JP6787834B2 - Permittivity measurement systems, equipment and methods - Google Patents
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Description
本発明は、電磁波を用いて物体の比誘電率を測定する誘電率測定システム、装置および方法に関するものである。 The present invention relates to a permittivity measuring system, apparatus and method for measuring the relative permittivity of an object using electromagnetic waves.
近年、物品の製造メーカにおいては、製品検査の重要度が増している。特に、食品の製造メーカにおいては、加工食品への異物混入により、会社の信頼性低下や出荷停止など、業績を逼迫する状況になる場合も生じている。製品の出荷検査の段階で、製品への異物混入を検出して、異物が混入した製品の出荷を未然に防ぐことが望ましい。しかしながら、既存の検出装置であるイメージング装置は、金属の検出は可能であるが、昆虫や、製品とは異なる食品などの有機物質を高い精度で検出することはできないという問題点があった。 In recent years, product inspection has become more important in article manufacturers. In particular, food manufacturers may be in a situation where their business performance is tight due to the contamination of processed foods with foreign substances, such as deterioration of company reliability and suspension of shipment. At the stage of product shipment inspection, it is desirable to detect foreign matter mixed in the product and prevent the product containing foreign matter from being shipped. However, although the imaging device, which is an existing detection device, can detect metals, there is a problem that it cannot detect organic substances such as insects and foods different from products with high accuracy.
一方、物体の比誘電率を求めることができれば、物体への異物の混入を検出することが可能になる。従来、電磁波を用いて物体の比誘電率を測定する方法として2周波CW(Continuous Wave)法が提案されている(非特許文献1参照)。測定は、図10(A)に示すように電磁波放射器100と検出器101との間に被測定物がない場合と、図10(B)に示すように被測定物102がある場合の2回行う。 On the other hand, if the relative permittivity of an object can be obtained, it becomes possible to detect the inclusion of foreign matter in the object. Conventionally, a dual frequency CW (Continuous Wave) method has been proposed as a method for measuring the relative permittivity of an object using electromagnetic waves (see Non-Patent Document 1). The measurement is performed when there is no object to be measured between the electromagnetic wave radiator 100 and the detector 101 as shown in FIG. 10 (A) and when there is an object to be measured 102 as shown in FIG. 10 (B). Do it times.
まず、図10(A)の構成で2つの異なる周波数f1とf2の電磁波が空気を透過した後の位相θ1_airとθ2_airを測定する。次に、図10(B)の構成で2つの異なる周波数f1とf2の電磁波が被測定物102を透過した後の位相θ1_sampleとθ2_sampleを測定し、被測定物102がない場合の測定結果との位相変化θ1=θ1_sample−θ1_air、θ2=θ2_sample−θ2_airを算出する。これら位相変化θ1,θ2の差分である位相差θ2−θ1は式(1)で表される。この式(1)により被測定物102の比誘電率εrを算出することができる。式(1)におけるLは被測定物102の厚さ、cは光速である。 First, in the configuration of FIG. 10A, the phases θ 1 _ air and θ 2 _ air after two electromagnetic waves of different frequencies f 1 and f 2 have passed through the air are measured. Next, to measure the phase theta 1 _ sample and theta 2 _ sample after two different electromagnetic waves frequencies f 1 and f 2 are transmitted through the DUT 102 in the configuration of FIG. 10 (B), the object to be measured 102 Calculate the phase change with the measurement result when there is no θ 1 = θ 1 _ sample − θ 1 _ air , θ 2 = θ 2 _ sample − θ 2 _ air . These phase changes theta 1, the phase difference theta 2 - [theta] 1 is the difference between the theta 2 is represented by the formula (1). The relative permittivity ε r of the object to be measured 102 can be calculated by this equation (1). In the formula (1), L is the thickness of the object to be measured 102, and c is the speed of light.
しかしながら実際には、被測定物内部で発生する反射波が原因で位相揺れが発生するため、測定される位相変化には誤差が存在する。非特許文献1に開示された従来の方法で高精度な誘電率測定を行うためには、2周波の間隔Δf=f2−f1をできるだけ拡げる必要がある。 However, in reality, since the phase fluctuation occurs due to the reflected wave generated inside the object to be measured, there is an error in the measured phase change. In order to perform highly accurate permittivity measurement by the conventional method disclosed in Non-Patent Document 1, it is necessary to widen the interval Δf = f 2 −f 1 between two frequencies as much as possible.
図11(A)は、誘電率測定の誤差(比誘電率εrの算出誤差)が2周波の間隔Δfの増大に伴って1/Δfで減少するが、Δfの上限に達すると急激に増大することを示している。図11(B)は、2周波の間隔Δfが狭い場合を示しており、観測される電磁波の位相に、測定環境等に影響される乱れがあるため、この乱れが位相誤差になり、誘電率測定の誤差が大きくなることを示している。一方、図11(C)のように2周波の間隔Δfが拡がると、位相誤差の影響が小さくなり、誘電率測定の誤差が小さくなるが、図11(D)のように2周波間の位相差が2π以上変化すると、測定不能となってしまう(図11(A)のΔfの上限)。以上のように、非特許文献1に開示された方法では、2周波の間隔Δfに上限が存在するため、高い精度で物体の比誘電率を測定することができないという問題があった。 In FIG. 11A, the permittivity measurement error (calculation error of the relative permittivity ε r ) decreases by 1 / Δf as the interval Δf between the two frequencies increases, but increases sharply when the upper limit of Δf is reached. Indicates to do. FIG. 11B shows a case where the interval Δf between the two frequencies is narrow, and since the phase of the observed electromagnetic wave has a turbulence affected by the measurement environment and the like, this turbulence becomes a phase error and the permittivity. It shows that the measurement error becomes large. On the other hand, when the interval Δf between the two frequencies is widened as shown in FIG. 11C, the influence of the phase error is reduced and the error in the permittivity measurement is reduced, but the position between the two frequencies is reduced as shown in FIG. 11D. If the phase difference changes by 2π or more, measurement becomes impossible (upper limit of Δf in FIG. 11A). As described above, the method disclosed in Non-Patent Document 1 has a problem that the relative permittivity of an object cannot be measured with high accuracy because there is an upper limit to the interval Δf between two frequencies.
このような問題を解決する方法として、発明者らは、複数周波数で位相接続を行う方法を提案した(非特許文献2参照)。非特許文献2に開示された誘電率測定方法では、隣接する周波数の間隔fsが式(2)の条件を満たす複数の周波数の電磁波で被測定物を透過した後の電磁波の位相を測定し、測定した各位相に対して位相接続を行い位相の不連続点を補償する(図12)。 As a method for solving such a problem, the inventors have proposed a method for performing phase connection at a plurality of frequencies (see Non-Patent Document 2). In non-patent disclosed in reference 2 a dielectric constant measuring method, to measure the electromagnetic wave of the phase after the interval f s between adjacent frequency is transmitted through the DUT with electromagnetic waves of a plurality of frequencies satisfy the formula (2) , Phase connection is performed for each measured phase to compensate for the phase discontinuity (FIG. 12).
式(2)のεeff_maxは被測定物がとりうる実効的な比誘電率の最大値である。位相接続(アンラップ)は、隣接する2つの周波数の電磁波の位相θnとθn+1間の差分を算出し、算出した差分が0以上の場合には、θn+1以降の位相の全てに0を加算し、差分が負の場合には、θn+1以降の位相の全てに2πを加算する処理である。図12の点120は位相のサンプリング点(位相測定点)を示し、点121は位相接続後の点を示し、直線122は位相の傾きの真値を示している。 Epsilon eff _ max of the formula (2) is the maximum value of the effective dielectric constant of the object to be measured can take. The phase connection (unwrap) calculates the difference between the phases θ n and θ n + 1 of electromagnetic waves of two adjacent frequencies, and if the calculated difference is 0 or more, all the phases after θ n + 1 0 is added to, and if the difference is negative, 2π is added to all the phases after θ n + 1 . Point 120 in FIG. 12 indicates a phase sampling point (phase measurement point), point 121 indicates a point after phase connection, and a straight line 122 indicates a true value of the phase inclination.
非特許文献2に開示された方法では、位相接続を行った後に、最初の位相サンプリング点と位相接続された最後の点とから、図12の直線123で示すような位相の傾きを算出し、式(1)を用いて被測定物の比誘電率を算出する。こうして、非特許文献2に開示された方法では、2周波間隔Δfを広げることができ、比誘電率の測定誤差を低減可能である。 In the method disclosed in Non-Patent Document 2, after the phase connection is performed, the phase inclination as shown by the straight line 123 in FIG. 12 is calculated from the first phase sampling point and the last phase-connected point. The relative permittivity of the object to be measured is calculated using the formula (1). In this way, in the method disclosed in Non-Patent Document 2, the bifrequency interval Δf can be widened, and the measurement error of the relative permittivity can be reduced.
しかしながら実際には、測定に用いる送受信デバイス(例えばアンプ、発振器等)の帯域には制限がある。一般的に中心周波数300GHz付近のデバイスの帯域は300GHzの10%の30GHz程度である。そのため、非特許文献2に開示された方法では、測定に用いる送受信デバイスの帯域を超えて2周波間隔Δfを広げることはできず、更なる測定誤差の低減が難しいという課題があった。 However, in reality, the band of the transmitting / receiving device (for example, an amplifier, an oscillator, etc.) used for measurement is limited. Generally, the band of a device near the center frequency of 300 GHz is about 30 GHz, which is 10% of 300 GHz. Therefore, the method disclosed in Non-Patent Document 2 cannot extend the two-frequency interval Δf beyond the band of the transmission / reception device used for measurement, and has a problem that it is difficult to further reduce the measurement error.
本発明は、上記課題を解決するためになされたもので、複数の周波数の電磁波を用いる誘電率測定方法において、物体の比誘電率の測定誤差を従来よりも更に低減することを目的とする。 The present invention has been made to solve the above problems, and an object of the present invention is to further reduce the measurement error of the relative permittivity of an object in a dielectric constant measuring method using electromagnetic waves of a plurality of frequencies.
本発明の誘電率測定システムは、m個(mは3以上の整数)の周波数f1,f2,・・・,fmの電磁波を被測定物に照射する送信機と、前記被測定物を透過した電磁波を検出して前記被測定物の比誘電率を算出する受信機とを備え、前記送信機は、前記被測定物の想定される最大比誘電率をεeff_max、前記被測定物の既知の厚さをL、光速をcとしたとき、隣接する2つの周波数fn,fn+1(nは1以上(m−1)以下の整数)の間隔fsが
また、本発明の誘電率測定システムの1構成例において、前記位相測定部は、前記送信機と前記受信機のアンテナとの間に背景物質のみがあって前記被測定物がない状態と、前記背景物質と前記被測定物とがある状態のそれぞれで1回ずつ前記位相の測定を行い、前記位相差算出部は、前記背景物質のみがあって前記被測定物がない状態で測定された電磁波の位相と前記背景物質と前記被測定物とがある状態で測定された電磁波の位相との差である位相変化を周波数毎に算出し、隣接する2つの周波数fn,fn+1の電磁波の位相変化θnとθn+1との差を、これら周波数fn,fn+1の電磁波の位相差とし、前記更新処理部は、前記位相差算出部によって算出された位相差が負の場合にfn+1以降の各周波数の電磁波の位相変化θn+1,θn+2,・・・,θmのそれぞれに2πを加算して更新する処理を、n=1からn=m−1まで繰り返し、前記近似部は、m個の周波数f1,f2,・・・,fmのうちの最低の周波数f1の電磁波の位相変化θ1と、f1を除くm−1個の周波数f2,・・・,fmの電磁波の位相θ2,・・・,θmを前記更新処理部によって更新した後の位相変化φ2,・・・,φmとを直線近似することを特徴とするものである。 Further, in one configuration example of the dielectric constant measuring system of the present invention, the phase measuring unit is in a state where there is only a background material between the transmitter and the antenna of the receiver and there is no object to be measured. The phase is measured once for each of the background material and the object to be measured, and the phase difference calculation unit measures the electromagnetic wave with only the background material and no object to be measured. The phase change, which is the difference between the phase of the above and the phase of the electromagnetic wave measured in a certain state between the background material and the object to be measured, is calculated for each frequency, and the electromagnetic waves of two adjacent frequencies f n and f n + 1 are calculated. The difference between the phase change θ n and θ n + 1 of the above is taken as the phase difference of the electromagnetic waves having these frequencies f n and f n + 1 , and the phase difference calculated by the phase difference calculation unit is negative in the update processing unit. In the case of, the process of adding 2π to each of the phase changes θ n + 1 , θ n + 2 , ···, and θ m of the electromagnetic waves of each frequency after f n + 1 and updating is performed from n = 1 to n. Repeating up to = m-1, the approximation part is the phase change θ 1 of the electromagnetic wave of the lowest frequency f 1 among m frequencies f 1 , f 2 , ..., F m , and m excluding f 1. -1 frequency f 2,..., the phase theta 2 of the electromagnetic wave of f m, ..., theta m the update processing unit phase change phi 2 after updating by, ..., and phi m It is characterized by linear approximation.
また、本発明の誘電率測定装置は、被測定物を透過したm個(mは3以上の整数)の周波数f1,f2,・・・,fmの電磁波を受信するアンテナと、このアンテナで受信されたm個の周波数f1,f2,・・・,fmの電磁波のそれぞれの位相を測定する位相測定部と、この位相測定部の測定結果を基に隣接する2つの周波数fn,fn+1(nは1以上(m−1)以下の整数)の電磁波の位相差を算出する位相差算出部と、この位相差算出部によって算出された位相差が負の場合にfn+1以降の各周波数の電磁波の位相のそれぞれに2πを加算して更新する処理を、n=1からn=m−1まで繰り返す更新処理部と、m個の周波数f1,f2,・・・,fmのうちの最低の周波数f1の電磁波の位相と、f1を除くm−1個の周波数f2,・・・,fmの電磁波の位相を前記更新処理部によって更新した後の位相とを直線近似する近似部と、この近似部によって得られた近似直線の傾きと前記被測定物の既知の厚さLとから、前記被測定物の比誘電率を算出する比誘電率算出部とを備え、前記m個の周波数f1,f2,・・・,fmの電磁波は、前記被測定物の想定される最大比誘電率をεeff_max、光速をcとしたとき、隣接する2つの周波数fn,fn+1の間隔fsが
また、本発明の誘電率測定方法は、被測定物の想定される最大比誘電率をεeff_max、前記被測定物の既知の厚さをL、光速をcとしたとき、隣接する2つの周波数fn,fn+1の間隔fsが
本発明によれば、隣接する2つの周波数の間隔fsを適切に設定したm個の周波数の電磁波を被測定物に照射し、被測定物を透過したm個の周波数の電磁波を受信して、電磁波のそれぞれの位相を測定し、この測定結果を基に隣接する2つの周波数fn,fn+1の電磁波の位相差を算出し、算出した位相差が負の場合にfn+1以降の各周波数の電磁波の位相のそれぞれに2πを加算して更新する処理を、n=1からn=m−1まで繰り返し、m個の周波数のうちの最低の周波数f1の電磁波の位相と、f1を除くm−1個の周波数f2,・・・,fmの電磁波の更新後の位相とを直線近似し、近似直線の傾きと被測定物の厚さLとから、被測定物の比誘電率を算出することにより、送受信デバイスによって制限される周波数間隔Δf=fm−f1の範囲内で、被測定物の比誘電率を従来よりも高い精度で検出することができる。 According to the present invention, by receiving electromagnetic waves of two adjacent m number of electromagnetic waves with a frequency appropriate set the interval f s frequency is irradiated to the measurement object, the m frequencies transmitted through the DUT , Each phase of the electromagnetic wave is measured, and the phase difference of the electromagnetic waves of two adjacent frequencies f n and f n + 1 is calculated based on the measurement result, and when the calculated phase difference is negative, f n + 1 The process of adding 2π to each of the phases of the electromagnetic waves of each subsequent frequency and updating is repeated from n = 1 to n = m-1, and the phase of the electromagnetic wave having the lowest frequency f 1 among the m frequencies is used. , m-1 pieces of frequency f 2 with the exception of f 1, · · ·, linear approximation the phase after the electromagnetic wave updates f m, and a thickness L of the slope and the object to be measured of the approximate straight line, to be measured By calculating the specific dielectric constant of an object, the specific dielectric constant of the object to be measured can be detected with higher accuracy than before within the range of the frequency interval Δf = f m −f 1 limited by the transmitting / receiving device. ..
[発明の原理]
本発明では、図1のように隣接する周波数の間隔fs=fn+1−fnが以下の式(3)を満たす複数の周波数f1,f2,・・・,fn,fn+1,・・・,fm-1,fmの電磁波で被測定物を透過した後の電磁波の位相を測定する(mは3以上の整数、nは1以上(m−1)以下の整数)。このとき、電磁波の周波数fnにおいて検出した位相(被測定物がないときと被測定物があるときの位相変化)をθnとする。図1の白丸印は位相のサンプリング点(位相測定点)を示している。
[Principle of invention]
In the present invention, as shown in FIG. 1, a plurality of frequencies f 1 , f 2 , ..., f n , f in which the intervals f s = f n + 1 −f n of adjacent frequencies satisfy the following equation (3). Measure the phase of the electromagnetic wave after it has passed through the object to be measured by the electromagnetic waves of n + 1 , ..., f m-1 , f m (m is an integer of 3 or more, n is 1 or more (m-1) or less). Integer). At this time, let θ n be the phase detected at the frequency f n of the electromagnetic wave (the phase change when there is no object to be measured and when there is an object to be measured). The white circles in FIG. 1 indicate the phase sampling points (phase measurement points).
式(3)におけるLは被測定物の厚さ、cは光速、εeff_maxは被測定物がとりうる実効的な比誘電率の最大値である。本発明により誘電率測定を行う場合、εeff_maxについては、予め設定した固定値を使用する。 In the formula (3), L is the thickness of the object to be measured, c is the speed of light, and ε eff _max is the maximum value of the effective relative permittivity that the object to be measured can take. When the permittivity is measured according to the present invention, a preset fixed value is used for ε eff _ max .
次に、従来と同様に測定した各位相に対して位相接続を行う。具体的には、隣接する2つの周波数fn,fn+1の電磁波の位相θnとθn+1間の差分を算出し、算出した差分が負の場合には、θn+1以降の位相θn+1,θn+2,・・・,θmの全てに2πを加算して更新する。差分が0以上の場合には、位相θn+1,θn+2,・・・,θmの全てに0を加算すればよい。すなわち、差分が0以上の場合には値の更新は不要である。 Next, a phase connection is made for each phase measured in the same manner as in the conventional case. Specifically, the difference between the phases θ n and θ n + 1 of electromagnetic waves of two adjacent frequencies f n and f n + 1 is calculated, and if the calculated difference is negative, θ n + 1 or later. 2π is added to all of the phases θ n + 1 , θ n + 2 , ···, θ m of to update. When the difference is 0 or more, 0 may be added to all of the phases θ n + 1 , θ n + 2 , ..., θ m . That is, when the difference is 0 or more, it is not necessary to update the value.
以上のような更新ステップを、n=1からn=m−1まで繰り返す。n=m−1までの更新ステップが完了した後の位相θn+1,θn+2,・・・,θmを、φn+1,φn+2,・・・,φmとする。図1の黒丸印は位相接続後の点を示している。なお、周波数f1の電磁波の位相θ1は更新の対象とならないため、φ1とせず、θ1のままとしている。 The above update step is repeated from n = 1 to n = m-1. After the update step up to n = m-1, the phases θ n + 1 , θ n + 2 , ···, θ m are changed to φ n + 1 , φ n + 2 , ···, φ m . To do. The black circles in FIG. 1 indicate the points after the phase connection. Since the phase theta 1 of the electromagnetic wave of frequency f 1 is not subject to update, without phi 1, is set to remain theta 1.
続いて、位相接続後の各位相θ1,φ2,・・・,φn,φn+1,・・・,φmに対して最小二乗法による直線近似を行う。最後に、近似直線の傾きαから式(4)を用いて被測定物の比誘電率εrを算出する。 Subsequently, a linear approximation is performed by the least squares method for each phase θ 1 , φ 2 , ···, φ n , φ n + 1 , ···, φ m after phase connection. Finally, the relative permittivity ε r of the object to be measured is calculated from the slope α of the approximate straight line using Eq. (4).
図1の直線50は従来の位相接続で得られる直線を示し、直線51は本発明の直線近似で得られる直線を示し、直線52は位相の傾きの真値を示している。
本発明によれば、被測定物内の反射波に起因する電磁波の位相の揺れによる誤差を平均化し、送受信デバイスによって制限されたΔfの範囲内で、測定誤差をさらに低減可能である。
The straight line 50 in FIG. 1 shows a straight line obtained by the conventional phase connection, the straight line 51 shows the straight line obtained by the straight line approximation of the present invention, and the straight line 52 shows the true value of the phase inclination.
According to the present invention, it is possible to average the error due to the phase fluctuation of the electromagnetic wave caused by the reflected wave in the object to be measured, and further reduce the measurement error within the range of Δf limited by the transmission / reception device.
次に、式(3)の導出について説明する。図1に示す周波数軸上の位相θ1,θ2,・・・,θn,θn+1,・・・,θmの揺れは基本波(反射せずに透過する波)と反射波との干渉、そして反射波同士の干渉によって起きる。位相の揺れは各干渉波の伝搬長差に応じた周期関数の重なりで構成される。そのため、位相の揺れの1/2周期より細かい周波数間隔で1周期以上サンプリングし、直線近似することで、位相の揺れが平均化され、その影響を低減可能である。 Next, the derivation of the equation (3) will be described. The fluctuations of the phases θ 1 , θ 2 , ···, θ n , θ n + 1 , ···, θ m on the frequency axis shown in FIG. 1 are the fundamental wave (wave transmitted without reflection) and the reflected wave. It is caused by the interference with and the interference between the reflected waves. The phase fluctuation is composed of the overlap of periodic functions according to the difference in propagation length of each interference wave. Therefore, by sampling one cycle or more at a frequency interval finer than 1/2 cycle of the phase fluctuation and linearly approximating the phase fluctuation, the phase fluctuation can be averaged and its influence can be reduced.
説明のために、例として図2のような、周囲が空気(比誘電率ε1=1)で囲まれた、比誘電率ε2=3、厚さL=30mmの被測定物10を考える。被測定物10内では基本波と2回反射波のみが存在すると仮定する。なお、図2では、説明を分かり易くするために基本波と2回反射波とが位置的に離れているように記載しているが、実際には基本波と2回反射波とは同じ位置で重なって発生する波である。 For the sake of explanation, consider an object 10 having a relative permittivity ε 2 = 3 and a thickness L = 30 mm, as shown in FIG. 2, surrounded by air (relative permittivity ε 1 = 1). .. It is assumed that only the fundamental wave and the double reflected wave exist in the object 10 to be measured. In FIG. 2, for the sake of clarity, the fundamental wave and the double reflected wave are described so as to be separated from each other in position, but in reality, the fundamental wave and the double reflected wave are at the same position. It is a wave generated by overlapping with.
基本波と2回反射波の伝搬長差Dは式(5)のように表される。 The propagation length difference D between the fundamental wave and the double reflected wave is expressed by Eq. (5).
また、基本波と2回反射波とによる電磁波の位相揺れの周期CYは式(6)のように表される(図3)。 Further, the period CY of the phase fluctuation of the electromagnetic wave due to the fundamental wave and the twice reflected wave is expressed by the equation (6) (FIG. 3).
すなわち、基本波と2回反射波の伝搬長差Dが大きいほど、図3の周波数軸上での位相θの揺れの周期CYが細かくなる。被測定物10内の反射波として、2回反射波のみが存在する場合、式(7)に示す周波数間隔fsで位相揺れの1周期以上にわたり被測定物10を透過した後の電磁波の位相θを測定し、各位相θから近似直線を求めることで、位相θの揺れの影響が軽減され、所望の位相傾きを得ることができる。 That is, the larger the propagation length difference D between the fundamental wave and the twice reflected wave, the finer the period CY of the fluctuation of the phase θ on the frequency axis of FIG. As a reflected wave in the object to be measured 10 twice when only the reflected wave is present, the electromagnetic waves after passing through the object to be measured 10 for more than one period of the phase swing at a frequency interval f s shown in Equation (7) Phase By measuring θ and obtaining an approximate straight line from each phase θ, the influence of the fluctuation of the phase θ is reduced, and a desired phase gradient can be obtained.
一方で、実際の被測定物10内では、2回反射、4回反射・・・というように無限回の反射が発生する。全ての反射波による影響を打ち消すためには、無限に細かい周波数間隔の電磁波で位相θを測定する必要がある。しかし、反射波のエネルギーEは、被測定物10内での電磁波の反射回数nに応じて、式(8)のように減衰する。 On the other hand, in the actual object 10 to be measured, infinite reflections occur, such as two reflections, four reflections, and so on. In order to cancel the influence of all reflected waves, it is necessary to measure the phase θ with electromagnetic waves with infinitely fine frequency intervals. However, the energy E of the reflected wave is attenuated as in the equation (8) according to the number of reflections n of the electromagnetic wave in the object to be measured 10.
つまり、4回反射以降の反射波のエネルギーは大きく減衰するため、2回反射波が位相θの揺れに一番影響する。そのため、2回反射の中で基本波との伝搬長差Dが一番長い場合(位相θの揺れが一番細かい場合)に合わせて、測定に用いる電磁波の周波数の間隔fsを選ぶことが望ましい。
被測定物10の実効誘電率の最大値がεeff_maxの場合、2回反射の中で基本波との一番大きい伝搬長差Dmaxは式(9)のように表される。
That is, since the energy of the reflected wave after the fourth reflection is greatly attenuated, the second reflected wave has the greatest influence on the fluctuation of the phase θ. Therefore, when the propagation length difference D between the fundamental wave in two reflection longest to fit (if shaking of the phase θ is the most fine), to choose the interval f s of the frequency of electromagnetic waves used for the measurement desirable.
When the maximum value of the effective permittivity of the object 10 to be measured is ε eff _ max , the largest propagation length difference D max from the fundamental wave among the two reflections is expressed by Eq. (9).
したがって、位相θの揺れの1周期以上の周波数範囲にわたって、周波数間隔fsが式(3)を満たす複数の周波数の電磁波で位相θを測定し、各位相θに対して直線近似を行うことで、伝搬長差Dmaxによる位相θの揺れの影響およびDmaxよりも短い伝搬長差Dによる位相θの揺れの影響を低減することができる。 Therefore, the phase θ is measured by electromagnetic waves of a plurality of frequencies whose frequency interval f s satisfies the equation (3) over a frequency range of one cycle or more of the fluctuation of the phase θ, and a linear approximation is performed for each phase θ. , The influence of the fluctuation of the phase θ due to the propagation length difference D max and the influence of the fluctuation of the phase θ due to the propagation length difference D shorter than D max can be reduced.
[実施例]
以下、本発明の実施例について図面を参照して説明する。図4は本発明の実施例に係る誘電率測定システムの構成を示すブロック図である。誘電率測定システムは、m個(mは3以上の整数)の周波数f1,f2,・・・,fmの電磁波を被測定物10に照射する送信機1と、被測定物10を透過した電磁波を検出して被測定物10の比誘電率εrを算出する受信機2(誘電率測定装置)とから構成される。
受信機2は、アンテナ20と、位相測定部21と、位相差算出部22と、更新処理部23と、近似部24と、比誘電率算出部25と、算出結果出力部26とを備えている。
[Example]
Hereinafter, examples of the present invention will be described with reference to the drawings. FIG. 4 is a block diagram showing a configuration of a permittivity measurement system according to an embodiment of the present invention. The permittivity measurement system uses a transmitter 1 that irradiates the object 10 with electromagnetic waves of frequencies f 1 , f 2 , ..., F m of m (m is an integer of 3 or more) and the object 10 to be measured. It is composed of a receiver 2 (permittivity measuring device) that detects the transmitted electromagnetic wave and calculates the relative permittivity ε r of the object 10 to be measured.
The receiver 2 includes an antenna 20, a phase measurement unit 21, a phase difference calculation unit 22, an update processing unit 23, an approximation unit 24, a relative permittivity calculation unit 25, and a calculation result output unit 26. There is.
図5は本実施例の誘電率測定システムの動作を説明するフローチャートである。まず、比誘電率ε1が既知の背景物質11(例えば空気)のみがあって被測定物10がない状態で送信機1は、m個の周波数f1,f2,・・・,fmの電磁波を背景物質11に照射する(図5ステップS100)。 FIG. 5 is a flowchart illustrating the operation of the permittivity measurement system of this embodiment. First, the relative dielectric constant ε transmitter 1 1 in the absence of the object to be measured 10 when there is only known background material 11 (e.g., air), m pieces of frequency f 1, f 2, ···, f m The background material 11 is irradiated with the electromagnetic waves of (FIG. 5, step S100).
上記のとおり、隣接する2つの周波数の間隔fs=fn+1−fnは式(3)を満たしている。本実施例では、食品における異物混入検出などの用途を想定しているので、実効的な比誘電率の最大値εeff_maxについては、異物の最大誘電率を考慮して、想定される値を予め設定しておけばよい。また、本実施例では、送信機1からアンテナ20への方向の被測定物10の厚さLは既知の値である。なお、送信機1は、例えばGHzオーダーの複数の周波数の電磁波を物体に照射できるものであればよい。 As described above, the distance f s = f n + 1 −f n between two adjacent frequencies satisfies the equation (3). In this embodiment, it is assumed the use of such contamination detection in food, for the maximum value epsilon eff _ max of the effective dielectric constant, in consideration of the maximum dielectric constant of the foreign matter, the possible values Should be set in advance. Further, in this embodiment, the thickness L of the object to be measured 10 in the direction from the transmitter 1 to the antenna 20 is a known value. The transmitter 1 may be any one capable of irradiating an object with electromagnetic waves having a plurality of frequencies on the order of GHz, for example.
受信機2のアンテナ20は、背景物質11を透過したm個の周波数f1,f2,・・・,fmの電磁波を受信する(図5ステップS101)。
受信機2の位相測定部21は、アンテナ20で受信されたm個の周波数f1,f2,・・・,fmの電磁波のそれぞれの位相を測定する(図5ステップS102)。なお、電磁波の位相(正確には送信機1側の基準の信号に対する受信機2で受信した信号の位相の変化量)を測定する技術は、例えばネットワークアナライザー(VNA:Network Analyzer)などの既存の測定器を使用して実現できる周知の技術である。
Antenna 20 of the receiver 2, m pieces of frequency f 1 that has passed through the background material 11, f 2, ···, receives an electromagnetic wave of f m (Fig. 5 step S101).
The phase measuring unit 21 of the receiver 2 measures the phases of the electromagnetic waves of m frequencies f 1 , f 2 , ..., And fm received by the antenna 20 (step S102 in FIG. 5). A technique for measuring the phase of an electromagnetic wave (to be exact, the amount of change in the phase of a signal received by the receiver 2 with respect to a reference signal on the transmitter 1 side) is an existing technique such as a network analyzer (VNA). It is a well-known technique that can be realized using a measuring instrument.
次に、誘電率測定システムを使用するユーザは、背景物質11の内部、またはその上部に、厚さLが既知で、比誘電率εrが未知の被測定物10を配置する。
送信機1は、このように被測定物10が配置された状態で、背景物質11および被測定物10にm個の周波数f1,f2,・・・,fmの電磁波を照射する(図5ステップS103)。
Next, the user who uses the permittivity measurement system places the object 10 to be measured having a known thickness L and an unknown relative permittivity ε r inside or above the background substance 11.
With the object 10 to be measured arranged in this way, the transmitter 1 irradiates the background substance 11 and the object 10 to be measured with electromagnetic waves having frequencies f 1 , f 2 , ..., F m ( m ). FIG. 5 step S103).
受信機2のアンテナ20は、背景物質11および被測定物10を透過したm個の周波数f1,f2,・・・,fmの電磁波を受信する(図5ステップS104)。
受信機2の位相測定部21は、アンテナ20で受信されたm個の周波数f1,f2,・・・,fmの電磁波のそれぞれの位相を測定する(図5ステップS105)。
Antenna 20 of the receiver 2, the background material 11 and the m frequency f 1 which has transmitted through the DUT 10, f 2, · · ·, receives an electromagnetic wave of f m (Fig. 5 step S104).
The phase measuring unit 21 of the receiver 2 measures the phases of the electromagnetic waves of m frequencies f 1 , f 2 , ..., And fm received by the antenna 20 (step S105 in FIG. 5).
続いて、受信機2の位相差算出部22は、ステップS102で得られた電磁波の位相とステップS105で得られた電磁波の位相との差である位相変化θを電磁波の周波数毎に算出し、隣接する2つの周波数fn,fn+1(nは1以上(m−1)以下の整数)の電磁波の位相変化θnとθn+1との差θn+1−θnを、2つの周波数fn,fn+1の電磁波の位相差Δθとする(図5ステップS106)。このように、本実施例では、2回の位相の測定結果の差分をとることで得られる被測定物10による正味の位相変化をθとする。位相差算出部22は、以上のような位相差Δθの算出をn=1からn=m−1までのそれぞれについて行う。 Subsequently, the phase difference calculation unit 22 of the receiver 2 calculates the phase change θ, which is the difference between the phase of the electromagnetic wave obtained in step S102 and the phase of the electromagnetic wave obtained in step S105, for each frequency of the electromagnetic wave. two adjacent frequencies f n, the f n + 1 (n is 1 or more (m-1) an integer) difference θ n + 1 -θ n of the phase change theta n and theta n + 1 of an electromagnetic wave, Let the phase difference Δθ of electromagnetic waves having two frequencies f n and f n + 1 (step S106 in FIG. 5). As described above, in this embodiment, the net phase change due to the object 10 to be measured obtained by taking the difference between the two phase measurement results is defined as θ. The phase difference calculation unit 22 calculates the phase difference Δθ as described above for each of n = 1 to n = m-1.
次に、受信機2の更新処理部23は、隣接する2つの周波数fn,fn+1の電磁波の位相差Δθが負かどうかを判定し(図5ステップS108)、位相差Δθが負の場合には、θn+1以降の位相変化θn+1,θn+2,・・・,θmのそれぞれに2πを加算して更新する(図5ステップS109)。上記のとおり、位相差Δθが0以上の場合には、位相変化θn+1,θn+2,・・・,θmのそれぞれに0を加算することになるので、位相差Δθが0以上の場合には位相変化の更新は不要である。このような更新ステップを、n=1から開始して、nを1ずつ増やしながら繰り返し行い(図5ステップS107〜S110)、n=m−1まで処理を終えた時点で(図5ステップS111においてYES)、更新処理部23の動作が終了する。上記のとおり、n=m−1までの更新ステップが完了した後の位相変化θn+1,θn+2,・・・,θmを、φn+1,φn+2,・・・,φmとする。 Next, the update processing unit 23 of the receiver 2 determines whether or not the phase difference Δθ of the electromagnetic waves of two adjacent frequencies f n and f n + 1 is negative (step S108 in FIG. 5), and the phase difference Δθ is negative. in the case of, θ n + 1 and subsequent phase change θ n + 1, θ n + 2, ···, and updates by adding 2π to each theta m (Fig. 5 step S109). As described above, when the phase difference Δθ is 0 or more, 0 is added to each of the phase changes θ n + 1 , θ n + 2 , ..., θ m , so that the phase difference Δθ is 0. In the above cases, it is not necessary to update the phase change. Such an update step is repeated starting from n = 1 and increasing n by 1 (steps S107 to S110 in FIG. 5), and when the processing is completed up to n = m-1 (in step S111 in FIG. 5). YES), the operation of the update processing unit 23 ends. As described above, the phase changes θ n + 1 , θ n + 2 , ..., θ m after the update step up to n = m-1 is completed, φ n + 1 , φ n + 2 , ...・, Φ m .
なお、ステップS109の処理を繰り返すことにより、位相変化θn+1,θn+2,・・・,θmが増大していくが、ステップS109の処理後においても隣接する2つの周波数fn,fn+1の電磁波の位相差Δθは変化しない。したがって、ステップS109の処理を1回行う度に位相差Δθを計算し直す必要はなく、位相差算出部22の算出結果を基にステップS108の判定処理を行うようにすればよい。 By repeating the process of step S109, the phase changes θ n + 1 , θ n + 2 , ..., θ m increase, but even after the process of step S109, the two adjacent frequencies f n , The phase difference Δθ of the electromagnetic wave of f n + 1 does not change. Therefore, it is not necessary to recalculate the phase difference Δθ each time the process of step S109 is performed, and the determination process of step S108 may be performed based on the calculation result of the phase difference calculation unit 22.
受信機2の近似部24は、m個の周波数f1,f2,・・・,fmのうちの最低の周波数f1の電磁波の位相変化θ1とf1を除くm−1個の周波数f2,・・・,fmの電磁波の更新後の位相変化φ2,・・・,φmとを最小二乗法により直線近似する(図5ステップS112)。 The approximation part 24 of the receiver 2 has m-1 pieces excluding the phase changes θ 1 and f 1 of the electromagnetic wave having the lowest frequency f 1 among m frequencies f 1 , f 2 , ..., F m . The phase change φ 2 , ..., φ m after the update of the electromagnetic wave of the frequencies f 2 , ..., F m is linearly approximated by the minimum square method (step S112 in FIG. 5).
受信機2の比誘電率算出部25は、近似部24によって得られた近似直線の傾きαと、被測定物10の既知の厚さLとを用いて、式(4)により被測定物10の比誘電率εrを算出する(図5ステップS113)。 The relative permittivity calculation unit 25 of the receiver 2 uses the slope α of the approximate straight line obtained by the approximate unit 24 and the known thickness L of the object 10 to be measured, and the object 10 to be measured according to the equation (4). The relative permittivity ε r of is calculated (FIG. 5, step S113).
受信機2の算出結果出力部26は、比誘電率算出部25の算出結果を出力する(図5ステップS114)。具体的には、算出結果出力部26は、例えば比誘電率算出部25が算出した被測定物10の比誘電率εrを表示したり、比誘電率εrの情報を外部に送信したりする。以上のようにして、本実施例の誘電率測定システムの動作が終了する。 The calculation result output unit 26 of the receiver 2 outputs the calculation result of the relative permittivity calculation unit 25 (step S114 of FIG. 5). Specifically, the calculation result output unit 26, and transmits for example, specific to view the relative dielectric constant epsilon r of the object to be measured 10 a dielectric constant calculator 25 has calculated, the information of the relative permittivity epsilon r to the outside To do. As described above, the operation of the permittivity measurement system of this embodiment is completed.
本実施例では、従来との比較のため、1例として図6に示すような比誘電率ε1=3、厚さL1=30mmの背景物質11の中に比誘電率εr=10で厚さL=2〜10mmの範囲の被測定物10が入っている場合について本実施例の効果を説明する。この条件の場合、実効誘電率の最大値εeff_maxは4.88である。式(3)から計算される、本実施例で必要な周波数間隔fsは1.2GHzより小さい値とする必要がある。 In this embodiment, for comparison with the conventional case, as an example, the relative permittivity ε r = 10 in the background material 11 having a relative permittivity ε 1 = 3 and a thickness L 1 = 30 mm as shown in FIG. The effect of this embodiment will be described when the object to be measured 10 having a thickness L = 2 to 10 mm is contained. Under this condition, the maximum value of the effective permittivity ε eff _max is 4.88. Is calculated from equation (3), the frequency interval f s required in the present embodiment is required to be 1.2GHz smaller value.
非特許文献1に開示された従来の方法において、f1=300GHzとf2=308GHzの2周波を用いた場合の誘電率測定誤差(比誘電率εrの算出誤差)のシミュレーション結果を図7に示す。この場合、2周波の間隔は8GHzとなる。図7の点線70が非特許文献1に開示された方法で被測定物10の比誘電率εrを算出した場合の誤差を示している。最大誤差は14.5%であった。 FIG. 7 shows a simulation result of a permittivity measurement error (calculation error of relative permittivity ε r ) when two frequencies of f 1 = 300 GHz and f 2 = 308 GHz are used in the conventional method disclosed in Non-Patent Document 1. Shown in. In this case, the interval between the two frequencies is 8 GHz. The dotted line 70 in FIG. 7 shows an error when the relative permittivity ε r of the object to be measured 10 is calculated by the method disclosed in Non-Patent Document 1. The maximum error was 14.5%.
図7の一点鎖線71は非特許文献2に開示された従来の方法で被測定物10の比誘電率εrを算出した場合の誤差を示している。ここでは、f1=300GHz、f2=308GHz、f3=316GHz、f4=324GHz、f5=330GHzの5つの周波を用いて、電磁波の最低周波数と最高周波数の周波数間隔Δfを30GHzまで拡張した。この方法の場合の最大誤差は3.7%であった。 The alternate long and short dash line 71 in FIG. 7 shows an error when the relative permittivity ε r of the object to be measured 10 is calculated by the conventional method disclosed in Non-Patent Document 2. Here, the frequency interval Δf between the lowest frequency and the highest frequency of the electromagnetic wave is extended to 30 GHz by using five frequencies of f 1 = 300 GHz, f 2 = 308 GHz, f 3 = 316 GHz, f 4 = 324 GHz, and f 5 = 330 GHz. did. The maximum error for this method was 3.7%.
一方、図7の実線72は本実施例の方法で被測定物11の比誘電率εrを算出した場合の誤差を示している。この例では、f1=300GHzからf31=330GHzまでの1GHz間隔の31周波を用いた。シミュレーションの結果、最大誤差を0.86%まで低減可能なことが分かった。 On the other hand, the solid line 72 in FIG. 7 shows an error when the relative permittivity ε r of the object to be measured 11 is calculated by the method of this embodiment. In this example, 31 frequencies at 1 GHz intervals from f 1 = 300 GHz to f 31 = 330 GHz were used. As a result of the simulation, it was found that the maximum error can be reduced to 0.86%.
次に、被測定物10の別の例として、図8に示すように縦横50mm、厚さL=21mmのチョコレート10aの中に合成樹脂からなる異物10bが入った被測定物10の場合について本実施例の効果を説明する。 Next, as another example of the object to be measured 10, as shown in FIG. 8, the case of the object 10 to be measured in which a foreign substance 10b made of a synthetic resin is contained in chocolate 10a having a length and width of 50 mm and a thickness of L = 21 mm is described. The effect of the embodiment will be described.
図9(A)は非特許文献1に開示された方法により図8の被測定物10の比誘電率εrを測定した結果を示す図、図9(B)は非特許文献2に開示された方法により被測定物10の比誘電率εrを測定した結果を示す図、図9(C)は本実施例の方法により被測定物10の比誘電率εrを測定した結果を示す図である。図9(A)、図9(B)、図9(C)では、被測定物10の面内の比誘電率εrの分布を色分けで示している。ここで、非特許文献1に開示された方法については、f1=280GHzとf2=288GHzの2周波を用いた。非特許文献2および本実施例の方法については、f1=280GHzからf6=310GHzまでの6GHz間隔の6周波を用いた。 FIG. 9 (A) is a diagram showing the result of measuring the relative permittivity ε r of the object to be measured 10 of FIG. 8 by the method disclosed in Non-Patent Document 1, and FIG. 9 (B) is disclosed in Non-Patent Document 2. shows the results of measuring the relative dielectric constant epsilon r of the object to be measured 10 by methods, shows the FIG. 9 (C) is the result of the measurement of the relative dielectric constant epsilon r of the object to be measured 10 by the method of the present embodiment Is. 9 (A), 9 (B), and 9 (C) show the distribution of the relative permittivity ε r in the plane of the object to be measured 10 in different colors. Here, as for the method disclosed in Non-Patent Document 1, two frequencies of f 1 = 280 GHz and f 2 = 288 GHz were used. For Non-Patent Document 2 and the method of this example, 6 frequencies at 6 GHz intervals from f 1 = 280 GHz to f 6 = 310 GHz were used.
図9(D)、図9(E)、図9(F)はそれぞれ図9(A)、図9(B)、図9(C)の直線Aの位置の比誘電率εrを示す図である。図9(D)、図9(E)、図9(F)の90は比誘電率εrの理論値を示し、91は非特許文献1に開示された方法による測定結果を示し、92は非特許文献2に開示された方法による測定結果を示し、93は本実施例の方法による測定結果を示している。異物10bの位置の比誘電率εrの測定誤差は、非特許文献1に開示された方法の場合で3.6%、非特許文献2に開示された方法の場合で1.3%、本実施例の方法の場合で0.29%であった。 9 (D), 9 (E), and 9 (F) show the relative permittivity ε r at the position of the straight line A in FIGS. 9 (A), 9 (B), and 9 (C), respectively. Is. 90 in FIGS. 9 (D), 9 (E), and 9 (F) shows the theoretical value of the relative permittivity ε r , 91 shows the measurement result by the method disclosed in Non-Patent Document 1, and 92 shows the measurement result by the method disclosed in Non-Patent Document 1. The measurement result by the method disclosed in Non-Patent Document 2 is shown, and 93 shows the measurement result by the method of this Example. The measurement error of the relative permittivity ε r at the position of the foreign matter 10b is 3.6% in the case of the method disclosed in Non-Patent Document 1 and 1.3% in the case of the method disclosed in Non-Patent Document 2. In the case of the method of the example, it was 0.29%.
本実施例で説明した位相測定部21と位相差算出部22と更新処理部23と近似部24と比誘電率算出部25と算出結果出力部26とは、CPU(Central Processing Unit)、記憶装置及びインタフェースを備えたコンピュータと、これらのハードウェア資源を制御するプログラムによって実現することができる。本発明の誘電率測定方法を実現させるためのプログラムは、フレキシブルディスク、CD−ROM、DVD−ROM、メモリカードなどの記録媒体に記録された状態で提供され、記憶装置に格納される。コンピュータのCPUは、記憶装置に格納されたプログラムに従って本実施例で説明した処理を実行する。 The phase measurement unit 21, the phase difference calculation unit 22, the update processing unit 23, the approximation unit 24, the relative permittivity calculation unit 25, and the calculation result output unit 26 described in this embodiment are a CPU (Central Processing Unit) and a storage device. It can be realized by a computer equipped with an interface and a program that controls these hardware resources. The program for realizing the permittivity measuring method of the present invention is provided in a state of being recorded on a recording medium such as a flexible disk, a CD-ROM, a DVD-ROM, or a memory card, and is stored in a storage device. The CPU of the computer executes the process described in this embodiment according to the program stored in the storage device.
本発明は、電磁波を用いて物体の比誘電率を測定する技術に適用することができる。 The present invention can be applied to a technique for measuring the relative permittivity of an object using electromagnetic waves.
1…送信機、2…受信機、10…被測定物、11…背景物質、20…アンテナ、21…位相測定部、22…位相差算出部、23…更新処理部、24…近似部、25…比誘電率算出部、26…算出結果出力部。 1 ... Transmitter, 2 ... Receiver, 10 ... Object to be measured, 11 ... Background material, 20 ... Antenna, 21 ... Phase measurement unit, 22 ... Phase difference calculation unit, 23 ... Update processing unit, 24 ... Approximation unit, 25 ... Relative permittivity calculation unit, 26 ... Calculation result output unit.
Claims (6)
前記被測定物を透過した電磁波を検出して前記被測定物の比誘電率を算出する受信機とを備え、
前記送信機は、前記被測定物の想定される最大比誘電率をεeff_max、前記被測定物の既知の厚さをL、光速をcとしたとき、隣接する2つの周波数fn,fn+1(nは1以上(m−1)以下の整数)の間隔fsが
前記受信機は、
前記被測定物を透過したm個の周波数f1,f2,・・・,fmの電磁波を受信するアンテナと、
このアンテナで受信されたm個の周波数f1,f2,・・・,fmの電磁波のそれぞれの位相を測定する位相測定部と、
この位相測定部の測定結果を基に隣接する2つの周波数fn,fn+1の電磁波の位相差を算出する位相差算出部と、
この位相差算出部によって算出された位相差が負の場合にfn+1以降の各周波数の電磁波の位相のそれぞれに2πを加算して更新する処理を、n=1からn=m−1まで繰り返す更新処理部と、
m個の周波数f1,f2,・・・,fmのうちの最低の周波数f1の電磁波の位相と、f1を除くm−1個の周波数f2,・・・,fmの電磁波の位相を前記更新処理部によって更新した後の位相とを直線近似する近似部と、
この近似部によって得られた近似直線の傾きと前記被測定物の厚さLとから、前記被測定物の比誘電率を算出する比誘電率算出部とから構成されることを特徴とする誘電率測定システム。 A transmitter that irradiates an object to be measured with electromagnetic waves of frequencies f 1 , f 2 , ..., F m of m (m is an integer of 3 or more).
It is equipped with a receiver that detects electromagnetic waves transmitted through the object to be measured and calculates the relative permittivity of the object to be measured.
The transmitter has a maximum dielectric constant of epsilon eff _ max envisaged of the object to be measured, said known thickness of the object to be measured L, when the speed of light is c, the two adjacent frequency f n, The interval f s of f n + 1 (n is an integer greater than or equal to 1 (m-1)) is
The receiver
An antenna that receives electromagnetic waves of m frequencies f 1 , f 2 , ..., F m that have passed through the object to be measured, and
A phase measuring unit that measures the phase of each of the m electromagnetic waves of frequencies f 1 , f 2 , ..., F m received by this antenna, and
A phase difference calculation unit that calculates the phase difference between two adjacent electromagnetic waves of frequencies f n and f n + 1 based on the measurement results of this phase measurement unit.
When the phase difference calculated by the phase difference calculation unit is negative, the process of adding 2π to each of the phases of the electromagnetic waves of each frequency after f n + 1 and updating is performed from n = 1 to n = m-1. Update processing unit that repeats up to
The phase of the electromagnetic wave of the lowest frequency f 1 of m frequencies f 1 , f 2 , ..., F m , and m-1 frequencies f 2 , ..., f m excluding f 1 . An approximation unit that linearly approximates the phase of the electromagnetic wave after it has been updated by the update processing unit, and
A dielectric characterized by being composed of a relative permittivity calculation unit that calculates the relative permittivity of the object to be measured from the slope of the approximate straight line obtained by the approximate unit and the thickness L of the object to be measured. Permittivity measurement system.
前記位相測定部は、前記送信機と前記受信機のアンテナとの間に背景物質のみがあって前記被測定物がない状態と、前記背景物質と前記被測定物とがある状態のそれぞれで1回ずつ前記位相の測定を行い、
前記位相差算出部は、前記背景物質のみがあって前記被測定物がない状態で測定された電磁波の位相と前記背景物質と前記被測定物とがある状態で測定された電磁波の位相との差である位相変化を周波数毎に算出し、隣接する2つの周波数fn,fn+1の電磁波の位相変化θnとθn+1との差を、これら周波数fn,fn+1の電磁波の位相差とし、
前記更新処理部は、前記位相差算出部によって算出された位相差が負の場合にfn+1以降の各周波数の電磁波の位相変化θn+1,θn+2,・・・,θmのそれぞれに2πを加算して更新する処理を、n=1からn=m−1まで繰り返し、
前記近似部は、m個の周波数f1,f2,・・・,fmのうちの最低の周波数f1の電磁波の位相変化θ1と、f1を除くm−1個の周波数f2,・・・,fmの電磁波の位相θ2,・・・,θmを前記更新処理部によって更新した後の位相変化φ2,・・・,φmとを直線近似することを特徴とする誘電率測定システム。 In the dielectric constant measuring system according to claim 1,
The phase measuring unit is 1 in each of a state where there is only a background material between the transmitter and the antenna of the receiver and there is no object to be measured, and there is a background material and the object to be measured. The phase is measured one time at a time.
The phase difference calculation unit determines the phase of the electromagnetic wave measured in the state where there is only the background material and the object to be measured, and the phase of the electromagnetic wave measured in the state where the background material and the object to be measured are present. The phase change, which is the difference, is calculated for each frequency, and the difference between the phase changes θ n and θ n + 1 of the electromagnetic waves of two adjacent frequencies f n , f n + 1 is calculated by these frequencies f n , f n + 1. The phase difference of the electromagnetic waves of
When the phase difference calculated by the phase difference calculation unit is negative, the update processing unit changes the phase of the electromagnetic wave of each frequency after f n + 1, θ n + 1 , θ n + 2 , ..., θ. The process of adding 2π to each of m and updating is repeated from n = 1 to n = m-1.
The approximation part is the phase change θ 1 of the electromagnetic wave of the lowest frequency f 1 among m frequencies f 1 , f 2 , ..., F m , and m-1 frequencies f 2 excluding f 1. a feature., phase theta 2 of the electromagnetic wave of f m, ..., theta phase change after the m updated by the update processing unit phi 2, ..., to linear approximation and phi m Dielectric constant measurement system.
このアンテナで受信されたm個の周波数f1,f2,・・・,fmの電磁波のそれぞれの位相を測定する位相測定部と、
この位相測定部の測定結果を基に隣接する2つの周波数fn,fn+1(nは1以上(m−1)以下の整数)の電磁波の位相差を算出する位相差算出部と、
この位相差算出部によって算出された位相差が負の場合にfn+1以降の各周波数の電磁波の位相のそれぞれに2πを加算して更新する処理を、n=1からn=m−1まで繰り返す更新処理部と、
m個の周波数f1,f2,・・・,fmのうちの最低の周波数f1の電磁波の位相と、f1を除くm−1個の周波数f2,・・・,fmの電磁波の位相を前記更新処理部によって更新した後の位相とを直線近似する近似部と、
この近似部によって得られた近似直線の傾きと前記被測定物の既知の厚さLとから、前記被測定物の比誘電率を算出する比誘電率算出部とを備え、
前記m個の周波数f1,f2,・・・,fmの電磁波は、前記被測定物の想定される最大比誘電率をεeff_max、光速をcとしたとき、隣接する2つの周波数fn,fn+1の間隔fsが
A phase measuring unit that measures the phase of each of the m electromagnetic waves of frequencies f 1 , f 2 , ..., F m received by this antenna, and
A phase difference calculation unit that calculates the phase difference of electromagnetic waves of two adjacent frequencies f n and f n + 1 (n is an integer of 1 or more (m-1) or less) based on the measurement result of this phase measurement unit.
When the phase difference calculated by the phase difference calculation unit is negative, the process of adding 2π to each of the phases of the electromagnetic waves of each frequency after f n + 1 and updating is performed from n = 1 to n = m-1. Update processing unit that repeats up to
The phase of the electromagnetic wave of the lowest frequency f 1 of m frequencies f 1 , f 2 , ..., F m , and m-1 frequencies f 2 , ..., f m excluding f 1 . An approximation unit that linearly approximates the phase of the electromagnetic wave after it has been updated by the update processing unit, and
A relative permittivity calculation unit for calculating the relative permittivity of the object to be measured is provided from the slope of the approximate straight line obtained by the approximate section and the known thickness L of the object to be measured.
The electromagnetic waves of the m frequencies f 1 , f 2 , ..., F m are two adjacent ones when the assumed maximum relative permittivity of the object to be measured is ε eff _ max and the speed of light is c. The interval f s between the frequencies f n and f n + 1
前記位相測定部は、前記電磁波の到来方向に背景物質のみがあって前記被測定物がない状態と、前記背景物質と前記被測定物とがある状態のそれぞれで1回ずつ前記位相の測定を行い、
前記位相差算出部は、前記背景物質のみがあって前記被測定物がない状態で測定された電磁波の位相と前記背景物質と前記被測定物とがある状態で測定された電磁波の位相との差である位相変化を周波数毎に算出し、隣接する2つの周波数fn,fn+1の電磁波の位相変化θnとθn+1との差を、これら周波数fn,fn+1の電磁波の位相差とし、
前記更新処理部は、前記位相差算出部によって算出された位相差が負の場合にfn+1以降の各周波数の電磁波の位相変化θn+1,θn+2,・・・,θmのそれぞれに2πを加算して更新する処理を、n=1からn=m−1まで繰り返し、
前記近似部は、m個の周波数f1,f2,・・・,fmのうちの最低の周波数f1の電磁波の位相変化θ1と、f1を除くm−1個の周波数f2,・・・,fmの電磁波の位相θ2,・・・,θmを前記更新処理部によって更新した後の位相変化φ2,・・・,φmとを直線近似することを特徴とする誘電率測定装置。 In the dielectric constant measuring apparatus according to claim 3,
The phase measuring unit measures the phase once in each of a state where there is only a background substance in the direction of arrival of the electromagnetic wave and there is no object to be measured and a state where the background substance and the object to be measured are present. Do,
The phase difference calculation unit determines the phase of the electromagnetic wave measured in the state where there is only the background material and the object to be measured, and the phase of the electromagnetic wave measured in the state where the background material and the object to be measured are present. The phase change, which is the difference, is calculated for each frequency, and the difference between the phase changes θ n and θ n + 1 of the electromagnetic waves of two adjacent frequencies f n , f n + 1 is calculated by these frequencies f n , f n + 1. The phase difference of the electromagnetic waves of
When the phase difference calculated by the phase difference calculation unit is negative, the update processing unit changes the phase of the electromagnetic wave of each frequency after f n + 1, θ n + 1 , θ n + 2 , ..., θ. The process of adding 2π to each of m and updating is repeated from n = 1 to n = m-1.
The approximation part is the phase change θ 1 of the electromagnetic wave of the lowest frequency f 1 among m frequencies f 1 , f 2 , ..., F m , and m-1 frequencies f 2 excluding f 1. a feature., phase theta 2 of the electromagnetic wave of f m, ..., theta phase change after the m updated by the update processing unit phi 2, ..., to linear approximation and phi m Dielectric constant measuring device.
前記被測定物を透過したm個の周波数f1,f2,・・・,fmの電磁波を受信する第2のステップと、
この第2のステップで受信したm個の周波数f1,f2,・・・,fmの電磁波のそれぞれの位相を測定する第3のステップと、
この第3のステップの測定結果を基に隣接する2つの周波数fn,fn+1の電磁波の位相差を算出する第4のステップと、
この第4のステップで算出した位相差が負の場合にfn+1以降の各周波数の電磁波の位相のそれぞれに2πを加算して更新する処理を、n=1からn=m−1まで繰り返す第5のステップと、
m個の周波数f1,f2,・・・,fmのうちの最低の周波数f1の電磁波の位相と、f1を除くm−1個の周波数f2,・・・,fmの電磁波の位相を前記第5のステップによって更新した後の位相とを直線近似する第6のステップと、
この第6のステップによって得られた近似直線の傾きと前記被測定物の厚さLとから、前記被測定物の比誘電率を算出する第7のステップとを含むことを特徴とする誘電率測定方法。 When the assumed maximum relative permittivity of the object to be measured is ε eff _ max , the known thickness of the object to be measured is L, and the speed of light is c, the interval between two adjacent frequencies f n and f n + 1 . f s
The second step of receiving electromagnetic waves of m frequencies f 1 , f 2 , ..., F m transmitted through the object to be measured, and
The third step of measuring the phases of the electromagnetic waves of m frequencies f 1 , f 2 , ..., And f m received in this second step, and
Based on the measurement results of this third step, the fourth step of calculating the phase difference between the electromagnetic waves of two adjacent frequencies f n and f n + 1 and
When the phase difference calculated in the fourth step is negative, the process of adding 2π to each of the phases of the electromagnetic waves of each frequency after f n + 1 and updating is performed from n = 1 to n = m-1. The fifth step to repeat and
The phase of the electromagnetic wave of the lowest frequency f 1 of m frequencies f 1 , f 2 , ..., F m , and m-1 frequencies f 2 , ..., f m excluding f 1 . A sixth step of linearly approximating the phase of the electromagnetic wave after updating the phase in the fifth step, and
The permittivity includes a seventh step of calculating the relative permittivity of the object to be measured from the slope of the approximate straight line obtained by the sixth step and the thickness L of the object to be measured. Measuring method.
背景物質のみがあって前記被測定物がない状態と、前記背景物質と前記被測定物とがある状態のそれぞれで1回ずつ前記第3のステップを行い、
前記第4のステップは、前記背景物質のみがあって前記被測定物がない状態で測定された電磁波の位相と前記背景物質と前記被測定物とがある状態で測定された電磁波の位相との差である位相変化を周波数毎に算出し、隣接する2つの周波数fn,fn+1の電磁波の位相変化θnとθn+1との差を、これら周波数fn,fn+1の電磁波の位相差とするステップを含み、
前記第5のステップは、前記第4のステップで算出した位相差が負の場合にfn+1以降の各周波数の電磁波の位相変化θn+1,θn+2,・・・,θmのそれぞれに2πを加算して更新する処理を、n=1からn=m−1まで繰り返すステップを含み、
前記第6のステップは、m個の周波数f1,f2,・・・,fmのうちの最低の周波数f1の電磁波の位相変化θ1と、f1を除くm−1個の周波数f2,・・・,fmの電磁波の位相θ2,・・・,θmを前記第5のステップによって更新した後の位相変化φ2,・・・,φmとを直線近似するステップを含むことを特徴とする誘電率測定方法。 In the dielectric constant measuring method according to claim 5,
The third step is performed once for each of the state where there is only the background substance and there is no object to be measured and the state where there is the background substance and the object to be measured.
In the fourth step, the phase of the electromagnetic wave measured with only the background material and the object to be measured and the phase of the electromagnetic wave measured with the background material and the object to be measured are set. The phase change, which is the difference, is calculated for each frequency, and the difference between the phase changes θ n and θ n + 1 of the electromagnetic waves of two adjacent frequencies f n , f n + 1 is calculated by these frequencies f n , f n + 1. Including the step of making the phase difference of the electromagnetic wave of
In the fifth step, when the phase difference calculated in the fourth step is negative, the phase change of the electromagnetic wave of each frequency after f n + 1 is θ n + 1 , θ n + 2 , ..., θ. The process of adding 2π to each of m and updating it includes a step of repeating from n = 1 to n = m-1.
In the sixth step, the phase change θ 1 of the electromagnetic wave having the lowest frequency f 1 among m frequencies f 1 , f 2 , ..., F m , and m-1 frequencies excluding f 1 step f 2, ···, phase theta 2 of the electromagnetic wave of f m, ···, phase change after updating theta m by the fifth step φ 2, ···, linear approximation and phi m A method for measuring a dielectric constant, which comprises.
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JP4006525B2 (en) * | 2003-11-20 | 2007-11-14 | 独立行政法人産業技術総合研究所 | Sample flatness and complex permittivity measurement device and measurement method by light transmission measurement |
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