _r and the dielectric loss tangent tan δ is as described in the related art.

Further, in the present embodiment, three rectangular PTFE sheets are used as the shrinkage releasing member, but the number of rectangular PTFE sheets is not limited to three, and a plurality of rectangular PTFE sheets may be arranged in combination to release the shrinkage. It can also be used as a member.

Further, at both ends 17 of the cavity resonator 12,
The entire surface including the insertion hole of the coaxial cable 15 is PTFE.
Sheets can also be arranged. In this case, in addition to the effect obtained when the three rectangular PTFE sheets are combined as shown in FIG. 4A, the separability between the TE ₀₁₁ mode peak and the TM ₁₁₁ mode peak is improved. It is also possible to obtain the effect of easy measurement.

[0046]

EXAMPLES The present invention will be specifically described below with reference to examples.

(Examples 1 and 2 and Comparative Examples 1) Examples 1 and 2 are examples of the dielectric resonator 1 described in Embodiment 1, and Comparative Example 1 is a comparison with Examples 1 and 2. Here is an example.

The cavity resonator 2 is made of oxygen-free copper, and
The diameter D is 12 mm, and the height (H / 2) of one half is
It was 4.29 mm. Both ends 7 of the cavity resonator 2 are left and right.
I / O cable insertion holes with a diameter of 0.9 mm are provided symmetrically
It was being done. The dielectric member 3 is 14 mm square and has a thickness
Processed to 0.40 mm, relative permittivity 7.8, Q × f = 9
000GHz Al-Mg-Si-Ge based glass ceramics
Kuk material was used. Insertion of input / output cable for cavity 2
The coaxial cable 5 having an outer diameter of 0.58 mm is inserted into the hole.
Was there. For the coaxial cable 5, the area inside the loop 6
Is 0.00016 of the area of the plane perpendicular to the Z-axis direction of the cavity.
Double (Example 1), 0.001 (Example 2), 0.00
Prepared three types of 35 times (Comparative Example 1), each
About TE ₀₁₁The Q value of the resonance peak of the mode was measured.
The coaxial cable 5 is connected via the V cable.
The network analyzer is HEWLETT PACKARD 8
722A was used.

As a result, the resonance frequency was 26 GHz and the Q value was as shown in Table 1. In addition, in Table 1, the area of the region surrounded by the loop 6 is described as “area in the loop”, and the area of the surface of the cavity portion perpendicular to the Z-axis direction is described as “area of the cavity portion”.

[0050]     (Table 1)       ―――――――――――――――――――――――――――――――                       Area in loop / area of cavity Q value       ―――――――――――――――――――――――――――――――         Example 1 0.00016 480         Example 2 0.001 450         Comparative Example 1 0.0035 390       ―――――――――――――――――――――――――――――――

From this, it was confirmed that a high Q value can be obtained when the area of the region surrounded by the loop 6 is 0.001 times or less of the area of the surface of the cavity portion perpendicular to the Z-axis direction.

(Examples 3 and 4 and Comparative Example 2) Examples 3 and 4 are examples of the dielectric resonator described in Embodiment 2, and Comparative Example 2 is a comparative example with respect to Examples 3 and 4. is there.

Regarding the coaxial cable 5 here, the inner diameter of the loop 6 provided at the tip is 0.1 mm in length-0.4 m in width.
m (Example 3), vertical 0.2 mm-horizontal 0.2 mm (Example 4), vertical 0.4 mm-horizontal 0.1 mm (Comparative Example 2), such as an ellipse or a circle having the same area in the loop 6. Three types of loops were prepared, and the Q value of the resonance peak of the TE ₀₁₁ mode was measured for each. In addition, except the shape of the loop 6,
All were the same as in Examples 1 and 2 and Comparative Example 1.

As a result, the resonance frequency was 26 GHz and the Q value was as shown in Table 2.

[0055]     (Table 2)       ――――――――――――――――――――――――――――                         Loop inner diameter (mm) Q value       ――――――――――――――――――――――――――――         Example 3 Vertical 0.1-horizontal 0.4 500         Example 4 0.2 in length-0.2 in width 460         Comparative Example 2 Vertical 0.4-Horizontal 0.1 420       ――――――――――――――――――――――――――――

From this, it was confirmed that a high Q value was obtained when the ratio of the inner diameter in the lateral direction / the inner diameter in the longitudinal direction of the loop 6 was 1 or more.

Further, an iron cavity resonator 2 having the same size was produced, and the Q value of the dielectric resonator was measured using the coaxial cable 5 prepared as Example 4, and the result was 380. The conductivity of copper is 5.8 × 10 ⁷ (S · m ⁻¹ ), whereas the conductivity of iron is 9.8 × 10 ⁶ (S · m ⁻¹ ).
This is because the Q value was lowered because it was m ⁻¹ ). Therefore, it was confirmed that in order to obtain a high Q value, it is preferable to manufacture the cavity resonator 2 with a metal having high conductivity.

(Examples 5 and 6 and Comparative Example 3) Examples 5 and 6 are examples of the dielectric characteristic measuring apparatus described in Embodiment 3, and Comparative Example 3 is a comparison with Examples 5 and 6. Here is an example. Here, the cavity resonators used in Examples 1 to 4 and Comparative Examples 1 and 2 are used as the cavity resonator 12, and the inner diameter of the loop 16 as the measuring cable is 0.1 in the vertical direction.
A coaxial cable 15 having a size of mm-0.4 mm was used.
Further, the samples used as the dielectric members in Examples 1 to 4 and Comparative Examples 1 and 2 were used as the dielectric sample 13, and the relative permittivity ε _r and the dielectric loss tangent tan δ of this dielectric sample (glass ceramic material) were measured. .

First, in order to obtain the effective size (effective diameter D and effective height H) and the effective specific conductivity σ _r of the cavity resonator 12, the TE of the cavity resonator 12 is held without sandwiching the glass ceramic material. _{The 011} mode resonance frequency f ₀ and the unloaded Q (Q _u ) value and the TE ₀₁₂ mode resonance frequency f ₁ were measured. At this time, as a degeneration member, a combination of three rectangular PTFE sheets in a concave shape (Example 5), the entire surface of both ends 17 of the cavity resonator 12 (however, the insertion hole of the coaxial cable 15 is PTFE (excluding part)
A dielectric property measuring device 11 in which a circular sheet (Example 6) and a conventional PTFE ring (Comparative Example 3) were arranged was prepared, and measurement was performed using these three types of dielectric property measuring devices.

The size of the PTFE ring used as the comparative example 3 is determined by the diameter D of the cavity resonator 12, that is, the center diameter of the ring is approximately 0.48D and the ring width is the same as conventionally used. ≈0.086D and ring thickness ≈0.014D. As shown in Examples 1 to 3 and Comparative Examples 1 and 2, the cavity resonator 12 used here is used.
Since the diameter D is 12 mm, the ring center diameter is approximately 5.7.
6 mm, ring width ≈ 1.032 mm, ring thickness ≈ 0.
It becomes 168 mm. Therefore, here, the ring center diameter is 1.05 mm, the ring width is 0.15 mm, and the ring thickness is 0.
A 2 mm PTFE ring was used.

The thickness of the PTFE sheets of Examples 5 and 6 is
It was set to 0.2 mm like the PTFE ring of Comparative Example 3.
Further, in Example 5, three rectangular PTFE sheets are used, and the size thereof is 6 mm in length × 1 mm in width, 2 in length, and 4 in length.
mm × width 1 mm was taken as one sheet.

The Q value of the cavity resonator 12 was measured using these three types of dielectric characteristic measuring devices, and the effective specific conductivity σ _r of each was calculated using equation (17). The results were obtained. The T of the cavity resonator 12
The resonance frequency of the E ₀₁₁ mode was 35 GHz.

[0063]     (Table 3)       ―――――――――――――――――――――――――――――――                         Degeneration release member Effective specific conductivity (%)       ―――――――――――――――――――――――――――――――         Example 5 Recessed PTFE sheet 72         Example 6 Full surface PTFE sheet 84         Comparative Example 3 PTFE ring 23       ―――――――――――――――――――――――――――――――

The degeneration releasing member, which has been a ring shape in the past, is
By forming a shape in which a plurality of rectangular sheets are combined or a shape in which the entire surfaces of both ends 17 of the cavity resonator 12 are covered with a sheet, the sheet can be easily installed at a desired position, and an adhesive is applied in points. It was confirmed that the effective specific conductivity σ _r can be measured with high accuracy because the adhesive could be fixed with a small amount of adhesive.

Next, the dielectric property measuring device 11 provided with the whole PTFE sheet of Example 6 and the PTFE of Comparative Example 3 were used.
FIG. 5 shows a result obtained by analyzing the dielectric property measuring device provided with the ring and the dielectric property measuring device not provided with the degeneration member by the electromagnetic field simulator. In the figure, the full-faced PTFE sheet is the result of analysis in the state where the PTFE circular sheet is fixed to the end face 17 of the cavity resonator 12 in an ideal state. On the other hand, the full-face PTFE sheet (gap between the wall surface and 0.2 mm) is indicated because the PTFE circular sheet is only partially fixed to the end face 17 of the cavity resonator 12 or the thickness of the adhesive. Is a result of analysis in the state where there is a gap of about 2 mm between the PTFE circular sheet and the end face 17 of the cavity resonator 12. Based on this result, the PTF provided as the degeneration releasing member
When the E member is shaped so as to cover the entire ends 17 of the cavity resonator 12, the separability between the peaks of the TM ₁₁₁ mode and the TE ₀₁₁ mode is improved, and the TE ₀₁₁ mode can be easily measured. confirmed. Further, even when the PTFE circular sheet is slightly floating from the end portion 17 of the cavity resonator 12, good results are obtained as compared with the conventional PTFE ring.

[0066]

As described above, according to the dielectric resonator of the present invention, a dielectric resonator having a higher Q value can be obtained by an easy method. Further, according to the dielectric property measuring apparatus of the present invention, the effective specific conductivity of the cavity resonator can be accurately obtained, so that the dielectric property of the microwave dielectric ceramic material can be accurately evaluated.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of a dielectric resonator according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a coaxial cable and a loop in the dielectric resonator according to the embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a schematic configuration of a dielectric property measuring apparatus according to an embodiment of the present invention.

FIG. 4A is a diagram illustrating a degeneration releasing member of the dielectric property measuring apparatus of the present invention, and FIG. 4B is a diagram illustrating a degeneration releasing member of the conventional dielectric property measuring apparatus.

5 is a frequency response obtained when an electromagnetic field simulator was used to analyze the dielectric property measuring apparatus of Example 6, the dielectric property measuring apparatus of Comparative Example 3, and the dielectric property measuring apparatus not provided with a degeneration member. It is a figure which shows the mode discrimination by the resonance frequency calculated by the mode chart.

[Explanation of symbols]

1 Dielectric resonator 2 cavity resonator 3 Dielectric member 4 screws 5 coaxial cable 6 loops 7 Cavity resonator end of conductor 8 solder 11 Dielectric property measuring device 12 cavity resonator 13 Dielectric sample 14 screws 15 coaxial cable 16 loops 17 End of conductor part of cavity resonator 18 Degeneration release member 19 PTFE ring

Continued front page    (72) Inventor Akira Enohara             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F term (reference) 2G028 AA01 BB05 BC01 CG09 CG10                       DH15 EJ01 FK03                 5J006 HC01 HC03 HC12 LA02 NA02                       PA01

Claims (7)

[Claims] 1. A conductor member having a cylindrical hollow portion inside thereof, which is divided into two in a direction intersecting the axial direction of the cylindrical hollow portion, and a dielectric member sandwiched between the divided surfaces of the conductor member. ,
In a dielectric resonator including an input / output cable inserted in the conductor member and a loop provided at a tip end portion of the input / output cable, an area of a region surrounded by the loop is the cylindrical shape. A dielectric resonator, wherein the area of the cavity is 0.001 times or less the area of a cross section of the cavity perpendicular to the axial direction. 2. A conductor member having a cylindrical hollow portion inside and divided into two in a direction intersecting with the axial direction of the cylindrical hollow portion, and a dielectric member sandwiched by the divided surfaces of the conductor member. ,
A dielectric resonator comprising an input / output cable inserted into the conductor member and a loop provided at a tip of the input / output cable, wherein the input / output cable is inserted into the cylindrical cavity portion. The dielectric resonator, wherein the loop has a ratio of the inner diameter in the horizontal direction to the inner diameter in the vertical direction of 1 or more, where the direction is the vertical direction and the direction orthogonal to the vertical direction is the horizontal direction. 3. The dielectric resonator according to claim 1, wherein the material of the conductor member is a metal containing at least one selected from gold, silver, copper, and aluminum. . 4. A conductor member having a cylindrical hollow portion inside, divided into two in a direction intersecting the axial direction of the cylindrical hollow portion, and a measurement cable inserted into the conductor member, In a dielectric property measuring device for measuring a dielectric property of the dielectric sample by sandwiching a dielectric sample between divided surfaces of the conductor member, a measurement cable is provided on a surface of the conductor member including an insertion portion of the measurement cable. A dielectric property measuring device, characterized in that a degeneracy releasing member made of a rectangular polytetrafluoroethylene plate is provided so as to avoid the insertion part. 5. The dielectric property measuring device according to claim 4, wherein the degeneration releasing member is formed by combining a plurality of rectangular polytetrafluoroethylene plates. 6. The dielectric property measuring device according to claim 5, wherein the degeneration releasing member is provided in a concave shape. 7. A conductor member having a columnar hollow portion inside and divided into two in a direction intersecting the axial direction of the columnar hollow portion, and a measurement cable inserted into the conductor member. In the dielectric property measuring device for measuring the dielectric property of the dielectric sample by sandwiching the dielectric sample between the divided surfaces of the conductor member, the whole surface of the conductor member including the insertion portion of the measurement cable is Avoid the insertion part of the measurement cable,
An apparatus for measuring dielectric properties, comprising a degeneration member made of a polytetrafluoroethylene plate.