JP4710082B2 - Method and apparatus for measuring dielectric constant using microwaves - Google Patents

Description

  The present invention relates to a measuring method for irradiating an object to be measured with microwave power and measuring a dielectric constant of the object to be measured and a measuring apparatus therefor.

  There are a waveguide method, a resonator method, a free space method, and the like as a method for measuring material characteristics (complex dielectric constant ε, complex magnetic permeability μ) of a dielectric material and a magnetic material using a microwave.

  Among these measurement methods, the resonator method is a method in which an object to be measured is inserted into a resonator that supplies microwave power, and measurement is performed based on the perturbation method. The resonance frequency of the microwave before and after insertion of the object to be measured. And the change in Q indicating the resonance effect is measured, and the material properties are calculated from the measured values.

Therefore, in this resonator method, since it is assumed that the material characteristics of the object to be measured are constant and the electromagnetic field in the resonator is not disturbed, the average material characteristic value of the object to be measured can be obtained. Stop.
For this reason, even if several measurements are attempted, only an average value of the material characteristics can be obtained, and it has not been possible to measure a deviation in the material characteristics of the object to be measured, a change in the material characteristics due to the temperature of the object to be measured, or the like.

Specifically, when the dielectric is irradiated with microwaves, the power Pv absorbed by the dielectric is obtained by the following equation.
Pv = 5/9 · fE ² ε′rtan δ × 10 ⁻¹⁰ (w / m ³ )
f: Frequency (Hz)
E: Electric field strength (V / m)
ε′r: relative dielectric constant
tan δ: dielectric loss tangent

  As can be seen from this equation, the heating state of the dielectric changes greatly due to changes in ε'r and tan δ. Since these ε'r and tan δ affect the frequency of the microwave and the temperature of the dielectric, complex dielectrics are used as material properties. It is important to obtain the rate ε in detail.

Material constant measurement method in the high frequency region "Issuing place Morikita Publishing Co., Ltd., August 26, 2003, first edition"

  In view of the above situation, in the present invention, a measurement method using a microwave capable of obtaining a complex dielectric constant ε corresponding to a material property deviation of a dielectric material to be measured and a change in material properties due to temperature, and its An object is to provide a measuring device.

In order to achieve the above object, in the present invention, as a first invention, a measurement method for measuring a dielectric constant of a measurement object by a perturbation method by inserting the measurement object into a cavity resonator for supplying microwave power In the cavity resonator, a first step of inserting at least two objects to be measured M ₁ , M ₂ ... M _n into the cavity resonator, and before and after the objects to be measured are inserted. resonance angular frequency omega _o of the microwave, ω _{L, Q} o indicating the resonance effect, _{Q L,} a second for measuring the field strength _{E 1, E} 2 _{····· E n} of the insertion position of the object to be measured each A step, a third step of repeating the second step by changing the position of the object to be measured according to the number of objects to be measured, and the ω _o , ω _L , Q _o , Q _L , E ₁ , E _2. E _n a cavity resonator volume V, the fourth for calculating the dielectric constant of each more measured object and the measured object each volume △ V We propose a method of measuring the dielectric constant using the microwave; and a degree.

As a second invention, in the measurement method according to the first invention, the second step includes the resonance angular frequencies ω _o and ω _L of the microwaves in the cavity resonator before and after the measurement object is inserted, and the resonance effect. Q _o , Q _L indicating the length of the cavity resonators a, L, resonance angular frequency ω _o , ω _L , vacuum permeability μo field strength of the position E _1, E ₂ ····· proposes a method of measuring the dielectric constant using a microwave characterized by comprising a calculation step of calculating an E _n.

According to a third aspect of the present invention, there is provided a measuring method in which a measured object is inserted into a cavity resonator for supplying microwave power and the dielectric constant of the measured object is measured by a perturbation method. _First division step for determining virtual division positions P ₁ , P ₂ ... P _n, and before and after insertion of the object to be measured, resonance angular frequencies ω _o , ω _L , and microwave resonance frequencies of the microwaves in the cavity resonator _Q o indicating the resonance effect, _{Q L,} and a second step of measuring the virtual division position of each of the electric field strength _{E 1, E} 2 _{····· E n} of the object to be measured, according to the number of the division position of the object to be measured a third step of repeating the second step changes the position of the object to be measured Te, wherein _{ω o, ω L, Q o} , the volume of _{Q L, E 1, E 2} ····· E n and the cavity resonator A fourth step of calculating a dielectric constant at each of the division positions of the object to be measured from V, the volume ΔV of the virtual division position of the object to be measured; We propose a method of measuring the dielectric constant using a microwave comprising.

As a fourth invention, in the measurement method of the third invention, in the second step, the resonance angular frequencies ω _o and ω _L of the microwaves in the cavity resonator before and after the measurement object is inserted, The measurement of Q _o and Q _L indicating the effect, the longitudinal and lateral lengths a and L of the cavity, the resonance angular frequencies ω _o and ω _L , and the vacuum permeability μo Suggest dielectric constant measuring method using a microwave characterized by comprising a calculation step of calculating a virtual division position of each of the electric field strength _{E 1, E 2 ····· E n} .

As a fifth invention, in the measurement method of the first or third invention described above, the second step includes resonance angular frequencies ω _o , ω _L , Q _o , Q _L , and electric field indicating resonance effects in the initial measurement. the intensity _{E 1, E} 2 _{····· E n} is measured, the dielectric constant using a microwave initial measurement after is characterized by measuring the electric field strength _{E 1, E} 2 _{····· E n} A measurement method is proposed.

According to a sixth aspect of the present invention, in a measuring apparatus for measuring a dielectric constant of a measured object by a perturbation method by inserting the measured object into a cavity resonator that supplies microwave power, the measured object is inserted into the cavity resonator. At least two or more objects to be measured, and before and after inserting the objects to be measured, resonance angular frequencies ω _o and ω _L of microwaves in the cavity resonator, Q _o and Q _L indicating resonance effects, and the object to be measured measuring means for measuring the field strength E _1, E ₂ ····· E _n for each insertion position, and a control means to repeat the measurement by said measuring means change the position of the object to be measured according to the measurement object number the _{ω o, ω L, Q o} , Q L, E 1, E 2 ····· E n and the cavity resonator volume V, each more measured object and the measured object each volume △ V The dielectric constant using microwaves is characterized by comprising a computing means for calculating the dielectric constant. To propose a constant apparatus.

As a seventh invention, in the measurement apparatus according to the sixth invention, the measurement means is configured to measure the resonance angular frequencies ω _o and ω _L of the microwaves in the cavity resonator before and after the measurement object is inserted. The measurement of Q _o and Q _L indicating the effect, the longitudinal and lateral lengths a and L of the cavity, the resonance angular frequencies ω _o and ω _L , and the vacuum permeability μo Suggest dielectric constant of a measuring device using microwaves, characterized in that comprising a calculating means for calculating a field intensity E _1, E ₂ ····· E _n of the insertion position.

According to an eighth aspect of the present invention, there is provided a measurement apparatus for measuring a dielectric constant of a measured object by a perturbation method by inserting the measured object into a cavity resonator that supplies microwave power, and at least two or more virtual divisions position P _1, P ₂ · · · · · and P DUT _{of n} defining the, before and after insertion of an object to be measured, the microwave resonance angular frequency omega _o within said cavity _resonator, omega _L, the resonance effect the illustrated Q _o, Q _L, and measuring means for measuring a virtual division position of each of the electric field strength E _1, E ₂ ····· E _n of the object to be measured according to the number of the division position of the object to be measured control means for repeating the measurement by said measuring means changing the position of the object, the _{ω o, ω L, Q o} , Q L, E 1, E 2 ····· E n and the cavity resonator volume V, Calculation for calculating the dielectric constant of each divided position of the measured object from the volume ΔV of the virtual divided position of the measured object Suggest dielectric constant of a measuring device using microwaves, characterized in that comprising a stage.

As a ninth invention, in the measurement apparatus according to the eighth invention described above, the measurement means is configured such that the resonance angular frequencies ω _o , ω _L , and microwave resonance frequencies of the microwave in the cavity resonator before and after the measurement object is inserted. Q _o indicating the resonance _effect, means for measuring the Q _L, the cavity resonator of the vertical and horizontal length a, L, the resonance angular frequency omega _o, omega _L, the object to be measured based on the magnetic permeability μo of the vacuum Suggest dielectric constant of a measuring device using microwaves, characterized in that comprising a virtual division position of each of the electric field strength E _1, calculating means for calculating E ₂ ····· E _n.

According to a tenth aspect of the invention, in the measurement apparatus according to any one of the sixth to ninth aspects, a TE _103- mode rectangular cavity resonator is provided as the cavity resonator. A device for measuring dielectric constant using waves is proposed.

According to the present invention, the material properties of various types of objects to be measured can be measured under the same measurement conditions, which is advantageous in specific comparison of objects to be measured, and also has a dielectric constant that is greater than or equal to a predetermined value. Since objects can be sorted out, it is possible to know a material that becomes a defective product.
Further, according to the present invention, since the material characteristics at each virtual division position of the object to be measured can be measured, the deviation of the material characteristics can be detailed.
Specifically, it is possible to know the material specific bias of the cut surface of the object to be measured.

  In addition, the material property of the measured object having temperature dependence changes greatly as the imaginary part of the complex dielectric constant ε increases with increasing temperature. According to the present invention, the real part and the imaginary part of the complex dielectric constant ε Therefore, it is possible to measure the material characteristics of the microwave heated dielectric material with high accuracy.

Next, an embodiment of the present invention will be described. In this embodiment, since measurement is performed according to the perturbation method, measurement of the perturbation method will be described first.
In the perturbation method, it is assumed that the device under test is small and the electromagnetic field in the resonator is the same before and after insertion of the device under test, and the following equation is derived from the Maxwell equation.

ωｏ： 被測定物挿入前の共振角周波数
ω ： 被測定物挿入後の共振角周波数
Ｖ ： 共振器の体積
△Ｖ： 被測定物の体積
εｏ： 真空中の誘電率
εｒ： 比誘電率
μｏ： 真空中の誘磁率
Ｅｏ： 被測定物挿入前の電界
Ｅ ： 被測定物挿入後の電界
Ｈｏ： 被測定物挿入前の磁界

ωo: Resonant angular frequency before the measurement object is inserted
ω: Resonant angular frequency after the measurement object is inserted
V: Volume of the resonator
ΔV: Volume of measured object
εo: Dielectric constant in vacuum
εr: relative dielectric constant
μo: Magnetic reluctance in vacuum
Eo: Electric field before measurement object is inserted
E: Electric field after measurement object is inserted
Ho: Magnetic field before measurement object is inserted

Further, since the electric field energy and the magnetic field energy are equal in the resonance state, the following equation is obtained.

ここで、ＬはＺ方向の長さ、ａはＸ方向の長さ、Ｃは常数である。 Further, when the TE ₁₀₃ mode cavity resonator is used, the electromagnetic field components in the resonator are only Ey, Hx, and Hz, so that the electromagnetic field components can be expressed by the following equations. .

Here, L is the length in the Z direction, a is the length in the X direction, and C is a constant.

ここで、添え字ｒとｉは実数部と虚数部を表し、Ｑ_Ｌは負荷のＱである。 When the complex frequency is considered, the angular frequency when the cavity resonator resonates is as follows.

Here, the subscripts r and i represent the real part and the imaginary part, and Q _L is the load Q.

ここで、添え字０は被測定物挿入前の状態であり、添え字１は被測定物挿入後の状態を示す。 When the object to be measured is inserted into the cavity resonator in the resonance state, the complex resonance angular frequency changes, and the following equation is obtained from the above equation (2).

Here, the subscript 0 indicates a state before the measurement object is inserted, and the subscript 1 indicates a state after the measurement object is inserted.

ここでε′ｒとε″ｒは、複素誘電率の実数部と虚数部とを表わす。 Therefore, the following equation can be obtained from the above equations (2) and (5).

Here, ε′r and ε ″ r represent a real part and an imaginary part of the complex permittivity.

Therefore, the volume V of the resonator, the volume ΔV of the object to be measured, ωo, Qo before insertion of the object to be measured, ω _L , Q _L after insertion of the object to be measured are measured, and the maximum electric field strength Eo is obtained. If it calculates | requires, a complex dielectric constant can be calculated from said (6) Formula.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a cavity resonator 10 used as a measurement method and a measurement apparatus according to the first embodiment, a network analyzer-11, and measured objects A and B. FIG. 2 shows a cavity resonator 10. FIG. 3 and FIG. 4 are simplified plan views of the cavity resonator 10 for explaining the measurement operation.

In the present embodiment, as shown in FIG. 2, the cavity resonator 10 has a length a in the X direction a = 109.2 mm, a length b in the Y direction = 27.3 mm, and a length L in the Z direction L = 221.8 mm. The rectangular cavity resonator is used, and microwave power is supplied to the cavity resonator 10 in the TE ₁₀₃ mode.

  On the other hand, in the present embodiment, two kinds of measurement objects A and B (for example, a ceramic and a metal oxide ceramic) having a round bar shape are inserted into the cavity resonator from the insertion port 10a, and these objects are measured according to the perturbation method described above. The material properties (complex dielectric constant) of the measurement objects A and B are measured.

被測定物Ｂは、被測定物Ａの横に挿入する。
なお、被測定物ＡとＢの間隔は図２に示すようにｄとする。 As shown in FIG. 3, the device under test A is inserted at a position where X = a / 2 and Z = L / 2, where the electric field is maximum and the magnetic field is zero.
This insertion position is an electric field Eo of microwave power of TE ₁₀₃ mode, and can be expressed by the following equation as its maximum amplitude Ao.

The object to be measured B is inserted beside the object to be measured A.
Note that the distance between the objects A and B is d as shown in FIG.

ここでＶは空胴共振器１０の体積、△ＶＡ、△ＶＢは被測定物Ａ、Ｂの体積、ε′ｒ_Ａとε′ｒ_Ｂは被測定物ＡとＢの複素比誘電率の実数部である。 And this embodiment which measures on the insertion conditions of the display measurement objects A and B shown in FIG. 2 first obtains the following equation from the perturbation formula (2).

Where V is the volume of the cavity resonator 10, ΔVA and ΔVB are the volumes of the objects _A and _B to be measured, and ε′r _A and ε′r _B are the real numbers of the complex relative dielectric constants of the objects A and B. Part.

この（９）式において、

In order to simplify the above equation (8), ωr ₁ −ωo / ωro = Δω,
When (ε′r _A −1) = Δε′r _A and (ε′r _B −1) = ε′r _B , the following equation is obtained.

In this equation (9),

Further, assuming that the electric field is uniform at the insertion position of the object to be measured, since the object A to be measured is at the maximum electric field position, Eo = Ao, and E ₁ = Ao at the insertion position of the object B to be measured. _COS (3πd / L).
Therefore, the volume integration is as follows.

Substituting the above expressions (10) and (11) into the perturbation formula of the above expression (9) yields the following expression.

In the present embodiment, the amount of change (Δω ₁ ) in the complex resonance angular frequency before and after the objects to be measured A and B are inserted as shown in FIG. 3 is measured.
That is, the complex resonance angular frequency Δω ₁ is obtained by measuring changes in the resonance frequency and the Q value.
Thereafter, the positions of the objects to be measured A and B are exchanged as shown in FIG. 4, and the complex resonance frequency Δω ₂ is obtained in the same manner as described above.

The following simultaneous equations are obtained from the above measurement results and the above equation (12).

Solving these simultaneous equations,

Therefore, the solid line part of the complex dielectric constant is obtained from the following equation from ε′r _A = 1 + Δε′r _A.

Similarly, the imaginary part of the complex dielectric constant can be obtained from the following equation.

Here, ΔQ = (1 / Q _L1 −1 / Q _L2 ). Subscript 1 is when the measured objects A and B are at the insertion position in FIG. 3, and subscript 2 is when the measured objects A and B are at the insertion position in FIG.
As can be seen from the above, the complex permittivity of each of the two types of measured objects A and B can be obtained.
Incidentally, the electric field strength Eo, for E ₁ can also be determined by measuring the addition obtained by calculation by Equation (11).

5 and 6 show a second embodiment in which the complex dielectric constants of four round-bar-shaped objects to be measured M ₁ , M ₂ , M ₃ , and M ₄ are similarly measured.
FIGS. 5 and 6 are simplified plan views of the cavity resonator 10 similar to FIGS.

When implemented in this way, the insertion positions of the objects to be measured M _{1 to} M ₄ are obtained from the X and Z coordinates.
That is, in the case of FIG. 5, the M1 position is (X ₁₁ , Z ₁₁ ), the M2 position is (X ₁₂ , Z ₁₂ ), the M3 position is (X ₁₃ , Z ₁₃ ), and the M4 position is (X ₁₄ , Z _14). ), The insertion positions d ₁₁ , d ₁₂ , d ₁₃ and d ₁₄ of the object to be measured are obtained.

Thus, if the insertion position of the object to be measured is determined, the distance between the objects to be measured M _{1 to} M ₄ can be specified. Therefore, the specific distance is defined as d in the above formulas (15) and (16). ε′r ₁ , ε′r ₂ , ε′r ₃ , and ε′r ₄ can be derived to determine the complex dielectric constant of each of the objects to be measured M _{1 to} M ₄ .

7 and 8 show a third embodiment.
In the present embodiment, a single device under test 21 is inserted into the cavity resonator 10, the inside of the device under test 21 is divided into a plurality of parts, and the complex dielectric constant of each part is measured.

FIG. 7 shows an example of a rotating plate 22 on which the object 21 to be measured is placed. The rotating plate 22 is provided so as to rotate intermittently around the rotating shaft 23 in the cavity resonator 10.
That is, the rotating plate 22 is intermittently rotated, and the change amount Δω of the complex resonance angular frequency is measured at each rotational position.

FIG. 8 shows a virtual division state of the DUT 21, and P ₁ , P _2, ... Pn indicate virtual division sections (division positions).
Note that the number of divisions can be arbitrarily determined.
Further, the positions of the virtual divided sections P ₁ , P ₂ ... Pn divided in this way can be obtained according to the XZ coordinates in the same manner as described above.

ただし、添え字１〜ｍは測定回数、△Ｖ_１〜△Ｖｎは仮想分割区分の体積、Ｅ_１１〜Ｅ_１ｎ〜Ｅ_ｍ１〜Ｅ_ｍｎは仮想分割区分各々の電界強度である。 In the present embodiment configured as described above, the rotation plate 22 is slightly rotated by m (within one rotation), and the amount of change Δω ₁ , Δω of the resonance angular frequency before and after insertion of the DUT 21 for each rotation position. _2. Measure Δωm.
From this, the following equation is obtained according to the equation (9).

However, subscripts ₁ to _m are the number of measurements, ΔV ₁ to ΔVn are the volumes of the virtual divided sections, and E _{11 to} E _{1n to} E _{m1 to} E _mn are the electric field strengths of the virtual divided sections.

Therefore, in the same manner as the above equations (15) and (16), the real part ε′r ₁ , ε′r ₂ ... Ε′r _{n of the} complex permittivity and the imaginary part ε from the above equation (17). _{"r 1,} ε" it is possible to obtain the _r 2 ····· ε "r _n.
Note that the relationship between the number of times of measurement m and the number of virtual division sections n can be measured when m ≧ n. For example, each equation of m times can be calculated by applying, for example, the least square method to obtain the total error. it can be obtained ε'r ₁ ~ε'r _n that minimizes.

  In addition to metal materials such as ceramics and metal oxide ceramics, it can be used in measurement methods and measuring devices for measuring the state of internal moisture such as foods, wood, concrete, and the like.

It is the figure which showed the cavity resonator and network analyzer which show one Embodiment of this invention. It is a simple expansion perspective view of the said cavity resonator. It is a simplified top view of the cavity resonator for demonstrating measurement operation | movement. FIG. 4 is a simplified plan view of a cavity resonator similar to that in FIG. It is a simplified top view of the same cavity resonator as FIG. 3 which shows 2nd Embodiment of this invention. FIG. 6 is a simplified plan view of a cavity resonator similar to that in FIG. It is a simplified diagram which shows the rotating plate and to-be-measured object which show 3rd Embodiment of this invention. It is a simplification figure showing the virtual division division of a device under test.

Explanation of symbols

10 Cavity Resonator 10a Insertion Port 11 Network Analyzer
22 Rotating plates A, B, M _{1 to} M ₄ , 21 DUTs P _{1 to} Pn Virtual division

Claims (10)

In a measurement method for measuring the dielectric constant of a measured object by a perturbation method by inserting the measured object into a cavity resonator that supplies microwave power,
A first step of inserting at least two or more measured objects M ₁ , M ₂ ... M _n into the cavity resonator;
Before and after the insertion of the object to be measured, the resonance angular frequencies ω _o and ω _L of the microwaves in the cavity resonator, Q _o and Q _L indicating the resonance effect, and the electric field intensity E _{1 at} each insertion position of the object to be measured, a second step of measuring the _{E 2} ····· E _n,
A third step in which the position of the object to be measured is changed according to the number of objects to be measured and the second step is repeated;
Wherein _{ω o, ω L, Q o} , Q L, E 1, E 2 ····· E n and the cavity resonator volume V, each more DUT and the volume △ V of the object each dielectric A dielectric constant measuring method using microwaves, comprising: a fourth step of calculating a rate. The measuring method according to claim 1,
The second step is a step of measuring the resonant angular frequencies ω _o , ω _L of the microwaves in the cavity resonator and Q _o , Q _L indicating the resonance effect before and after inserting the object to be measured; Electric field strengths E ₁ , E ₂ ... E _{n at} the insertion position of the object to be measured based on the longitudinal and lateral lengths a and L of the resonator, the resonance angular frequencies ω _o and ω _L , and the vacuum permeability μo. A method for measuring a dielectric constant using a microwave, characterized by comprising a calculation step of calculating In a measurement method for measuring the dielectric constant of a measured object by a perturbation method by inserting the measured object into a cavity resonator that supplies microwave power,
A first step of determining virtual division positions P ₁ , P ₂ ... P _n at least at two or more locations of the object to be measured;
Before and after the insertion of the object to be measured, the resonance angular frequencies ω _o and ω _L of the microwaves in the cavity resonator, Q _o and Q _L indicating the resonance effect, and the electric field intensity E _{1 at} each virtual division position of the object to be measured a second step of measuring the _E 2 · · · · · _{E n,}
A third step of repeating the second step by changing the position of the measurement object according to the number of division positions of the measurement object;
Wherein _{ω o, ω L, Q o} , Q L, E 1, E 2 ····· E n and the cavity resonator volume V, the virtual division more DUT and the volume △ V position of the object And a fourth step of calculating a dielectric constant at each of the divided positions. A method for measuring a dielectric constant using microwaves. In the measuring method according to claim 3,
The second step is a step of measuring the resonant angular frequencies ω _o , ω _L of the microwaves in the cavity resonator and Q _o , Q _L indicating the resonance effect before and after inserting the object to be measured; Based on the longitudinal and lateral lengths a and L of the resonator, the resonance angular frequencies ω _o and ω _L , and the vacuum magnetic permeability μo, the electric field strengths E ₁ , E _2. method of measuring the dielectric constant using a microwave characterized by comprising a calculation step of calculating an E _n. In the measurement method according to claim 1 or 3,
The second step is the resonance angular frequency omega _o at the initial measurement, omega _{L, Q} o indicating the resonance effect, _{Q L,} the electric field strength _{E 1,} by measuring the E 2 · · · · · _{E n,} initial measurement after the dielectric constant measuring method using microwaves and measuring the electric field strength _{E 1, E 2 ····· E n} . In a measuring device that measures the dielectric constant of a measured object by a perturbation method by inserting the measured object into a cavity resonator that supplies microwave power,
At least two objects to be measured inserted into the cavity resonator;
Before and after the insertion of the object to be measured, the resonance angular frequencies ω _o and ω _L of the microwaves in the cavity resonator, Q _o and Q _L indicating the resonance effect, and the electric field intensity E _{1 at} each insertion position of the object to be measured, and measurement means for measuring the _{E 2} ····· E _n,
Control means for changing the position of the object to be measured according to the number of objects to be measured and repeating the measurement by the measuring means;
Wherein _{ω o, ω L, Q o} , Q L, E 1, E 2 ····· E n and the cavity resonator volume V, each more DUT and the volume △ V of the object each dielectric An apparatus for measuring a dielectric constant using a microwave, characterized by comprising a calculation means for calculating a rate. The measuring apparatus according to claim 6, wherein
The measuring means measures the resonant angular frequencies ω _o and ω _L of microwaves in the cavity resonator before and after inserting the object to be measured, Q _o and Q _L indicating resonance effects, and the cavity Electric field strengths E ₁ , E ₂ ... E _{n at} the insertion position of the object to be measured based on the longitudinal and lateral lengths a and L of the resonator, the resonance angular frequencies ω _o and ω _L , and the vacuum permeability μo. An apparatus for measuring a dielectric constant using a microwave, characterized by comprising: a calculating means for calculating In a measuring device that measures the dielectric constant of a measured object by a perturbation method by inserting the measured object into a cavity resonator that supplies microwave power,
An object to be measured in which at least two or more virtual divided positions P ₁ , P ₂ ... P _n are determined;
Before and after the insertion of the object to be measured, the resonance angular frequencies ω _o and ω _L of the microwaves in the cavity resonator, Q _o and Q _L indicating the resonance effect, and the electric field intensity E _{1 at} each virtual division position of the object to be measured a measuring means for measuring the _E 2 _{····· E n,}
Control means for changing the position of the object to be measured according to the number of division positions of the object to be measured and repeating the measurement by the measuring means;
Wherein _{ω o, ω L, Q o} , Q L, E 1, E 2 ····· E n and the cavity resonator volume V, the virtual division more DUT and the volume △ V position of the object An apparatus for measuring a dielectric constant using a microwave, comprising: an arithmetic means for calculating a dielectric constant at each of the divided positions. The measuring apparatus according to claim 8, wherein
The measurement means measures the resonance angular frequencies ω _o and ω _L of microwaves in the cavity resonator before and after insertion of the object to be measured, Q _o and Q _L indicating resonance effects, and the cavity Based on the longitudinal and lateral lengths a and L of the resonator, the resonance angular frequencies ω _o and ω _L , and the vacuum magnetic permeability μo, the electric field strengths E ₁ , E _2. dielectric constant measuring apparatus utilizing microwaves, characterized in that comprising a calculating means for calculating a E _n. In the measuring device according to any one of claims 6 to 9,
A dielectric constant measuring apparatus using microwaves, comprising a TE _103- mode rectangular cavity resonator as the cavity resonator.

Images