JP2008076239A - Electromagnetic wave physical quantity measuring instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic wave physical quantity measuring instrument capable of easily, inexpensively and simply performing the manufacture and assembling of an antenna. <P>SOLUTION: In the electromagnetic wave physical quantity measuring instrument constituted so that transmission and detection antennae are arranged in opposed relationship in a form holding piping or a container for allowing a substance to be measured containing a measuring target to flow and the difference between propagation times or phase delays is operated by comparing the first propagation time or first phase delay of the electromagnetic wave thrown into the substance to be measured to be detected with the second propagation time or second phase delay of the electromagnetic wave thrown into the substance to be measured to be detected to measure the physical quantity of the measuring target present in the substance to be measured, at least one of the transmission and detection antennae is set to a reverse F antenna having a linear radiation conductor 10a having a length of the 1/2 wavelength of the electromagnetic wave, the earth conductor 20a arranged in opposed relation to the radiation conductor 10a so as to leave the interval of the 1/4 wavelength of the electromagnetic wave, a shortcircuit part 12a for connecting the radiation conductor 10a and the earth conductor 20a and a power supply part 14a for supplying power to the radiation conductor 10a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electromagnetic wave physical quantity measuring apparatus for measuring a physical quantity of a measurement target contained in various suspended substances and soluble substances, which are substances to be measured, using electromagnetic waves, and in particular, by making an antenna easy to manufacture. The present invention relates to an electromagnetic physical quantity measuring apparatus having an antenna that is less expensive than the conventional one.

  Conventionally, to measure the concentration of suspended substances in liquids, an ultrasonic densitometer that determines the concentration by measuring the attenuation rate of ultrasonic waves, and the transmitted light attenuation rate or scattered light increase rate using light An optical densitometer that obtains a concentration by measurement is often used.

  However, in the case of an ultrasonic densitometer, if bubbles are mixed into the liquid, the measurement error increases due to the large influence. Further, in the case of an optical densitometer, if dirt or the like adheres to the light incident or light receiving optical window, the measurement error becomes large due to the influence. Therefore, recently, a microwave concentration measuring device has been considered as a concentration meter that is not easily affected by bubbles in these liquids and dirt on the optical window, and has come into practical use.

  FIG. 7 shows a schematic configuration of such a microwave densitometer. On the side wall of the pipe 1 through which the liquid to be measured passes, the microwave transmitting antenna 2 and the microwave receiving antenna 3 are arranged to face each other. The microwave oscillator 4 inputs the microwave to the microwave transmission antenna 2 via the power splitter 5. The microwave transmitting antenna 2 transmits a microwave to propagate the liquid to be measured in the pipe 1. The microwave receiving antenna 3 receives the transmitted microwave and inputs it to the phase difference measuring circuit 6. On the other hand, the microwave oscillator 4 inputs the microwave directly to the phase difference measurement circuit 6 via the power splitter 5.

  The phase difference measuring circuit 6 obtains the phase delay θ2 of the microwave propagating through the liquid to be measured in the pipe 1 with respect to the microwave directly received from the microwave oscillator 4 through the power splitter 5. Further, the phase delay θ2 and the phase when the pipe 1 is previously filled with a reference liquid (for example, tap water that can be regarded as having a zero concentration) and the microwave propagating through the reference liquid in the same state as the liquid to be measured are measured. The delay θ1 is compared, and the concentration X of the liquid to be measured is obtained from the phase difference Δθ = (θ2−θ1) using a calibration curve as shown in FIG. Specifically, the concentration X is obtained based on a calibration curve X = aΔθ + b corresponding to each type of liquid to be measured. Here, a is the slope of the calibration curve, b is the intercept of the calibration curve, and normally b = 0.

  Patent Document 1 is obtained by arranging a microwave transmission system and a reception system in a detection tube or a detection container and propagating the microwave into a reference fluid in the detection tube or the detection container. The phase difference between the first phase lag and the second phase lag obtained by propagating the microwave in the fluid to be measured including the substance to be measured in the detection tube or in the detection container is calculated. The invention relates to a concentration meter that obtains and measures the concentration of a fluid to be measured from the phase difference.

  The present invention shows a specific configuration of the densitometer. First, an opening window for microwave transmission and reception is formed at positions facing each other across the tube axis of the detection tube or the detection container, and an antenna is attached to the opening window via an airtight seal packing A board is provided. Further, the transmitting antenna and the receiving antenna are individually attached to the antenna mounting plate, and the microwave transmitting system and the receiving system are configured by filling the openings of the transmitting antenna and the receiving antenna with a dielectric. . The microwave transmission system and the reception system obtain a first phase lag and a second phase lag using a microwave having a frequency range of 1.7 GHz to 2.0 GHz as a microwave, and determine the position from each phase lag. Measure the phase difference.

FIG. 9 is a diagram illustrating a configuration of a transmission antenna or a reception antenna. Both the transmitting antenna and the receiving antenna use the coaxial waveguide converter 7 and have a configuration in which a dielectric 8 having a dielectric constant of about 20 is inserted therein in order to adjust the resonance frequency. By adopting a configuration in which the dielectric 8 is filled, the antenna can be miniaturized and impedance matching can be easily performed.
Japanese Patent Laid-Open No. 11-83758

  However, the coaxial waveguide converter 7 constituting the antenna shown in FIG. 9 and the high dielectric constant dielectric 8 filled therein are very expensive. In addition, there is a problem that it takes time to assemble both.

  The present invention solves the above-mentioned problems of the prior art. An electromagnetic physical quantity measuring device that can be manufactured easily and inexpensively and can be easily assembled by configuring the antenna with a linear antenna or a patch antenna. The issue is to provide.

  In order to solve the above-described problems, an electromagnetic wave physical quantity measuring apparatus according to the present invention is characterized in that the transmission side antenna and the reception side antenna are sandwiched between a pipe or a container through which a substance to be measured including a measurement target flows. The first propagation time or the first phase lag of the electromagnetic wave received by the receiving antenna, and the fluid serving as a reference from the transmitting antenna, which are arranged to face each other, enter the electromagnetic wave from the transmitting antenna into the substance to be measured. An electromagnetic wave is incident on the inside, and the difference between the propagation time or the phase delay is calculated by comparing the second propagation time or the second phase delay of the electromagnetic wave received by the receiving antenna, and is present in the measured substance. In the electromagnetic wave physical quantity measuring device that measures the physical quantity of the measurement target, at least one of the transmitting antenna and the receiving antenna has a length of a half wavelength of the electromagnetic wave. A linear radiating conductor, a grounding conductor disposed opposite to the radiating conductor with an interval of a quarter wavelength of the electromagnetic wave, and a short-circuit means for connecting the radiating conductor and the grounding conductor; It is an inverted F antenna which has a feeding means for feeding the radiation conductor.

前記誘電体の他方の表面に配置された接地導体と、前記放射導体と前記接地導体とを接続する短絡手段と、前記放射導体を給電する給電手段とを有する逆Ｆアンテナであることを特徴とする。 According to the second aspect of the present invention, a transmitting antenna and a receiving antenna are arranged opposite to each other so as to sandwich a pipe or container through which a substance to be measured including a measurement target is sandwiched, and electromagnetic waves are incident from the transmitting antenna into the substance to be measured. The first propagation time or the first phase delay of the electromagnetic wave received by the receiving antenna and the electromagnetic wave incident on the reference fluid from the transmitting antenna and the first electromagnetic wave received by the receiving antenna. In the electromagnetic wave physical quantity measuring apparatus for measuring the physical quantity of the measurement target existing in the substance to be measured by calculating a difference between the propagation time or the phase delay by comparing the two propagation times or the second phase delay, There are few antennas and the receiving antenna.

It is an inverted-F antenna having a ground conductor disposed on the other surface of the dielectric, a short-circuit means for connecting the radiation conductor and the ground conductor, and a power supply means for feeding the radiation conductor. To do.

方形の放射導体と、前記誘電体の他方の表面に配置された接地導体と、前記放射導体を給電する第１給電部とを有する正方形パッチアンテナであることを特徴とする。 According to a third aspect of the present invention, a transmitting antenna and a receiving antenna are arranged opposite to each other so as to sandwich a pipe or a container through which a substance to be measured including a measurement target flows, and an electromagnetic wave is incident from the transmitting antenna into the substance to be measured. The first propagation time or the first phase delay of the electromagnetic wave received by the receiving antenna and the electromagnetic wave incident on the reference fluid from the transmitting antenna and the first electromagnetic wave received by the receiving antenna. In the electromagnetic wave physical quantity measuring apparatus for measuring the physical quantity of the measurement object existing in the substance to be measured by calculating a difference between the propagation time or the phase delay by comparing the two propagation times or the second phase delay, There are few antennas and the receiving antenna.

It is a square patch antenna having a rectangular radiating conductor, a ground conductor disposed on the other surface of the dielectric, and a first feeding portion that feeds the radiating conductor.

導体と、前記誘電体の他方の表面に配置された接地導体と、前記放射導体を給電する第１給電部とを有する円形パッチアンテナであることを特徴とする。 According to a fourth aspect of the present invention, a transmitting antenna and a receiving antenna are arranged opposite to each other so as to sandwich a pipe or a container through which a substance to be measured including a measurement target is sandwiched, and electromagnetic waves are incident from the transmitting antenna into the substance to be measured. The first propagation time or the first phase delay of the electromagnetic wave received by the receiving antenna and the electromagnetic wave incident on the reference fluid from the transmitting antenna and the first electromagnetic wave received by the receiving antenna. In the electromagnetic wave physical quantity measuring apparatus for measuring the physical quantity of the measurement target existing in the substance to be measured by calculating a difference between the propagation time or the phase delay by comparing the two propagation times or the second phase delay, There are few antennas and the receiving antenna.

It is a circular patch antenna having a conductor, a grounding conductor disposed on the other surface of the dielectric, and a first feeding portion that feeds the radiation conductor.

  According to a fifth aspect of the present invention, in the third or fourth aspect, the second power feeding unit that feeds power to a position different from the first power feeding unit on the square radiation conductor or the circular radiation conductor, and the first power feeding. And a phase shifter that adjusts the phase of at least one of the second power feeding unit, and the power feeding point of the first power feeding unit and the power feeding point of the second power feeding unit on the radiation conductor are both radiated. It is equidistant from the center on the conductor, and straight lines connecting each feeding point and the center intersect each other at right angles or substantially right angles, and the phase shifter shifts the signal phase at each feeding point by 90 degrees from each other. To do.

  In a sixth aspect of the present invention, a transmitting antenna and a receiving antenna are arranged opposite to each other so as to sandwich a pipe or a container through which a substance to be measured including a measurement target is sandwiched, and electromagnetic waves are incident on the substance to be measured from the transmitting antenna. The first propagation time or the first phase delay of the electromagnetic wave received by the receiving antenna and the electromagnetic wave incident on the reference fluid from the transmitting antenna and the first electromagnetic wave received by the receiving antenna. In the electromagnetic wave physical quantity measuring apparatus for measuring the physical quantity of the measurement target existing in the substance to be measured by calculating a difference between the propagation time or the phase delay by comparing the two propagation times or the second phase delay, At least one of the antenna and the receiving antenna is spirally wound, and when the wavelength of the electromagnetic wave is λ, the length of the spiral axis is λ / 4 or less and the diameter of the spiral is λ / π A spiral radiating conductors, wherein the a helical antenna having a helical axis and vertically disposed ground conductor of the radiating conductor.

  A seventh aspect of the invention is characterized in that, in any one of the first to sixth aspects, the surface shape of the ground conductor includes a projected shape of the radiation conductor on the ground conductor.

  According to the invention described in claim 1 of the present invention, since it can be composed of only a linear metal, it is easy to manufacture and inexpensive, and can be easily assembled.

  According to the invention described in claims 2 to 4 of the present invention, in addition to the effect of the invention described in claim 1, the use of the patch antenna greatly reduces the cost. In addition, by using a dielectric having a large relative dielectric constant, a thin antenna can be formed.

  According to the fifth aspect of the present invention, since the electromagnetic waves to be transmitted and received are circularly polarized waves, the reflected waves from the water surface are reversely rotated circularly even when the inside of the pipe is not full. Since it is not received as a wave, the error factor is reduced and an accurate measurement can be performed.

  According to the invention described in claim 6 of the present invention, since it can be composed only of a linear metal, it is easy to manufacture and inexpensive, and the electromagnetic wave transmitted and received is circularly polarized. As with the invention, accurate measurements can be made.

  Embodiments of an electromagnetic wave physical quantity measuring apparatus according to the present invention will be described below in detail with reference to the drawings.

  Embodiments of the present invention will be described below with reference to the drawings. 1 is a diagram illustrating a configuration of an antenna of an electromagnetic wave physical quantity measuring apparatus according to a first embodiment of the present invention.

  First, the configuration of the present embodiment will be described. The electromagnetic wave physical quantity measuring apparatus according to the present embodiment is the same as the conventional configuration shown in FIG. 7 as a whole. A transmitting antenna 2 and a receiving antenna 3 are arranged opposite each other so as to sandwich a pipe 1 through which a substance to be measured including a measuring object is sandwiched, and an electromagnetic wave is incident on the measuring substance from the transmitting antenna 2 and is received by the receiving antenna 3. The first propagation time or the first phase delay of the received electromagnetic wave, and the second propagation time or the second phase delay of the electromagnetic wave incident on the reference fluid from the transmitting antenna 2 and received by the receiving antenna 3 And the difference in propagation time or phase delay is calculated, and the physical quantity of the measurement target existing in the substance to be measured is measured.

  In the present embodiment, the configuration of the transmitting antenna 2 and the receiving antenna 3 includes a radiating conductor 10a, a short-circuit portion 12a, a power feeding portion 14a, and a ground conductor 20a as shown in FIG.

  The radiation conductor 10a has a length of a half wavelength of an electromagnetic wave having a desired frequency. Examples of the material of the radiation conductor 10a include metals such as silver, gold, and copper having high conductivity. The short-circuit portion 12a corresponds to the short-circuit means of the present invention, and connects the radiation conductor 10a and the ground conductor 20a. The power feeding unit 14a corresponds to the power feeding means of the present invention, is connected to the microwave oscillator 4, and feeds the radiation conductor 10a. The ground conductor 20a is disposed opposite to the radiation conductor 10a with an interval of a quarter wavelength of the electromagnetic wave having a desired frequency.

  For example, when a coaxial cable is used for the power feeding part 14a, the shield wire of the coaxial cable is connected to the ground conductor 20a, and the power feed line penetrates the ground conductor 20a in a non-contact state with the ground conductor 20a to the radiation conductor 10a. It is connected.

  The short circuit part 12a is connected to the end part of the radiation conductor 10a at a right angle. The power feeding part 14a is connected in the middle of the radiation conductor 10a substantially parallel to the short circuit part 12a. Therefore, this antenna is an inverted F-shaped inverted F antenna as a whole.

  The surface shape of the ground conductor 20a includes the projected shape of the radiation conductor 10a on the ground conductor 20a. In FIG. 1, the ground conductor 20a is drawn in a circular shape, but any projection shape of the radiation conductor 10a, that is, any shape that includes a straight line having a length of a half wavelength is applicable. good.

  Next, the operation of the present embodiment configured as described above will be described. Since the operation of the entire electromagnetic wave physical quantity measuring apparatus is the same as that of the prior art described with reference to FIG. Instead of using the coaxial waveguide converter as shown in FIG. 9 as the transmitting side antenna and the receiving side antenna, the above-described inverted F antenna is used. The inverted-F antenna is provided with a short-circuit portion near the feeding point in order to facilitate impedance matching of an inverted L-type antenna obtained by bending a monopole antenna in the middle to lower the posture.

  The microwave oscillator 4 supplies power to the radiation conductor 10a through the power supply unit 14a. As a result, electromagnetic waves are incident on the substance to be measured in the pipe. Since the length of the short-circuit portion 12a, that is, the length between the radiating conductor 10a and the ground conductor 20a is a quarter wavelength, the electromagnetic wave is accurately transmitted toward the pipe.

  As described above, according to the electromagnetic wave physical quantity measuring device according to the first embodiment of the present invention, the transmission-side antenna 2 or the reception-side antenna 3 shown in FIG. Compared to a conventional antenna using such a coaxial waveguide converter, the cost is low and a significant cost reduction can be realized. In addition, there is an advantage that it is easy to manufacture and does not require assembling.

  Furthermore, by setting the length between the radiating conductor 10a and the ground conductor 20a to a quarter wavelength, the electromagnetic wave is accurately transmitted toward the substance to be measured in the pipe. Further, since the surface shape of the ground conductor 20a has a size including the projected shape of the radiation conductor 10a with respect to the ground conductor 20a, good directivity characteristics can be obtained.

  In addition, when radiating electromagnetic waves, so-called matching is required to match the electrical impedance with the radiation destination. As a characteristic of the inverted F antenna, it is possible to adjust the impedance by changing the position of the feeding point on the radiation conductor 10a. it can.

  FIG. 2 is a diagram illustrating the configuration of the antenna of the electromagnetic wave physical quantity measuring apparatus according to the second embodiment of the present invention. First, the configuration of the present embodiment will be described. The electromagnetic wave physical quantity measuring apparatus according to the present embodiment is the same as that of the first embodiment in that it is not different from the conventional configuration shown in FIG.

  In this embodiment, as shown in FIG. 2, the transmitting antenna 2 and the receiving antenna 3 are configured by a radiating conductor 10b, a short-circuit portion 12b, a power feeding portion 14b, a ground conductor 20b, and a dielectric 30a.

短絡部１２ｂは、本発明の短絡手段に対応し、誘電体３０ａを貫通して放射導体１０ｂと接地導体２０ｂとを接続する。

The short-circuit portion 12b corresponds to the short-circuit means of the present invention, and connects the radiation conductor 10b and the ground conductor 20b through the dielectric 30a.

  The power feeding unit 14b penetrates the dielectric 30a from a minute portion from which a part of the ground conductor 20b is peeled off, connects the radiation conductor 10b and the microwave oscillator 4, and feeds the radiation conductor 10b. The power feeding portion 14b is not in contact with the ground conductor 20b.

  That is, the configuration is the same as that of the first embodiment except that the dielectric 30a is added and the length of the radiation conductor 10b and the length between the radiation conductor 10b and the ground conductor 20b are different.

  Next, the operation of the present embodiment configured as described above is substantially the same as that of the first embodiment. The above-described patch antenna is used as the transmitting antenna and the receiving antenna.

  As described above, according to the electromagnetic wave physical quantity measuring device according to the second embodiment of the present invention, the transmission-side antenna 2 or the reception-side antenna 3 shown in FIG. 7 can be configured by a process such as etching based on the high-frequency circuit board. At the same time, it can be manufactured in large quantities at low cost by printing technology.

  Furthermore, since the wavelength shortening rate in the dielectric is the reciprocal of the square root of the effective relative permittivity, the thickness of the dielectric 30a and the length of the radiation conductor 10b are increased by increasing the relative permittivity of the dielectric 30a. Thus, the antenna can be reduced in size.

  In addition, the same effects as those of the first embodiment can be obtained.

  FIG. 3 is a diagram illustrating the configuration of the antenna of the electromagnetic wave physical quantity measuring apparatus according to the third embodiment of the present invention. First, the configuration of the present embodiment will be described. The electromagnetic wave physical quantity measuring apparatus according to the present embodiment is the same as that of the first embodiment in that it is not different from the conventional configuration shown in FIG.

  In this embodiment, the configuration of the transmitting antenna 2 and the receiving antenna 3 includes a radiating conductor 40a, a power feeding portion 14c, a ground conductor 20c, and a dielectric 30b as shown in FIG.

給電部１４ｃは、本発明の第１給電部に対応し、接地導体２０ｃの一部をはがした微少部分から誘電体３０ｂを貫通して放射導体４０ａとマイクロ波発振器４とを接続するとともに、放射導体４０ａを給電する。この給電部１４ｃは、接地導体２０ｃには非接触である。

The power feeding unit 14c corresponds to the first power feeding unit of the present invention, and connects the radiation conductor 40a and the microwave oscillator 4 through the dielectric 30b from a minute portion where a part of the ground conductor 20c is peeled off, Power is supplied to the radiation conductor 40a. The power feeding portion 14c is not in contact with the ground conductor 20c.

  The surface shape of the ground conductor 20c includes the projection shape of the radiating conductor 40b on the ground conductor 20c, as in the first embodiment, but has a margin of 0.3λ or more than the outermost portion of the projection shape. The surface shape it has is ideal.

  Next, the operation of the present embodiment configured as described above is substantially the same as that of the second embodiment. The square patch antenna described above is used as the transmitting antenna and the receiving antenna.

  As described above, according to the electromagnetic physical quantity measuring device according to the embodiment 3 of the present invention, the same effect as that of the electromagnetic physical quantity measuring device of the second embodiment can be obtained.

  FIG. 4 is a diagram illustrating the configuration of the antenna of the electromagnetic wave physical quantity measuring apparatus according to the fourth embodiment of the present invention. First, the configuration of the present embodiment will be described. The difference from the third embodiment is that the shape of the radiation conductor 40b is not square but circular.

  In this embodiment, the configuration of the transmitting antenna 2 and the receiving antenna 3 includes a radiating conductor 40b, a feeding portion 14d, a grounding conductor 20d, and a dielectric 30c as shown in FIG.

その他の構成は、実施例３と同じであるため、説明を省略する。

Other configurations are the same as those of the third embodiment, and thus the description thereof is omitted.

  Next, the operation of the present embodiment configured as described above is substantially the same as that of the third embodiment. The circular patch antenna described above is used as the transmitting antenna and the receiving antenna.

  As described above, according to the electromagnetic physical quantity measurement device according to Embodiment 4 of the present invention, the same effect as that of the electromagnetic wave physical quantity measurement device according to Embodiment 3 can be obtained. Furthermore, the electromagnetic wave mode by the circular patch antenna is the same as that of the circular waveguide. Moreover, when the opening window of the pipe is circular, the opening window can be regarded as a circular waveguide, so when transmitting electromagnetic waves from the circular patch antenna toward the pipe, the same electromagnetic wave mode is used. Matching is achieved, reflection is small, and transmission can be performed with good propagation efficiency.

  Here, the reason why the opening window portion of the pipe is circular is that there is an advantage that it is easy to process.

  FIG. 5 is a diagram illustrating the configuration of the antenna of the electromagnetic wave physical quantity measuring apparatus according to the fifth embodiment of the present invention. First, the configuration of the present embodiment will be described with reference to FIG. The electromagnetic wave physical quantity measuring apparatus according to the present embodiment is the same as that of the first embodiment in that it is not different from the conventional configuration shown in FIG.

  In the present embodiment, as shown in FIG. 5A, the configuration of the transmitting antenna 2 and the receiving antenna 3 includes a radiating conductor 40c, a first feeding unit 14e, a second feeding unit 14f, a grounding conductor 20e, and a dielectric 30d. , And a phase shifter 50.

  The difference from the third embodiment is that there are two power feeding units. The second power feeding unit 14f feeds power to a position different from the first power feeding unit 14e on the square radiation conductor 40c. The phase shifter 50 adjusts the phase of at least one of the first power feeding unit 14e and the second power feeding unit, and shifts the signal phase at each power feeding point by 90 degrees. Further, both the feeding point of the first feeding part 14e and the feeding point of the second feeding part 14f on the radiation conductor 40c are equidistant from the center on the radiation conductor 40c, and each feeding point and the center on the radiation conductor 40c. Are perpendicular to each other or substantially perpendicular to each other.

  The dimensions and the like are the same as those of the square patch antenna shown in FIG. Other configurations are the same as those of the third embodiment, and thus description thereof is omitted.

  FIG. 5B shows an antenna configuration in which the square radiation conductor 40c of the antenna shown in FIG. 5A is replaced with a circular radiation conductor 40d. The diameter of the radiation conductor 40d and the thickness of the dielectric 30e are the same as those of the circular patch antenna shown in FIG. The difference from the fourth embodiment is that there are two power feeding units, and the relationship is the same as that in FIG. 3 in FIG.

  Next, the operation of the present embodiment configured as described above is substantially the same as that of Example 3 and Example 4, but the radiated electromagnetic wave is circularly polarized. Circular polarization is polarization in which the plane of polarization rotates with time. When receiving electromagnetic waves arriving with circularly polarized waves, a co-polarized antenna whose plane of polarization rotates in the same direction is required, and reception is not possible with a reversely polarized plane of polarization (reversely polarized).

  As described above, according to the electromagnetic physical quantity measurement device according to Embodiment 5 of the present invention, the same effect as that of the electromagnetic wave physical quantity measurement device according to Embodiment 3 can be obtained. Furthermore, since the electromagnetic waves to be transmitted and received are circularly polarized waves, for example, when the inside of the pipe is not full, the reflected wave from the water surface becomes reversely circularly polarized waves and is not received. Therefore, the error factor is reduced and accurate measurement can be performed. In addition, since the reflected wave from the deposition surface by the sediment to be measured and the reflection by the bubbles in the substance to be measured are not received, the same effect is produced.

  Furthermore, by using a circular patch antenna as shown in FIG. 5B, it is possible to transmit electromagnetic waves with high propagation efficiency as in the fourth embodiment.

  FIG. 6 is a diagram illustrating the configuration of the antenna of the electromagnetic wave physical quantity measuring apparatus according to the sixth embodiment of the present invention. First, the configuration of the present embodiment will be described. The electromagnetic wave physical quantity measuring apparatus according to the present embodiment is the same as that of the first embodiment in that it is not different from the conventional configuration shown in FIG.

  In this embodiment, the configuration of the transmitting antenna 2 and the receiving antenna 3 includes a radiating conductor 60, a feeding portion 14i, and a ground conductor 20g as shown in FIG.

  The radiating conductor 60 is made of a metal that is wound in a spiral and has a helical axis length of λ / 4 or less and a helical diameter of λ / π, where λ is the wavelength of electromagnetic waves to be transmitted and received.

  The power feeding unit 14 i penetrates the ground conductor 20 g from a minute portion where a part of the ground conductor 20 g is peeled off, connects the radiation conductor 60 and the microwave oscillator 4, and feeds the radiation conductor 60. The power feeding portion 14i is not in contact with the ground conductor 20g.

  Next, the operation of the present embodiment configured as described above will be described. Since the operation of the entire electromagnetic wave physical quantity measuring apparatus is the same as that of the prior art described with reference to FIG.

  The microwave oscillator 4 supplies power to the radiation conductor 60 via the power supply unit 14i. As a result, electromagnetic waves are incident on the substance to be measured in the pipe. At that time, the helical radiation conductor, which is a helical antenna, radiates circularly polarized electromagnetic waves. By setting the length of the spiral axis to a quarter wavelength or less, the electromagnetic wave is accurately transmitted in the direction of the spiral axis, that is, toward the pipe.

  As described above, according to the electromagnetic wave physical quantity measuring device according to the sixth embodiment of the present invention, the same effect as that of the first embodiment can be obtained because it is composed of only a linear metal. Further, unlike the second to fifth embodiments, a dielectric is not required, so that it can be manufactured at low cost.

  Furthermore, since the electromagnetic waves transmitted and received are circularly polarized waves, the error factor is reduced as in the fifth embodiment, and the measurement can be performed accurately.

  The electromagnetic physical quantity measuring apparatus according to the present invention can be used for an electromagnetic physical quantity measuring apparatus such as a concentration meter capable of measuring a target physical quantity in a liquid flowing in a pipe.

It is a figure which shows the structure of the transmission side antenna of the electromagnetic wave physical quantity measuring device of the form of Example 1 of this invention, and a receiving side antenna. It is a figure which shows the structure of the transmitting side antenna and receiving side antenna of the electromagnetic wave physical quantity measuring device of the form of Example 2 of this invention. It is a figure which shows the structure of the transmission side antenna of the electromagnetic wave physical quantity measuring device of the form of Example 3 of this invention, and a receiving side antenna. It is a figure which shows the structure of the transmission side antenna of the electromagnetic wave physical quantity measuring device of the form of Example 4 of this invention, and a receiving side antenna. It is a figure which shows the structure of the transmission side antenna of the electromagnetic wave physical quantity measuring device of the form of Example 5 of this invention, and a receiving side antenna. It is a figure which shows the structure of the transmitting side antenna and receiving side antenna of the electromagnetic wave physical quantity measuring device of the form of Example 6 of this invention. It is a block diagram which shows the structure of the conventional electromagnetic wave concentration measuring apparatus. It is a figure which shows the relationship between the propagation time or phase delay of electromagnetic waves, and a substance amount. It is a figure which shows the structure of the transmission side antenna of a conventional electromagnetic wave physical quantity measuring device, and a reception side antenna.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Piping 2 Transmission side antenna 3 Reception side antenna 4 Microwave oscillator 5 Power splitter 6 Phase difference measurement circuit 7 Coaxial waveguide converter 8 High dielectric constant dielectric 10a, 10b, 10c Radiation conductor 12a, 12b, Short-circuit part 14a, 14b, 14c, 14d, 14i Power feeding unit 14e, 14g First power feeding unit 14f, 14h Second power feeding unit 20a, 20b, 20c, 20d, 20e, 20f, 20g Grounding conductors 30a, 30b, 30c, 30d, 30e Dielectric 40a , 40b, 40c, 40d Radiation conductor 50 Phase shifter 60 Radiation conductor

Claims (7)

A transmitting antenna and a receiving antenna are arranged opposite each other so as to sandwich a pipe or container through which a substance to be measured including a measurement target is sandwiched, and an electromagnetic wave is incident on the substance to be measured from the transmitting antenna and is received by the receiving antenna. The first propagation time or the first phase delay of the received electromagnetic wave and the second propagation time or the second phase delay of the electromagnetic wave incident on the reference fluid from the transmitting antenna and received by the receiving antenna In the electromagnetic wave physical quantity measuring apparatus for calculating the physical quantity of the measurement object present in the substance to be measured by calculating the difference in propagation time or phase delay in comparison with
At least one of the transmitting antenna and the receiving antenna is
A linear radiation conductor having a length of a half wavelength of the electromagnetic wave;
A grounding conductor disposed opposite to the radiation conductor and spaced by a quarter wavelength of the electromagnetic wave;
Short-circuit means for connecting the radiation conductor and the ground conductor;
An electromagnetic wave physical quantity measuring device comprising an inverted F antenna having a power feeding means for feeding the radiation conductor. A transmitting antenna and a receiving antenna are arranged opposite each other so as to sandwich a pipe or container through which a substance to be measured including a measurement target is sandwiched, and an electromagnetic wave is incident on the substance to be measured from the transmitting antenna and is received by the receiving antenna. The first propagation time or the first phase delay of the received electromagnetic wave and the second propagation time or the second phase delay of the electromagnetic wave incident on the reference fluid from the transmitting antenna and received by the receiving antenna In the electromagnetic wave physical quantity measuring apparatus for calculating the physical quantity of the measurement object present in the substance to be measured by calculating the difference in propagation time or phase delay in comparison with

A ground conductor disposed on the other surface of the dielectric;
Short-circuit means for connecting the radiation conductor and the ground conductor;
An electromagnetic wave physical quantity measuring device comprising an inverted F antenna having a power feeding means for feeding the radiation conductor. A transmitting antenna and a receiving antenna are arranged opposite each other so as to sandwich a pipe or container through which a substance to be measured including a measurement target is sandwiched, and an electromagnetic wave is incident on the substance to be measured from the transmitting antenna and is received by the receiving antenna. The first propagation time or the first phase delay of the received electromagnetic wave and the second propagation time or the second phase delay of the electromagnetic wave incident on the reference fluid from the transmitting antenna and received by the receiving antenna In the electromagnetic wave physical quantity measuring apparatus for calculating the physical quantity of the measurement object present in the substance to be measured by calculating the difference in propagation time or phase delay in comparison with

A ground conductor disposed on the other surface of the dielectric;
An electromagnetic wave physical quantity measuring apparatus, comprising: a square patch antenna having a first power feeding unit that feeds the radiation conductor. A transmitting antenna and a receiving antenna are arranged opposite each other so as to sandwich a pipe or container through which a substance to be measured including a measurement target is sandwiched, and an electromagnetic wave is incident on the substance to be measured from the transmitting antenna and is received by the receiving antenna. The first propagation time or the first phase delay of the received electromagnetic wave and the second propagation time or the second phase delay of the electromagnetic wave incident on the reference fluid from the transmitting antenna and received by the receiving antenna In the electromagnetic wave physical quantity measuring apparatus for calculating the physical quantity of the measurement object present in the substance to be measured by calculating the difference in propagation time or phase delay in comparison with

A ground conductor disposed on the other surface of the dielectric;
An electromagnetic wave physical quantity measuring apparatus, comprising: a circular patch antenna having a first power feeding unit that feeds the radiation conductor. A second power feeding part for feeding power to a position different from the first power feeding part on the square radiation conductor or the circular radiation conductor;
A phase shifter for adjusting a phase of at least one of the first power feeding unit and the second power feeding unit;
Both the feeding point of the first feeding part and the feeding point of the second feeding part on the radiation conductor are equidistant from the center on the radiation conductor, and straight lines connecting the feeding point and the center are mutually connected. Intersect at right angles or almost right angles,
The electromagnetic wave physical quantity measuring device according to claim 3 or 4, wherein the phase shifter shifts the signal phase at each feeding point by 90 degrees from each other. A transmitting antenna and a receiving antenna are arranged opposite each other so as to sandwich a pipe or container through which a substance to be measured including a measurement target is sandwiched, and an electromagnetic wave is incident on the substance to be measured from the transmitting antenna and is received by the receiving antenna. The first propagation time or the first phase delay of the received electromagnetic wave and the second propagation time or the second phase delay of the electromagnetic wave incident on the reference fluid from the transmitting antenna and received by the receiving antenna In the electromagnetic wave physical quantity measuring apparatus for calculating the physical quantity of the measurement object present in the substance to be measured by calculating the difference in propagation time or phase delay in comparison with
At least one of the transmitting antenna and the receiving antenna is
A spiral radiating conductor wound in a spiral shape, where the wavelength of the electromagnetic wave is λ, and the length of the spiral axis is λ / 4 or less and the diameter of the spiral is λ / π;
2. An electromagnetic wave physical quantity measuring apparatus comprising: a helical antenna having a ground conductor disposed perpendicular to a spiral axis of the radiation conductor.   The electromagnetic wave physical quantity measuring device according to any one of claims 1 to 6, wherein the surface shape of the ground conductor includes a projected shape of the radiation conductor with respect to the ground conductor.

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