JP2011024176A - Electromagnetic wave transfer unit for dielectric waveguide - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow not a conventional metal waveguide, but coaxial cable, a microstrip line and a strip line to be connected to a dielectric waveguide. <P>SOLUTION: An electromagnetic wave transfer unit is connected to a dielectric waveguide via a printed circuit board antenna, in particular, via a tapered slot antenna and a Fermi antenna. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to transmission of electromagnetic waves from a transmission line such as a coaxial cable, two-core parallel lines, and a coplanar line to a dielectric waveguide or vice versa.

When transmitting millimeter waves, terahertz waves, and waves in the optical region, transmission modes with less energy distribution in the metal part such as dielectric waveguides (here, image lines and surface wave lines are also included) are becoming important. It was. This can be seen from the fact that the insertion loss of the dielectric waveguide is reduced to about a fraction of that of the metal waveguide. The circuit portion is often composed of a strip line, a microstrip line, a coplanar line, and a coaxial cable. That is, it has become necessary to connect these two transmission lines.
Until now, the coupling between the metal waveguide and the dielectric waveguide has been the main.

  There has been a need to develop means for transmitting electromagnetic waves from striplines, microstriplines, coplanar lines and coaxial cables to dielectric waveguides.

The printed circuit board antenna is thin, and can be easily connected to a strip line, microstrip line, coplanar line, and coaxial cable. On the other hand, it is only necessary to focus electromagnetic radiation from the antenna on a dielectric waveguide. .
The tapered slot line emits radio waves in a direction parallel to the printed circuit board. In addition, if a high gain design is used, 90% or more of the electromagnetic wave enters the dielectric waveguide. Furthermore, if a Fermi antenna is used, it can be used in a wide frequency band of 1 octave or more.
The industrial property numbers of Fermi antennas are as follows.
Japanese Patent No. 3434655 “Plane antenna and antenna array”
Japanese Patent No. 3462959 “Plane Antenna”

Example 1 is shown below. As an example of the printed circuit board antenna, a tapered slot antenna shown in FIG. 1 will be described. The hatched portion is a conductor pattern, and the central conductor of the coaxial cable 3 is connected to the upper conductor. The outer conductor of the coaxial cable is connected to the lower conductor. Since the coaxial cable is an unbalanced cable, the portion of the lower conductor portion that falls vertically plays the role of a balun. As this antenna goes to the right side, it spreads in a trumpet shape, and the radio wave goes in the right direction. The electric field is in the direction of 4. In the case of reception, radio waves coming from the left are received. In addition, transmission lines that can be connected to the antenna include a strip line, a microstrip line, and a coplanar line.

Example 2 is shown below. A Fermi antenna shown in FIG. 2 will be described as an example of a printed circuit board antenna. The difference between this antenna and the first embodiment is that one conductor is on the back side of the printed circuit board and there are corrugated corrugations on both wings of the conductor. Note that the corrugate serves to widen the frequency band. Both tapered slot antennas and Fermi antennas radiate in the right direction. When these antennas are sandwiched between dielectrics, radio waves are focused on the dielectrics and travel.

Example 3 is shown below. FIG. 3 shows an example in which a printed circuit board antenna is disposed at the strongest electric field portion of the dielectric waveguide. When a rectangular groove is dug in the center in the width direction of the dielectric waveguide, and the antenna is buried in this groove, the electromagnetic wave efficiently proceeds to the right. When the electromagnetic wave proceeds from the right, the antenna receives the electromagnetic wave efficiently. The dielectric waveguide 8 is an electromagnetic wave transmission part, and is generally called a core part. If this core is wrapped with a material having a dielectric constant lower than that of the core, even if this part is touched, the insertion loss is not affected. This is called a clad, and although not shown in the figure, a clad may be provided.

Example 4 is shown below. An example in which a printed circuit board antenna is disposed on the wall surface of the dielectric waveguide is shown in FIG. There is an electric field perpendicular to the wall surface, and electromagnetic waves are transmitted. However, since the electric field strength of the waveguide is weak, the electromagnetic wave conversion efficiency is poor. However, it is not necessary to dig a groove in the waveguide, and the electromagnetic wave transmission unit can be moved. Electromagnetic waves can be transmitted while running the electromagnetic wave transmission unit.

Example 5 is shown below. FIG. 5 shows an example in which a printed circuit board antenna is disposed at the end of the dielectric waveguide. This method is generally good for connecting the transmission line and the transmission line.

Example 6 is shown below. This is an example where the electric field direction of the dielectric waveguide is 1 m or more in the case of the fourth embodiment. When the width of the dielectric waveguide in the direction of the electric field is increased, the electromagnetic wave travels in the direction toward the antenna when the direction of the printed circuit board antenna is changed. If a similar antenna is placed on the opposite side and both antennas are opposed, one-to-one communication on the surface becomes possible.

Example 7 is shown below. If a layer having a dielectric constant lower than that of the dielectric waveguide is provided outside the dielectric waveguide, and a printed circuit board antenna is provided in that portion, the transmission efficiency with the dielectric waveguide becomes poor. However, since the electric field strength outside the layer having a low dielectric constant is weak, touching it does not affect the transmission path. It is also free to move the antenna or change the direction of the antenna.

An example of a tapered slot antenna. An example of a Fermi antenna. An example in which a printed circuit board antenna is disposed in the strongest part of the electric field. An example in which a printed circuit board antenna is disposed on the wall surface of a dielectric waveguide. The example which has arrange | positioned the printed circuit board antenna in the edge part of a dielectric waveguide. The example in case the electric field direction of a dielectric waveguide is 1 m or more.

1. 1. Tapered slot antenna 2. Printed circuit board antenna 3. Direction of electric field 4. Direction of travel of electromagnetic field Fermi antenna6. Coaxial cable7. Printed circuit board antenna8. Dielectric waveguide

Claims (8)

An electromagnetic wave transmission unit in which a printed circuit board antenna for transmission or reception is arranged so that the electric field direction perpendicular to the traveling direction of the electromagnetic wave in the dielectric waveguide coincides with the electric field direction of the antenna. 2. An electromagnetic wave transmission section according to claim 1, wherein a printed circuit board antenna is disposed at the strongest portion of the electric field of the dielectric waveguide. 2. The electromagnetic wave transmission unit according to claim 1, wherein a printed circuit board antenna is disposed on a wall surface of the dielectric waveguide. The electromagnetic wave transmission unit according to claim 3, wherein a printed circuit board antenna is disposed at an end of the dielectric waveguide. 2. The electromagnetic wave transmission unit according to claim 1, wherein an electric field direction of the dielectric waveguide is 1 m or more. 6. The electromagnetic wave transmission unit according to claim 4, wherein a layer having a dielectric constant lower than that of the dielectric waveguide is provided outside the dielectric waveguide, and a printed circuit board antenna is disposed on the layer. The electromagnetic wave transmission unit according to claim 1, wherein the printed circuit board antenna is a tapered slot antenna. The electromagnetic wave transmission unit according to claim 1, wherein the printed circuit board antenna is a Fermi antenna.

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