JP2006311491A - Ring resonator and method of measuring dielectric characteristic of dielectric thin film using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ring resonator capable of measuring dielectric characteristics such as a specific dielectric constant and a dielectric loss tangent of a dielectric thin film, and a DC electric field strength dependence and a temperature dependence of them or the like at a microwave band and a millimeter band, particularly a frequency band of 1 GHz or over with high accuracy, and a method of measuring dielectric characteristics of a dielectric thin film using the ring resonator. <P>SOLUTION: The ring resonator is configured such that the dielectric thin film 2 is formed on a dielectric support substrate 1, and a conductor film 3 divided into an inner conductor 32 and an outer conductor 33 by an annular gap 31 is formed to the upper face of the dielectric thin film 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a ring resonator including a dielectric thin film and a method for measuring dielectric characteristics of the dielectric thin film, and in particular, relative permittivity and dielectric of a dielectric thin film in a microwave band and a millimeter wave band of 1 GHz or more. The present invention relates to a method for measuring tangents, DC electric field strength dependency, temperature dependency, and the like.

  Currently, devices using dielectric thin films are being actively developed in the microwave band and millimeter wave band, and their dielectric properties (relative permittivity and dielectric loss tangent, their DC field strength dependency, temperature dependency, etc.) Etc.) is required.

2. Description of the Related Art Conventionally, two methods are generally known as methods for measuring dielectric characteristics of a dielectric substrate in a microwave band and a millimeter wave band using a resonator method. One is a method using a three-dimensional resonator such as a cavity resonator (Non-Patent Document 1). The other is a method of using a planar resonator such as a so-called microstrip line type ring resonator configured by disposing a ring-shaped signal conductor on the upper surface of the dielectric substrate and a ground conductor on the lower surface. (Non-Patent Document 2).
JIS R 1641, established in 2002 Aly E. Fathy et al. “An Innovative Semianalytical Technique for Ceramic Evaluation at Microwave Frequencies” IEEE Trans. MTT, vol.50, pp.2247-2252, Oct. 2002.

  When the cavity resonator described in Non-Patent Document 1 used for measuring the dielectric characteristics of a dielectric substrate is applied to the dielectric characteristics measurement of a dielectric thin film, the relative dielectric constant and dielectric loss tangent of the dielectric thin film are accurately measured. Although it can be determined, since it is not possible to apply a DC voltage by installing an electrode or the like, it was not possible to measure the dependence of the relative permittivity and the dielectric loss tangent on the DC electric field strength.

  Further, when the ring resonator described in Non-Patent Document 2 is applied to the dielectric characteristic measurement of the dielectric thin film, for example, as shown in FIG. 28, the dielectric thin film 24 is formed on the dielectric support substrate 1, and this A ring resonator having a structure in which a ring-shaped signal conductor 34 is formed on the dielectric thin film 24 and a ground conductor 35 is formed on the lower surface of the dielectric support substrate 1, or a dielectric as shown in FIG. Ring resonance of a structure in which a ground conductor 35 is formed on the support substrate 1, a dielectric thin film 24 is formed on the ground conductor 35, and a ring-shaped signal conductor 34 is formed on the dielectric thin film 24. In these cases, the electric field energy is not concentrated on the dielectric thin film, or the conductor loss is large and the no-load Q is greatly deteriorated. A and dielectric loss tangent, etc. could not be determined accurately.

  The present invention has been made in view of the above circumstances, and in the microwave band and millimeter wave band, particularly in the frequency band of 1 GHz or higher, the relative permittivity and dielectric loss tangent of the dielectric thin film, and their DC electric field strength dependency, It is an object of the present invention to provide a ring resonator capable of measuring dielectric properties such as temperature dependency with high accuracy and a dielectric property measuring method for a dielectric thin film using the ring resonator.

  In the present invention, a conductor film divided into an inner conductor and an outer conductor by a ring-shaped gap and a dielectric thin film laminated on at least one of the upper surface and the lower surface of the conductor film are provided on a dielectric support substrate. It is the ring resonator characterized by the above. In such a ring resonator, a resonance mode in which an electric field is generated from one of the inner conductor and the outer conductor to the other conductor can be obtained, so that the electric field energy tends to concentrate on the dielectric thin film, and the relative permittivity And dielectric loss tangent can be determined with high accuracy. In addition, in such a ring resonator, since the above-described effect can be obtained in a plurality of modes, it is possible to measure frequency dependence with the same sample.

  Here, it is preferable that a relative dielectric constant of the dielectric thin film is higher than a relative dielectric constant of the dielectric support substrate. In such a ring resonator, in a resonance mode in which an electric field is generated from one of the inner conductor and the outer conductor toward the other, electric field energy is more likely to be concentrated on the dielectric thin film. The dielectric loss tangent and the like can be determined with higher accuracy.

  The dielectric tangent of the dielectric thin film is preferably higher than the dielectric tangent of the dielectric support substrate. In such a ring resonator, the contribution of Q of the dielectric thin film tends to be larger than the contribution of Q of the dielectric support substrate included in the unloaded Q. Therefore, the dielectric loss tangent can be determined with higher accuracy. it can.

  Furthermore, in the ring resonator of the present invention, it is preferable that the gap has a wide portion and a narrow portion. In such a ring resonator, the electric field energy is concentrated on the dielectric thin film by selectively positioning at least one of a plurality of local maximum points of the electric field strength of the resonant electromagnetic field at a narrow part of the gap. The relative permittivity, dielectric loss tangent, etc. can be determined with higher accuracy, and there is a narrow part when applying a DC voltage between the inner conductor and the outer conductor as will be described later. Thus, the applied DC voltage can be reduced. Further, since all of the plurality of local maximum points of the magnetic field strength of the resonance electromagnetic field can be positioned at a wide part of the gap, the conductor loss is further reduced, and the relative dielectric constant and The dielectric loss tangent and the like can be determined with higher accuracy, and the magnetic field can be easily excited and detected by a loop antenna or the like. In such a ring resonator, the above-described effect can be selectively obtained in a plurality of modes, so that frequency dependency measurement with the same sample can be performed with high accuracy.

  Here, it is preferable that the proportion of the wide portion in the circumferential direction is larger than the proportion of the narrow portion in the circumferential direction. Thereby, all the maximum points of the magnetic field strength of the resonance electromagnetic field can be easily located in the wide part. Note that the ratio of the wide part in the circumferential direction and the ratio of the narrow part in the circumferential direction occupy a width of a distance larger than 1/2 of the value obtained by adding the maximum value of the width and the minimum value of the width. Judgment is made based on whether the area is large or small.

  Furthermore, it is preferable that the wide portions and the narrow portions are alternately formed by 2k pieces (k: a positive integer). In such a ring resonator, one or all of a plurality of local maximum points of the electric field strength of the resonant electromagnetic field existing 2m × k (m, k: positive integers) are portions where the gap is narrow. N-th order (n = m × k) resonance mode existing in can be obtained, so that the electric field energy can be more efficiently concentrated on the dielectric thin film, and the relative permittivity, dielectric loss tangent, etc. can be made more accurate. It can be determined, and the DC voltage applied between the inner conductor and the outer conductor can be reduced. Further, in the n-th order (n = m × k) resonance mode, all of the 2m × k maximal points of the magnetic field strength can be positioned in a wide part, so that the conductor can be more efficiently conducted. The loss is reduced, the relative permittivity, the dielectric loss tangent, etc. can be determined with higher accuracy, and the magnetic field can be easily excited and detected by a loop antenna or the like.

The ring resonator of the present invention can be preferably used when the thickness of the dielectric thin film is 10 ⁻⁸ m or more and 10 ⁻⁵ m or less. Such a ring resonator is easy to manufacture and the electric field energy tends to concentrate on the dielectric thin film, so that the relative permittivity, dielectric loss tangent, etc. can be determined with high accuracy.

  In the present invention, the ring resonator is electromagnetically excited to measure a resonance frequency and no-load Q of the ring resonator, and a dielectric characteristic of the dielectric thin film is determined from the resonance frequency and the no-load Q. This is a method for measuring dielectric characteristics of a dielectric thin film. By such a dielectric property measurement method, the relative permittivity, dielectric loss tangent, etc. are determined from the resonance frequency and / or no-load Q of the resonance mode that generates an electric field from one of the inner conductor and the outer conductor to the other. It can be determined with high accuracy.

  Furthermore, the present invention provides a magnetic field excitation of the ring resonator so that a maximum point of the electric field strength of the resonance electromagnetic field exists at the narrow portion of the ring resonator, so that the resonance frequency and the resonance frequency of the ring resonator are reduced. A dielectric thin film dielectric property measuring method, comprising: measuring a load Q; and determining a dielectric characteristic of the dielectric thin film from the resonance frequency and the no-load Q. By such a dielectric property measurement method, the electric field energy is easily concentrated more efficiently on the dielectric thin film, and the relative permittivity, dielectric loss tangent, etc. can be determined with higher accuracy. Moreover, the DC voltage applied between the inner conductor and the outer conductor can be reduced.

  Still further, the present invention provides a magnetic field excitation of the ring resonator so that a maximum point of the electric field strength of the resonant electromagnetic field exists in the narrow portion of the ring resonator, and the maximum of the electric field strength in the gap. The resonance frequency and no-load Q of the n-th order (n = m × k) resonance mode in which 2m × k points (m, n: positive integer) exist are measured, and the resonance frequency and the no-load Q are A method for measuring dielectric properties of a dielectric thin film characterized by determining dielectric properties of the dielectric thin film. Such a dielectric property measurement method makes it possible to reduce the conductor loss more efficiently and to determine the relative permittivity, dielectric loss tangent, etc. with higher accuracy, and to easily excite and detect the electromagnetic field with a loop antenna or the like. can do. When m = 1, regardless of the ratio of the wide part and the narrow part of the ring-shaped gap in the circumferential direction, all the local maximum points of the electric field strength of the 2k resonance electromagnetic fields are wide. Since the n-th order resonance mode is obtained, where the maximum points of the magnetic field strength of 2k resonance electromagnetic fields are located in a wide part, which is located in a narrow part, the relative permittivity, dielectric loss tangent, etc. are the most accurate. Can be determined. Further, in such a dielectric characteristic measuring method, since the resonance waveform is not separated in resonance modes other than the nth order (n = m × k), a target resonance peak can be easily found. Further, by obtaining the m different resonance modes, it is possible to measure the frequency dependence of the same sample with higher accuracy.

  Here, it is preferable that the ring resonator is magnetically excited while applying a DC voltage between the inner conductor and the outer conductor. Thereby, the direct-current electric field strength dependence of a dielectric constant or a dielectric loss tangent can be measured.

  In the dielectric property measuring method of the present invention, the resonance frequency is preferably 1 GHz or more. In such a dielectric property measurement method, it is easy to reduce the conductor loss by using a higher-order mode, so that the dielectric loss tangent can be measured with higher accuracy.

  According to the present invention, since a resonance mode that generates an electric field from one of the inner conductor and the outer conductor toward the other conductor is obtained, electric field energy is easily concentrated on the dielectric thin film, and the relative permittivity and dielectric The tangent or the like can be determined with high accuracy.

Hereinafter, a ring resonator of the present invention and a dielectric property measuring method using the same will be described with reference to the drawings. The dielectric thin film is assumed to have a thickness of 10 ⁻⁸ m or more.

  As shown in FIGS. 1, 5, and 6, the ring resonator of the present invention includes a conductor film 3 divided into an inner conductor 32 and an outer conductor 33 by a ring-shaped gap 31, and an upper surface of the conductor film 3. The dielectric thin film 2 laminated on at least one of the lower surface and the lower surface is provided on the dielectric support substrate 1.

  The ring resonator shown in FIG. 1 has a dielectric thin film 2 formed on a dielectric support substrate 1 and is further divided into an inner conductor 32 and an outer conductor 33 by a ring-shaped gap 31 on the upper surface of the dielectric thin film 2. The conductive film 3 (a conductive film in which a so-called ring-shaped slot line is formed) is laminated.

  The dielectric support substrate 1 is a flat substrate having a length of 10 to 100 mm, a width of 10 to 100 mm, and a thickness of about 0.1 to 10 mm. The dielectric support substrate 1 is preferably made of a dielectric material having a low relative dielectric constant and a low dielectric loss tangent with respect to the dielectric thin film. In particular, sapphire, glass and the like are required because flatness is required. desirable.

  Since the dielectric thin film 2 is a measurement object for measuring dielectric characteristics in the present invention and is provided on the dielectric support substrate 1, the vertical and horizontal lengths are the same as those of the dielectric support substrate 1. The thickness is a thin film of 0.01 to 10 μm.

  The conductor film 3 is mainly made of a metal such as platinum or gold, and is divided into an inner conductor 32 and an outer conductor 33 by a ring-shaped gap 31. In other words, the conductor film 3 has a structure in which a so-called ring-shaped slot line is formed. The conductor film 2 has the same vertical and horizontal lengths, in other words, the vertical and horizontal lengths on the outer periphery of the outer conductor 33, which are formed in the same manner as the dielectric support substrate 1 in the same manner as the dielectric thin film 2, and has a thickness of 0.01. -10 μm.

  Usually, the dielectric thin film 2 and the conductor film 3 are formed on the dielectric support substrate 1 by sputtering, but a jig manufactured by machining or the like may be placed thereon.

The width of the ring-shaped gap 31 (the distance between the inner conductor 32 and the outer conductor 33) is preferably 10 ⁻⁶ to 10 ⁻² m. When this width is narrowed, the conductor loss increases, so that it is difficult to measure the dielectric loss tangent with high accuracy. Also, it becomes difficult to excite and detect the electromagnetic field of the target resonance mode. On the other hand, when this width is widened, it becomes difficult to concentrate electric field energy on the dielectric thin film, so that it is difficult to measure the relative dielectric constant with high accuracy. Moreover, it is dangerous because a large DC voltage is required to measure the DC electric field strength dependency in a certain range. In particular, the width of the ring-shaped gap 31 (the distance between the inner conductor 32 and the outer conductor 33) is preferably 10 ⁻⁵ to 10 ⁻³ m, and when the DC electric field strength dependency needs to be measured. 10 ⁻⁵ to 10 ⁻⁴ m, and 10 ⁻⁴ to 10 ⁻³ m are more desirable when it is not necessary to measure the DC electric field strength dependency.

  The shape of the ring-shaped gap 31 will be described later together with the description of the resonance mode.

  As shown in FIG. 4, such a ring resonator is excited, for example, by bringing the pair of loop antennas close to the opposing positions of the ring-shaped gap 31 in a state where the pair of loop antennas are parallel to the conductor film 3. Specifically, it is excited by a loop antenna 42 provided at the tip of one coaxial cable 41 and detected by the other loop antenna 42. More specifically, an electromagnetic field of a target resonance mode is excited by injecting a frequency-swept signal from an oscillator, for example, a synthesized sweeper, into the resonator through the loop antenna 42 from one coaxial cable 41. Then, when the transmission signal of the resonator is input from the other loop antenna 42 through the coaxial cable 41 to a measuring device such as a network analyzer, the resonance frequency and no-load Q of the ring resonator can be measured. The insertion depth of the loop antenna 42 into the ring resonator is adjusted so that the insertion loss at the resonance frequency of the resonance mode to be measured is about 30 dB.

  Here, in the above-described ring resonator, as shown in FIG. 2, since a resonance mode for generating an electric field from one of the inner conductor and the outer conductor to the other is obtained, the electric field energy is concentrated on the dielectric thin film. Therefore, the relative permittivity, the dielectric loss tangent, etc. can be determined with high accuracy. Further, in the above-described ring resonator, as shown in FIG. 3, since a resonance mode in which a magnetic field (current) is not concentrated on the conductor film 3 is obtained, the conductor loss is reduced, and the Q of the conductor included in the unloaded Q is reduced. Since the contribution of the Q of the dielectric thin film tends to increase with respect to the contribution, the dielectric loss tangent can be determined with high accuracy.

  Dielectric characteristics such as relative permittivity and dielectric loss tangent can be calculated by performing numerical analysis by a finite element method, a mode matching method or the like from the measured values of the resonance frequency of the ring resonator and the no load Q. In particular, an axially symmetric finite element method can be used for an axially symmetric ring resonator as used in the present invention, so that the resonant electromagnetic field distribution, resonant frequency can be determined from the dimensions, relative permittivity, dielectric loss tangent, etc. The no-load Q and the like can be calculated with high accuracy and in a short time. Therefore, if this is applied, the dielectric constant and dielectric loss tangent of the dielectric thin film can be obtained from the resonance frequency and the no-load Q.

More specific calculation methods include the following methods. First, the dimensions of the ring resonator are measured using a measurement microscope or the like to determine the shape. Next, the resonance frequency f ₀ when the relative dielectric constant ε ′ of the dielectric thin film 2 (dielectric sample) is changed by at least three points is calculated by an axially symmetric finite element method or the like. The calculated value of the resonance frequency f ₀ obtained at this time is preferably the measured value of the resonance frequency and the degree of variation thereof. Next, a linear approximation formula of resonance frequency f ₀ and relative permittivity ε ′, coefficients a and b of f ₀ = a × ε ′ + b are obtained by the linear least square method. Thereby, the relative dielectric constant ε ′ can be calculated from the measured value f _0A of the resonance frequency f ₀ .

Subsequently, by using the calculated value of the relative dielectric constant ε ′, the conductor Q (Q _c ) and the ratio of electric field energy accumulated in the dielectric sample (P _e ) are calculated by the axially symmetric finite element method. A relational expression of Q _u ⁻¹ = Q _c ⁻¹ + P _e × tan δ holds between the calculated values of Q _c and P _e obtained at this time, the unloaded Q (Q _u ), and the dielectric loss tangent tan δ. Therefore, the dielectric loss tangent can be calculated by substituting the measured value of no-load Q into this equation.

  Here, in order to perform measurement at a target frequency, the mode order n may be changed. When the mode order n is changed from n1 to n2, the resonance frequency becomes about n2 / n1 times. The resonance frequency can also be controlled by changing the shape of the ring resonator (ring diameter d, gap width w, etc.). When the ring diameter d is changed from d1 to d2, the resonance frequency becomes about d1 / d2. Moreover, since the electric field energy concentrates on the dielectric thin film when the gap width w is reduced, the resonance frequency is lowered, and when the gap width w is increased, the electric field energy does not concentrate on the dielectric thin film. The resonance frequency is increased.

  In the dielectric property measurement method of the present invention, it is necessary to measure in advance the dielectric properties (dielectric constant, dielectric loss tangent) of the dielectric support substrate and the conductivity of the conductor film. The dielectric constant of the dielectric support substrate can be measured by using a conventional cavity resonator method or the like. For the conductivity of the conductor film, for example, a ring resonator having a structure in which the dielectric thin film 2 and the dielectric thin film 4 in the ring resonator of the present invention shown in FIGS. 1, 5, and 6 are removed is used. Can be measured by.

  In the ring resonator shown in FIG. 1, the inner conductor 32 and the outer conductor 33 are exposed, and a DC voltage can be easily applied between them. For example, as shown in FIG. 4, the terminal 5 is joined on the inner conductor 32 and the outer conductor 33, and the terminal 7 and the DC power source are electrically connected via a conducting wire or the like to apply a DC voltage. Is done. As a method for forming the terminal 5 at this time, any method may be used as long as it is formed at a temperature not affecting the dielectric thin film 2, the conductor film 3, and the like. Examples thereof include plating, vapor deposition, printing, etching, reflow, or a combination of these. The terminal 5 may be made of any material such as gold, silver, copper, and solder, but gold, silver, copper, and the like are preferable from the viewpoint of low electrical resistance, and solder is preferable from the viewpoint of a low melting point.

  When the ring resonator is magnetically excited along with the application of the DC voltage, the relative permittivity and the dielectric loss tangent dependency of the DC electric field strength can be measured. This measuring method will be described later.

  In addition, from the viewpoint of reducing the contribution of the radiation Q included in the unloaded Q, a shielding conductor that can cover the entire ring resonator, a temperature chamber, etc. from the point of measuring the temperature dependence of the dielectric constant May be installed.

  In the present invention, a dielectric thin film 2 is formed on a dielectric support substrate 1 as shown in FIG. 1, and an inner conductor 32 and an outer conductor 33 are formed on the upper surface of the dielectric thin film 2 by a ring-shaped gap 31. The structure is not limited to the structure in which the conductor films 3 divided into two are stacked, and the structure shown in FIGS. 5 and 6 can also be adopted.

  In the ring resonator shown in FIG. 5, a conductor film 3 divided into an inner conductor 32 and an outer conductor 33 by a ring-shaped gap 31 is provided on a dielectric support substrate 1, and a dielectric film is formed on the upper surface of the conductor film 3. The body thin film 2 is laminated. Further, in the drawing, a part of the dielectric thin film 2 (upper side of the inner conductor 32 and upper side of the outer conductor 33) is provided so that a DC voltage can be applied between the inner conductor 32 and the outer conductor 33 of the conductor film 3. A pair of DC voltage application holes 6 are provided, and a part of the inner conductor 32 and a part of the outer conductor 33 are exposed.

  In the ring resonator shown in FIG. 6, the conductor film 3 divided into the inner conductor 32 and the outer conductor 33 by the ring-shaped gap 31 on the dielectric support substrate 1, and the upper and lower surfaces of the conductor film 3 The laminated dielectric thin film 2 is provided. Further, in the drawing, a part of the dielectric thin film 2 (upper side of the inner conductor 32 and upper side of the outer conductor 33) is provided so that a DC voltage can be applied between the inner conductor 32 and the outer conductor 33 of the conductor film 3. A pair of DC voltage application holes 6 are provided, and a part of the inner conductor 32 and a part of the outer conductor 33 are exposed.

Next, the shape of the ring-shaped gap 31 and the resonance mode will be described.
FIG. 7 is a plan view for explaining the shape and resonance mode (primary resonance mode) of the ring-shaped gap 31 of the ring resonator of the present invention, and the width of the ring-shaped gap does not change in one round, A primary resonance mode in which one wavelength of the resonance electromagnetic field exists in one circle is shown.

  As shown in FIG. 7, when the width of the ring-shaped gap does not change in one round (not having a wide part and a narrow part), an axially symmetric finite element method can be used. Resonance electromagnetic field distribution, resonance frequency, no load Q, etc. can be calculated with high accuracy and in a short time from dielectric constant, dielectric loss tangent and the like. However, in this case, it is difficult to achieve both the measurement of the DC electric field strength dependence in a certain range without requiring a large DC voltage and the excitation and detection of the electromagnetic field of the target resonance mode.

  Therefore, the width of the ring-shaped gap in the former is desirably narrowed at at least one point (field maximum point) at which the electric field strength of the resonant electromagnetic field is maximized, and the width of the ring-shaped gap in the latter is It is desirable that at least two points (one for excitation and one for detection) at which the magnetic field strength of the resonance electromagnetic field is maximized are widened. Further, in order to concentrate electric field energy on the dielectric thin film and to measure the relative permittivity, dielectric loss tangent, etc. with high accuracy, the width of the ring-shaped gap should be narrow at at least one of the electric field maximum points. desirable. In other words, it is desirable that the ring-shaped gap has a wide portion and a narrow portion. Further, in order to reduce the conductor loss and to measure the relative dielectric constant and the dielectric loss tangent with high accuracy, it is desirable that the width of the ring-shaped gap is wide at all the magnetic field maximum points. In other words, it is desirable that the proportion of the wide portion in the circumferential direction in the ring-shaped gap is larger than the proportion of the narrow portion in the circumferential direction. Examples of such shapes and resonance modes are shown in FIGS.

  FIG. 8 is a plan view for explaining another shape of the ring-shaped gap and the resonance mode, in which (a) represents the primary resonance mode and (b) represents the secondary resonance mode. And the ring-shaped gap has a change in one round. In other words, there are two narrow parts and two wide parts, and the ratio of the wide part in the circumferential direction is a narrow part. It is larger than the ratio in the circumferential direction. Note that the ratio of the wide part in the circumferential direction and the ratio of the narrow part in the circumferential direction occupy a width of a distance larger than 1/2 of the value obtained by adding the maximum value of the width and the minimum value of the width. Judgment is made based on whether the area is large or small.

  In the case where the ring-shaped gap has the shape shown in FIG. 8, there is a possibility that both the above requirements at the electric field maximum point and the magnetic field maximum point are made compatible. There may be a primary resonance mode in which one wavelength exists in one circle as shown in FIG. 8A and a secondary resonance mode in which two wavelengths exist in one circle as shown in FIG. 8B. The structure of the ring-shaped gap has a symmetry of 180 deg, and there can exist a resonance mode as shown in FIG. 8 and a resonance mode in which the electric field maximum point and the magnetic field maximum point are inverted (the principle of minimum action). ). Therefore, when the resonance mode as shown in FIG. 8 is used, the narrowest point in the ring gap has half or all of the electric field maximum points, and the widest width (FIG. 8A) or relatively The measurement can be performed using a resonance mode in which all of the magnetic field maximum points are present at a wide point (FIG. 8B). From this meaning, it can be seen that the ring-shaped gap may have at least two kinds of widths.

  FIG. 9 is a plan view for explaining still another shape of the ring-shaped gap and the resonance mode, where (a) represents the primary resonance mode and (b) represents the secondary resonance mode. In the ring-shaped gap, there are one narrow part and one wide part, and the ratio of the wide part in the circumferential direction is larger than the ratio of the narrow part in the circumferential direction. Yes.

  When the ring-shaped gap has the shape shown in FIG. 9, a primary resonance mode in which one wavelength exists in one turn as shown in FIG. 9A, or two wavelengths exist in one turn as shown in FIG. 9B. The following resonance modes can exist. There may also be a resonance mode in which the electric field maximum point and the magnetic field maximum point are reversed (the principle of minimum action). Therefore, as shown in FIG. 9, the measurement can be performed using a resonance mode in which one of the electric field maximum points is in a narrow portion and all the magnetic field maximum points are in a wide portion. As described above, in order to locate all the magnetic field maximum points in the wide portion even in the higher-order mode, it is desirable that the wide portion occupies a larger ratio in the circumferential direction than the narrow portion. This ratio can be appropriately adjusted in consideration of the order of the mode to be measured. In the shape of the ring-shaped gap as shown in FIG. 9, it is preferable that the narrow portion is less than 90 / m [deg] when measuring up to the n-th order (n wavelength per round) resonance mode.

  Further, in FIG. 9, assuming that the wide portion of the ring-shaped gap and the narrow portion are alternately formed by 2k pieces (k: positive integer), the k-th order resonance mode is expressed as follows. When used, it is considered that all of the electric field maximum points are in a narrow portion.

  Therefore, it is desirable that the wide portions and the narrow portions are alternately formed by 2k pieces (n: a positive integer). An example of such shape and resonance mode is shown in FIG.

  FIG. 10 is a plan view for explaining still another shape of the ring-shaped gap and the resonance mode, where (a) is m × k = second order resonance mode, and (b) is m × k = fourth order. Resonance mode is represented. In the ring-shaped gap, four wide portions and narrow portions are alternately formed (in the case of 2k k = 2).

  Then, when the ring-shaped gap has a periodic structure in which 2k wide portions and narrow portions are alternately formed (k: positive integer) as shown in FIG. 10, the maximum point of electric field strength is 2m × k (m, k: positive integer) n-order (n = m × k) resonance modes, for example, a second-order resonance mode or a diagram having two wavelengths in one circle as shown in FIG. There may be a fourth-order resonance mode such as 10 (b) in which four wavelengths exist in one round. There may also be a resonance mode in which the electric field maximum point and the magnetic field maximum point are reversed (the principle of minimum action). Therefore, as shown in FIG. 10, measurement can be performed using a resonance mode in which half or all of the electric field maximum points are present in a narrow portion and all the magnetic field maximum points are present in a wide portion.

  FIG. 11 is a plan view (top) and a cross-sectional view (bottom) for explaining still another structure of the ring resonator of the present invention.

The ring resonator shown in FIG. 11 has a ring-shaped gap in which a wide portion and a narrow portion are alternately formed, and the wide portion and the narrow portion are 20 (2k pieces) in one round. (When k = 10), each has a periodic structure. As described above, in such a ring resonator, some or all of the maximum points of a plurality of electric field strengths that are 20 m (2 m × k k = 1, where m is a positive integer) have a width. A resonance mode of 10 m order (having a wavelength of 10 m per round) located in a narrow part is obtained. If such a resonance mode is used, it becomes easy to obtain a resonance mode of the 10th order (having a wavelength of 10 m per round) in which all of the maximum points of a plurality of magnetic field strengths existing in 20 m are located in a wide portion. The conductor loss is reduced, and the dielectric loss tangent can be easily measured with high accuracy. In addition, it is easy to excite and detect the electromagnetic field of the target resonance mode. In addition, since the electric field energy is concentrated on the dielectric thin film 2, the relative permittivity can be measured with high accuracy. In addition, it is safe because a large DC voltage is not required in measuring the DC field strength dependency in a certain range. In particular, the distance w5 between the inner conductor 32 and the outer conductor 33 in the narrow part is preferably 10 ⁻⁷ to 10 ⁻⁴ m, and the distance w4 between the inner conductor 32 and the outer conductor 33 in the wide part is It is desirable that it is 10 ^{< -5} > -10 ^<-2> m. Further, the ratio of the wide portion and the narrow portion in the circumferential direction is preferably 2: 1 to 200: 1. If this ratio is less than 2: 1, the above effect is difficult to obtain, and if it is greater than 200: 1, it is difficult to identify the target resonance mode. In addition, numerical calculation becomes difficult.

As a method of measuring the dependency of the dielectric thin film on the DC electric field strength using the ring resonator shown in FIG.
First, a resonance mode in the case where a DC voltage is not applied between the inner conductor 32 and the outer conductor 33 (a part or all of the maximum points of the electric field strength existing in 20 m are located in a narrow part in the ring-shaped gap. ) And the dielectric characteristics such as dielectric constant and dielectric loss tangent are calculated in advance from the measured values of the resonance frequency and no-load Q. Next, the resonance frequency and no-load Q in the resonance mode when a DC voltage is applied between the inner conductor 32 and the outer conductor 33 are measured, and the relative dielectric constant of the dielectric thin film located in the narrow portion is calculated. These dielectric characteristics are calculated on the assumption that only the dielectric loss tangent or the like changes. At this time, the relative dielectric constant, dielectric loss tangent, and the like of the dielectric thin film located in the wide portion are assumed to be equal to the calculation result when no DC voltage is applied. By measuring changes in the resonance frequency and no-load Q in each resonance mode when this DC voltage is changed as appropriate, the dependence of the dielectric thin film on the target frequency, such as relative permittivity and dielectric loss tangent, at the target frequency can be determined. Can be calculated. Specifically, the effective DC electric field intensity E _eff generated in the dielectric thin film located in the narrow portion is determined from the DC voltage V and the distance L between the inner conductor 32 and the outer conductor 33 in the narrow portion as follows. By determining (Equation 1), the direct current electric field strength dependency such as the relative dielectric constant and dielectric loss tangent of the dielectric thin film at the target frequency can be calculated.

However, in the above method, the distance between the inner conductor 32 and the outer conductor 33 in the wide part is sufficiently larger than the distance between the inner conductor 32 and the outer conductor 33 in the narrow part, and the narrow part in the narrow part. It is effective when the distance between the inner conductor 32 and the outer conductor 33 is sufficiently large with respect to the thickness of the inner conductor 32 and the outer conductor 33. In other cases, the dielectric is located in a narrow portion. It is impossible to assume that only the relative dielectric constant or dielectric loss tangent of the thin film changes, or the effective DC electric field strength E _eff generated in the dielectric thin film located in a narrow portion can be determined by (Equation 1). Because it disappears, it is not effective.

Therefore, ideally, a DC electric field intensity (E ₁ ) distribution when a DC voltage is applied between the inner conductor 32 and the outer conductor 33 and an electric field intensity (E ₂ ) distribution at the resonance frequency of the resonance mode are obtained. By calculating, the dependence of the dielectric thin film on the DC electric field strength such as the relative permittivity and the dielectric loss tangent is calculated. Specifically, a variation Delta] f _{0, i} of the resonance frequency due to variation [Delta] [epsilon] _'i of the dielectric constant at each micro area i of the dielectric thin film, the amount of change ΔQ of the unloaded Q by variation Derutatieienuderuta _i of dielectric loss tangent _{u, i} is the magnitude of the electric field energy ratio _{Pe, i} in each minute region i of the dielectric thin film at the resonance frequency of the resonance mode expressed by the following (Equation 2). Using the proportional increase, the effective DC electric field intensity E _eff generated in the dielectric thin film is calculated from the weighted average of the DC electric field intensity E _{1, i} when the DC voltage is applied by the above P _{e, i.} It can be determined as in (Equation 3) below.

  Accordingly, regardless of the distance between the inner conductor 32 and the outer conductor 33 in the wide portion, the distance between the inner conductor 32 and the outer conductor 33 in the narrow portion, the thickness of the inner conductor 32 and the outer conductor 33, and the like. It is possible to accurately calculate the DC voltage dependency such as the dielectric constant and dielectric loss tangent of the dielectric thin film.

When measuring the DC electric field strength dependence of a dielectric thin film using the axially symmetric ring resonator shown in FIGS. 1, 5, and 6, the gap between the inner conductor 32 and the outer conductor 33 is measured. The DC electric field intensity (E ₁ ) when a DC voltage is applied can be considered uniform in the circumferential direction, and the distribution of the electric field intensity (E ₂ ) at the resonance frequency of the resonance mode with respect to the radial direction is the radial direction of E ₁ . Therefore, it is not necessary to calculate the distribution of E ₂ , and it is only necessary to calculate the distribution of E ₁ . At this time, the effective DC electric field intensity E _eff generated in the dielectric thin film can be determined by (Equation 2).

  According to the above-described method in which the dependence of the dielectric thin film on the direct current electric field strength such as the relative permittivity and the dielectric loss tangent is known, the effect can be exerted when the dielectric thin film is applied to, for example, a variable capacitor (tunable capacitor). it can.

  Although the embodiments of the present invention have been described above, the embodiments of the present invention are not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention.

The ring resonator model of the present invention shown in FIG. 1 (dielectric support substrate thickness a1 = 0.3 mm, dielectric thin film thickness b1 = 0.001 mm, conductor film thickness c1 = 0.001 mm, ring diameter d1 = 20 mm , The width w1 of the ring-shaped gap was 0.05 mm), and numerical analysis was performed by the axially symmetric finite element method. At this time, the dielectric constant of the dielectric support substrate was assumed to be sapphire, and the relative permittivity ε ′ = 11.54 and Qf = 10 ⁶ GHz. Moreover, the electrical conductivity of the conductor film was assumed to be Pt, and the electrical conductivity was σ = 9.434 × 10 ⁶ S / m.

First, when the dielectric constant of the dielectric thin film is the relative dielectric constant ε ′ = 500 and the dielectric loss tangent tan δ = 0.05, the resonance frequency f ₀ and the Q value (conductor Q: Q _c , dielectric support substrate Q: Q _{d, sub} , dielectric thin film Q: Q _{d, film} , unloaded Q: Q _u ) were calculated.

FIG. 12 shows the calculation result of the resonance frequency f ₀ with respect to the mode order n. It can be seen that the mode order n and the resonance frequency f ₀ are in a substantially proportional relationship. This indicates that measurement at a higher frequency is possible by using a higher-order mode.

FIG. 13 shows the calculation result of the Q value for the mode order n. As the mode order increases, it can be seen that Q _c is high. This indicates that the magnetic field (current) is not concentrated on the conductor film by using the higher-order mode. Further, it can be seen that _{Qd, sub} decreases as the mode order increases. Since the concentration ratio of the electric field energy on the dielectric support substrate and the concentration ratio of the electric field energy on the dielectric thin film hardly change depending on the mode order, this change is caused by the increase in tan δ of sapphire accompanying the increase in frequency. It can be said.

Next, when the mode order n is n = 10, the resonance frequency f ₀ and the Q value (the conductor Q: Q _c , the dielectric support substrate Q: Q _{d, sub} , the dielectric thin film Q: Q _{d, film} , no load Q: Q _u ).

FIG. 14 shows the calculation result of the resonance frequency f ₀ with respect to the relative dielectric constant ε ′ of the dielectric thin film. It can be seen that the change in f ₀ with respect to the change in ε ′ has a sufficiently large slope. Assuming actual measurement, since the measurement error of f ₀ is usually about ± 1 MHz, it can be seen from the measured value of f ₀ that ε ′ can be determined with high accuracy by using the chart of FIG.

FIG. 15 shows the calculation result of the Q value with respect to the dielectric loss tangent tan δ of the dielectric thin film. change of Q _u for tanδ change of it can be seen that have a sufficiently large slope. Assuming the actual measurement, since a measurement error of Q _u is usually about ± 5%, than the measured value of Q _u, by using the chart of FIG. 15, it can be seen that determining the tanδ at high accuracy.

The ring resonator model of the present invention shown in FIG. 5 (dielectric support substrate thickness a2 = 0.3 mm, dielectric thin film thickness b2 = 0.001 mm, conductor film thickness c2 = 0.001 mm, ring diameter d2 = 20 mm , The width w2 of the ring-shaped gap was 0.05 mm), and numerical analysis was performed by the axially symmetric finite element method. At this time, the dielectric constant of the dielectric support substrate was assumed to be sapphire, and the relative permittivity ε ′ = 11.54 and Qf = 10 ⁶ GHz. Moreover, the electrical conductivity of the conductor film was assumed to be Pt, and the electrical conductivity was σ = 9.434 × 10 ⁶ S / m.

Resonant frequency f ₀ and Q value when mode order n is n = 10 (conductor Q: Q _c , dielectric support substrate Q: Q _{d, sub} , dielectric thin film Q: Q _{d, film} , none The load Q: Q _u ) was calculated.

FIG. 16 shows the calculation result of the resonance frequency f ₀ with respect to the relative dielectric constant ε ′ of the dielectric thin film. It can be seen that the change in f ₀ with respect to the change in ε ′ has a sufficiently large slope. Assuming actual measurement, the measurement error of f ₀ is normally about ± 1 MHz, so it can be seen from the measurement value of f ₀ that ε ′ can be determined with high accuracy by using the chart of FIG.

FIG. 17 shows the calculation result of the Q value with respect to the dielectric loss tangent tan δ of the dielectric thin film. change of Q _u for tanδ change of it can be seen that have a sufficiently large slope. Assuming the actual measurement, since a measurement error of Q _u is usually about ± 5%, than the measured value of Q _u, by using the chart of FIG. 17, it can be seen that determining the tanδ at high accuracy.

The ring resonator model of the present invention shown in FIG. 6 (dielectric support substrate thickness a3 = 0.3 mm, dielectric thin film thickness b3 = 0.001 mm, conductor film thickness c3 = 0.001 mm, ring diameter d4 = 20 mm , A ring-shaped gap width w3 = 0.05 mm) was prepared, and numerical analysis was performed by an axially symmetric finite element method. At this time, the dielectric constant of the dielectric support substrate was assumed to be sapphire, and the relative permittivity ε ′ = 11.54 and Qf = 10 ⁶ GHz. Moreover, the electrical conductivity of the conductor film was assumed to be Pt, and the electrical conductivity was σ = 9.434 × 10 ⁶ S / m.

Resonant frequency f ₀ and Q value when mode order n is n = 10 (conductor Q: Q _c , dielectric support substrate Q: Q _{d, sub} , dielectric thin film Q: Q _{d, film} , none The load Q: Q _u ) was calculated.

FIG. 18 shows a calculation result of the resonance frequency f ₀ with respect to the relative dielectric constant ε ′ of the dielectric thin film. It can be seen that the change in f ₀ with respect to the change in ε ′ has a sufficiently large slope. Assuming actual measurement, since the measurement error of f ₀ is usually about ± 1 MHz, it can be seen from the measured value of f ₀ that ε ′ can be determined with high accuracy by using the chart of FIG.

FIG. 19 shows the calculation result of the Q value with respect to the dielectric loss tangent tan δ of the dielectric thin film. change of Q _u for tanδ change of it can be seen that have a sufficiently large slope. Assuming the actual measurement, since a measurement error of Q _u is usually about ± 5%, than the measured value of Q _u, by using the chart of FIG. 19, it can be seen that determining the tanδ at high accuracy.

  The ring resonator model of the present invention shown in FIG. 1 (dielectric support substrate thickness a1 = 0.3 mm, dielectric thin film thickness b1 = 0.001 mm, conductor film thickness c1 = 0.001 mm, ring diameter d1 = 20 mm The width of the ring-shaped gap w1 = 0.5 mm) was prepared, and numerical analysis was performed by an axially symmetric finite element method. Except that the width of the ring-shaped gap is changed, the calculation is exactly the same as in <Example 1>.

FIG. 20 shows the calculation result of the resonance frequency f ₀ with respect to the mode order n when the dielectric constant of the dielectric thin film is set to the relative dielectric constant ε ′ = 500 and the dielectric loss tangent tan δ = 0.05. By having an increased width w1 of the ring-shaped gap, it can be seen that f ₀ is higher. This can be attributed to the fact that the electric field energy is no longer concentrated on the dielectric thin film.

FIG. 21 shows the calculation result of the Q value for the mode order n at this time. By having an increased width w1 of the ring-shaped gap, it can be seen that Q _c is high. This indicates that the magnetic field (current) is not concentrated on the conductor film. It can also be seen that Q _{d, sub} is lowered by increasing w1. This can be attributed to the fact that the electric field energy is concentrated on the dielectric supporting substrate as the electric field energy is not concentrated on the dielectric thin film.

Next, when the mode order n is n = 10, the resonance frequency f ₀ and the Q value (the conductor Q: Q _c , the dielectric support substrate Q: Q _{d, sub} , the dielectric thin film Q: Q _{d, film} , no load Q: Q _u ).

FIG. 22 shows the calculation result of the resonance frequency f ₀ with respect to the relative dielectric constant ε ′ of the dielectric thin film when the mode order n is n = 10. <Embodiment 1> It can be seen that the change in f ₀ with respect to the change in ε ′ has a sufficiently large slope, though not so much. Assuming actual measurement, since the measurement error of f ₀ is usually about ± 1 MHz, it can be seen from the measured value of f ₀ that ε ′ can be determined with high accuracy by using the chart of FIG.

FIG. 23 shows the calculation result of the Q value with respect to the dielectric loss tangent tan δ of the dielectric thin film. Compared to <Example 1>, Q _{d and film} are high because electric field energy is not concentrated on the dielectric thin _film . However, since Q _c is higher than that, the change of Q _u is < It can be seen that the slope is sufficiently larger than in the case of Example 1>. Assuming the actual measurement, since a measurement error of Q _u is usually about ± 5%, than the measured value of Q _u, by using the chart of FIG. 23, it can be seen that determining the tanδ at high accuracy. In particular, when it is not necessary to measure the DC electric field strength dependency, it is considered that the width w1 of the ring-shaped gap is more appropriate than that of <Example 1>.

The ring resonator model of the present invention shown in FIG. 21 (dielectric support substrate thickness a4 = 0.3 mm, dielectric thin film thickness b4 = 0.001 mm, conductor film thickness c4 = 0.001 mm, ring diameter d4 = 10 mm Width of wide ring-shaped gap w4 = 0.1 mm, width of narrow ring-shaped gap w5 = 0.01 mm, angle of wide ring-shaped gap = 12 °, angle of narrow ring-shaped gap = 6) and a calculation model shown in FIG. 22 was produced. In this calculation model, in consideration of symmetry, only the thick frame portion in FIG. 21 is cut out (the radial width e of the dielectric support substrate is 0.5 mm, and the radial width f of the conductor film is 0.2 mm). , Dielectric support substrate thickness g = 0.2 mm, upper air layer thickness h = 0.2 mm). As for boundary conditions to be given when cutting, both end faces in the circumferential direction are made of electric walls (all of the 20 electric field maximum points existing in the 10th-order resonance mode are connected to the inner conductor 3 with the narrower width of the ring-shaped gap). All of the 20 magnetic field maximum points that are located between the outer conductor 4 and the outer conductor 4 are located between the wider inner conductor 3 and the outer conductor 4 of the ring-shaped gap. A magnetic wall was used. Using this calculation model, numerical analysis was performed by a three-dimensional finite element method (commercial software: HFSS). At this time, the relative permittivity of the dielectric support substrate is assumed to be sapphire, and the relative permittivity in the direction perpendicular to the c-axis (direction perpendicular to the plane where the ring-shaped gap exists) is ε _⊥ = 9.4, c-axis The relative dielectric constant in the direction parallel to (direction parallel to the plane in which the ring-shaped gap exists) was set to ε _// = 11.54. Since the dielectric loss tangent of the dielectric support substrate is much smaller than the dielectric loss tangent of the dielectric thin film, it was ignored as tan δ = 0. Moreover, the electrical conductivity of the conductor film was assumed to be Pt, and the electrical conductivity was σ = 9.434 × 10 ⁶ S / m.

First, when the dielectric constant of the dielectric thin film is the relative dielectric constant ε ′ = 500 and the dielectric loss tangent tan δ = 0.05, the resonance frequency f ₀ and the Q value of the mode order n = 10 (Q of the conductor: Q _c , dielectric The body thin film Q: _{Qd, film} , no load Q: _Qu ) was calculated.

As a result of calculation, f ₀ = 16.600 GHz, Q _c = 60.6, Q _{d, film} = 27.1, and Q _u = 18.7. FIG. 23 and FIG. 24 show the electric field distribution and magnetic field distribution of this resonance mode, respectively. The field maximum point is located between the inner conductor and the outer conductor having the smaller width of the ring gap, and the field maximum point is located between the inner conductor and the outer conductor having the larger width of the ring gap. You can see that

As a result of performing the same calculation as in the above model, when only the wide ring gap width w4 = 0.1 mm exists, f ₀ = 31.492 GHz, Q _c = 89.0, Q _{d, film} = 49.9, Q _u = 32.0, if only narrow ring gap width w5 = 0.01 mm exists, f ₀ = 19.701 GHz, Q _c = 21.6, Q _{d, film} = 25.6, Q _u = 11.7, both end surfaces in the circumferential direction are magnetic walls (all of the 20 electric field maximum points existing in the 10th-order resonance mode are the inner conductor 3 and the outer side of the wider ring-shaped gap) When all of the 20 magnetic field maximum points existing between the conductor 4 and the conductor 4 are located between the inner conductor 3 and the outer conductor 4 having a smaller width of the ring-shaped gap, f ₀ = 34 .325 GHz, Q _c = 42.0, Q _{d, film} = 42.8, Q _u = 21.2. Thus, the calculation model shown in FIG. 22, wider if only the width of the ring-shaped gap exists as well as the conductor loss is small (high Q _c is), only the width of the narrower of the ring-shaped gap exists In the same manner as described above, electric field energy is concentrated on the dielectric thin film ( _{Qd and film} are low).

Next, the resonance frequency f ₀ of mode order n = 20 and Q: Q _{d, film} of the dielectric thin _film were calculated.

As a result of calculation, f ₀ = 47.463 GHz, Q _{d, film} = 49.7. In the above mode, both end faces in the circumferential direction are provided between the inner conductor 3 and the outer conductor 4 with the magnetic walls (half of the electric field maximum points existing in the 20th-order resonance mode being narrower in the ring-shaped gap). And all of the 40 magnetic field maximal points are located between the inner conductor 3 and the outer conductor 4 having the larger width of the ring-shaped gap).

Next, assuming a case where a DC voltage is applied to the inner conductor 3 and the outer conductor 4, only the relative dielectric constant of the dielectric thin film between the inner conductor 3 and the outer conductor 4 with the narrower ring-shaped gap is selected. Is a resonance frequency of mode order n = 10 when ε ′ = 500 is changed from ε ′ = 500 to ε ′ = 50 (the electric field strength between the inner conductor 3 and the outer conductor 4 with the narrower width of the ring gap increases) the calculation was performed of f _0.

FIG. 25 shows a calculation result of the resonance frequency f ₀ with respect to the relative dielectric constant ε ′ of the dielectric thin film between the inner conductor and the outer conductor having the narrower ring-shaped gap. It can be seen that the change in f ₀ with respect to the change in ε ′ has a sufficiently large slope. Assuming actual measurement, the measurement error of f ₀ is usually about ± 1 MHz, and it can be seen from the measurement value of f ₀ that ε ′ can be determined with high accuracy by using the chart of FIG.

The ring resonator model of the present invention shown in FIG. 1 (dielectric support substrate thickness a1 = 0.3 mm, dielectric thin film thickness b1 = 0.001 mm, conductor film thickness c1 = 0.001 mm, ring diameter d1 = arbitrary Assuming calculation of DC electric field strength dependency such as relative permittivity and dielectric loss tangent of the dielectric thin film in the width w1 of the ring-shaped gap (0.1 mm), numerical analysis was performed by a two-dimensional finite element method. Using the results of the DC electric field strength E _i in each minute area i of the dielectric thin film obtained at this time was calculated effective DC electric field strength E _eff generated in the dielectric thin film (Formula 2). At this time, it was assumed that the dielectric thin film had a relative dielectric constant ε ′ = 500 and the dielectric constant of the dielectric support substrate was sapphire, and the relative dielectric constant ε ′ = 9.4. The DC voltage applied between the inner conductor and the outer conductor was 100V.

As a result of the calculation, E _eff = 1.03 × 10 ⁶ V / m. This approximates the result (E _eff = 1.00 × 10 ⁶ V / m) according to (Equation 3) when a uniform DC electric field is considered. That is, when the width w1 of the ring-shaped gap is 0.1 mm, the result by (Expression 2) and the result by (Expression 3) are approximated.

Next, the effective DC electric field strength E _eff generated in the dielectric thin film when the width w1 of the ring-shaped gap was changed from w1 = 0.1 mm to w1 = 0.015 mm was calculated.

As a result of the calculation, E _eff = 6.20 × 10 ⁷ V / m. This is a small value with respect to the result (E _eff = 6.67 × 10 ⁷ V / m) based on (Equation 3) when a uniform DC electric field is considered. That is, when the width w1 of the ring-shaped gap is 0.0015 mm, the result by (Expression 2) and the result by (Expression 3) are greatly different.

  Therefore, it is understood that it is preferable to calculate using (Equation 2).

It is the top view (upper) and sectional drawing (lower) for demonstrating the ring resonator of this invention. FIG. 2 is a shading diagram showing an electric field distribution in a cross section of a ring-shaped gap in the ring resonator shown in FIG. 1. FIG. 2 is a shading diagram showing a magnetic field distribution in a cross section of a ring-shaped gap in the ring resonator shown in FIG. 1. It is the top view (upper) and sectional drawing (lower) for demonstrating the dielectric property measuring method of this invention. It is the top view (upper) and sectional drawing (lower) for demonstrating the other structure of the ring resonator of this invention. It is the top view (upper) and sectional drawing (lower) for demonstrating other structure of the ring resonator of this invention. It is a top view for demonstrating the shape of the ring-shaped gap | interval and resonance mode (n = 1) of the ring resonator of this invention. It is a top view for demonstrating the other shape and resonance mode of the ring-shaped gap | interval of the ring resonator of this invention, (a) represents the primary resonance mode, (b) represents the secondary resonance mode. It is a top view for demonstrating other shape and resonance mode of the ring-shaped gap | interval of the ring resonator of this invention, (a) represents the primary resonance mode, (b) represents the secondary resonance mode. . It is a top view for demonstrating still another shape and resonance mode of the ring-shaped gap | interval of the ring resonator of this invention, (a) is m * k = secondary resonance mode, (b) is m * k. = Represents the fourth-order resonance mode. FIG. 6 is a plan view (upper) and a cross-sectional view (lower) for explaining still another structure of the ring resonator of the present invention. 6 is a graph showing a calculation result of a resonance frequency f ₀ with respect to a mode order n in the ring resonator model of FIG. 1. 6 is a graph showing a calculation result of a Q value with respect to a mode order n in the ring resonator model of FIG. 1. 6 is a graph showing a calculation result of a resonance frequency f ₀ with respect to a relative dielectric constant ε ′ of a dielectric thin film in the ring resonator model of FIG. 3 is a graph showing a calculation result of a Q value with respect to a dielectric loss tangent tan δ of a dielectric thin film in the ring resonator model of FIG. 1. 6 is a graph showing a calculation result of a resonance frequency f ₀ with respect to a relative dielectric constant ε ′ of a dielectric thin film in the ring resonator model of FIG. 5. 6 is a graph showing a calculation result of a Q value with respect to a dielectric loss tangent tan δ of a dielectric thin film in the ring resonator model of FIG. 5. FIG. 7 is a graph showing a calculation result of a resonance frequency f ₀ with respect to a relative dielectric constant ε ′ of a dielectric thin film in the ring resonator model of FIG. 6. It is a graph showing the calculation result of Q value with respect to the dielectric loss tangent tan-delta of the dielectric thin film in the ring resonator model of FIG. 6 is a graph showing a calculation result of a resonance frequency f ₀ with respect to a mode order n in the ring resonator model of FIG. 1. 6 is a graph showing a calculation result of a Q value with respect to a mode order n in the ring resonator model of FIG. 1. 6 is a graph showing a calculation result of a resonance frequency f ₀ with respect to a relative dielectric constant ε ′ of a dielectric thin film in the ring resonator model of FIG. 3 is a graph showing a calculation result of a Q value with respect to a dielectric loss tangent tan δ of a dielectric thin film in the ring resonator model of FIG. 1. It is a figure for demonstrating the calculation model in the ring resonator model of FIG. FIG. 12 is a shading diagram showing the electric field distribution on the upper surface portion of the dielectric thin film in the ring resonator model of FIG. 11. FIG. 12 is a shading diagram showing a magnetic field distribution on the upper surface portion of the dielectric thin film in the ring resonator model of FIG. 11. 12 is a graph showing a calculation result of a resonance frequency f ₀ with respect to a relative dielectric constant of a dielectric thin film in a portion having a narrow width of a ring-shaped gap in the ring resonator model of FIG. It is the top view (upper) and sectional drawing (lower) for demonstrating the comparative example of a ring resonator. It is the top view (upper) and sectional drawing (lower) for demonstrating the other comparative example of a ring resonator.

Explanation of symbols

1: Dielectric support substrate 2: Dielectric thin film (sample)
3: Conductor film 31: Gap 32: Inner conductor 33: Outer conductor 41: Coaxial cable 42: Loop antenna 5: Terminal 6: DC voltage application hole

Claims (10)

A conductor film divided into an inner conductor and an outer conductor by a ring-shaped gap and a dielectric thin film laminated on at least one of the upper surface and the lower surface of the conductor film are provided on the dielectric support substrate. A characteristic ring resonator. The ring resonator according to claim 1, wherein a relative dielectric constant of the dielectric thin film is higher than a relative dielectric constant of the dielectric support substrate. 3. The ring resonator according to claim 1, wherein a dielectric loss tangent of the dielectric thin film is higher than a dielectric loss tangent of the dielectric support substrate. The ring resonator according to any one of claims 1 to 3, wherein the gap has a wide portion and a narrow portion. The ring resonator according to claim 4, wherein a ratio of the wide portion in the circumferential direction is larger than a ratio of the narrow portion in the circumferential direction. 6. The ring resonator according to claim 4, wherein the wide portion and the narrow portion are alternately formed by 2k pieces (k: a positive integer). 7. The ring resonator according to claim 1 is electromagnetically excited to measure a resonance frequency and no-load Q of the ring resonator, and the dielectric is calculated from the resonance frequency and the no-load Q. A method for measuring a dielectric property of a dielectric thin film, wherein the dielectric property of the thin film is determined. The ring resonator is magnetically excited so that at least one of the narrow portions of the ring resonator according to any one of claims 4 to 6 has a maximum point of the electric field strength of the resonance electromagnetic field. A method for measuring a dielectric property of a dielectric thin film, comprising: measuring a resonance frequency and no-load Q of the ring resonator, and determining a dielectric property of the dielectric thin film from the resonance frequency and the no-load Q. 7. The ring resonator is magnetically excited so that at least one of the narrow portions of the ring resonator according to claim 6 has a maximum point of the electric field strength of the resonant electromagnetic field, and the electric field strength is generated in the gap. The resonance frequency and no-load Q of an n-th order (n = m × k) resonance mode in which 2m × k local maximum points exist (m, k: positive integer) are measured, and the resonance frequency and the no-load Q are measured. A dielectric property measurement method for a dielectric thin film, comprising: determining a dielectric property of the dielectric thin film from: The dielectric characteristic of the dielectric thin film according to any one of claims 7 to 9, wherein the ring resonator is magnetically excited while a DC voltage is applied between the inner conductor and the outer conductor. Measuring method.

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