JP4795225B2 - Dielectric waveguide slot antenna - Google Patents

Description

  The present invention relates to a dielectric waveguide antenna which is a waveguide miniaturized with a dielectric material used in a microwave band and a millimeter wave band, and particularly relates to an antenna structure having a notch.

The inventor has proposed a dielectric waveguide slot antenna in a patent application relating to the following published patent. FIG. 4 is a perspective view showing an example. The dielectric waveguide 40 is fixed to the upper surface of the printed circuit board 44 by soldering or the like, and the conductor plate 46 is brought into close contact with the lower surface of the printed circuit board. The bottom surface of the dielectric waveguide 40 is provided with a slot 41 formed by removing a part of the conductor film, and the shape of the via hole 45 of the printed circuit board 44 is substantially equal to the slot 41, Adjustment is made so that the positions of the via holes 45 substantially coincide. A through hole 47 is provided in the conductor plate 46, and this position is also matched with the via hole 45 of the printed circuit board 44. With such a structure, the electromagnetic field radiated from the dielectric waveguide 40 is radiated to free space through the via hole 45 of the printed circuit board 44 and the through hole 47 of the conductor plate 46.

The dielectric waveguide slot antenna has a feature that it can be used as a broadband antenna. FIG. 5 shows an example of the characteristic, which shows that a sufficient gain and a return loss characteristic necessary for an antenna can be obtained in a wide band ranging from 23 GHz to 30 GHz. In recent years, attention has been paid to a communication method such as an ultra-wide band, but in order to avoid interference with an existing wireless communication system, an antenna characteristic that does not emit electromagnetic waves only at a specific frequency may be desired. Conventionally, a band elimination (blocking) filter is separately designed and provided and combined with an antenna. However, this increases the number of components.
JP 2004-221714 A JP 2005-341488 A

  The present invention provides a dielectric waveguide slot antenna with a notch characteristic that does not radiate only a specific frequency without increasing the number of components, and obtains an attenuation pole in gain at a specific frequency in a wide frequency band. A dielectric waveguide slot antenna is provided.

  The present invention solves the above problems by adding a resonator having a notch function to a dielectric waveguide. That is, in a dielectric waveguide slot antenna having a slot in which a dielectric is exposed on one surface of the dielectric, a discontinuous portion is provided between the slot and the end surface of the dielectric, and the tip side of the discontinuous portion And is mounted on a printed circuit board having a via hole formed at a position facing the slot, and the printed circuit board is bonded to a conductor plate having a through hole at a position facing the via hole. It is what has.

  In other words, in a dielectric waveguide slot antenna having a slot in which a dielectric is exposed on one surface of the dielectric, a resonator having a notch function is configured between the slot and the end face of the dielectric, The printed circuit board is mounted on a printed board in which a via hole is formed at a position facing the slot, and the printed board is bonded to a conductor plate having a through hole at a position facing the via hole.

  According to the present invention, the dielectric waveguide slot antenna can have notch characteristics that do not emit only a specific frequency without increasing the number of components. Thereby, unnecessary radiation such as a leakage signal of a local oscillator signal and a harmonic signal from the transmitter can be easily suppressed.

The components of the dielectric waveguide slot antenna according to the present invention are as follows.
Dielectric waveguide: A rectangular parallelepiped dielectric that has a slot on the bottom and a discontinuity such as an iris or a through-hole at the end of the slot. ,
Printed circuit board: A via hole is provided at a position facing the slot.
Conductor plate: A through hole is provided at a position facing the via hole.
The slot, the via hole, and the through hole are aligned.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of the present invention. The dielectric waveguide 10 is fixed to the upper surface of the printed circuit board 14 by soldering or the like, and the conductor plate 16 is brought into close contact with the lower surface of the printed circuit board. The bottom surface of the dielectric waveguide 10, the slot 11 formed by removing part of the conductive film is provided, the shape of the via hole 15 of the printed circuit board 14 and substantially equal to the slot 11, the slot 11 Adjustment is made so that the positions of the via holes 15 substantially coincide. A through hole 17 is provided in the conductor plate 16, and this position is also matched with the via hole 15 of the printed board 14. With such a structure, the electromagnetic field radiated from the dielectric waveguide 10 is radiated to free space through the via hole 15 of the printed board 14 and the through hole 17 of the conductor plate 16. The process up to this point is the same as the conventional one.

  By forming a discontinuous portion called an iris 12 between the end portion of the dielectric waveguide 10 and the slot 11, the end portion of the dielectric waveguide 10 forms a resonator. By appropriately selecting the longitudinal dimension of this terminal short-circuit resonator, the impedance viewed from the input section changes rapidly at the resonance frequency of the resonator. When the length of the resonator is about n / 2 (n is a natural number) of the guide wavelength, the impedance viewed from the input unit becomes zero, the energy is totally reflected, and no electromagnetic wave is emitted at this frequency.

  In FIG. 5, the basic characteristics of an antenna having no resonator at the end of the dielectric waveguide are calculated by an electromagnetic field simulator. On the other hand, FIG. 2 shows an example in which the characteristics of an antenna formed so that the end portion of the dielectric waveguide becomes a resonator is calculated by an electromagnetic field simulator. Both show wide band characteristics operating in the frequency range from 23 GHz to 29 GHz, but in the characteristics shown in FIG. 2, a steep notch characteristic occurs at 26.5 GHz, and it can be seen that no radio waves are emitted at this frequency.

  In this example, the notch characteristic is generated at a frequency substantially at the center of the operating frequency range of the antenna. However, the notch characteristic can naturally be formed at a frequency close to the upper limit or the lower limit of the operating frequency. Further, it is possible to form a notch at a frequency twice or three times the operating frequency. In this case, for example, harmonic signals generated in the local oscillation circuit can be suppressed.

  In order to operate the terminal portion of the dielectric waveguide as a resonator, a groove called an iris is provided in the structure of FIG. 1, but the discontinuous portion for constituting the resonator is not limited to the iris. . As shown in FIG. 3, a structure is also conceivable in which a through hole 13 is provided and this is used as a discontinuous portion to form a resonator.

  The dielectric waveguide slot antenna according to the present invention can be widely used in a wide band and in a high frequency region.

The perspective view which shows the Example of this invention Illustration of its characteristics Perspective view showing another embodiment of book packing A perspective view of a conventional dielectric waveguide slot antenna Illustration of its characteristics

Explanation of symbols

10, 40: Dielectric waveguide
11, 41: Slot
12: Iris
13: Through hole
14, 44: Printed circuit board
15, 45: Beer hall
16, 46: Conductor plate
17, 47: Through hole

Claims (4)

In a dielectric waveguide slot antenna comprising a slot through which a dielectric is exposed on one surface of the dielectric,
A resonator is formed from the discontinuous portion to the tip side including a discontinuous portion between the slot and the end surface of the dielectric,
The dielectric is mounted on a printed circuit board in which a via hole is formed at a position facing the slot,
A dielectric waveguide slot antenna, wherein the printed circuit board is joined to a conductor plate having a through hole at a position facing the via hole. In a dielectric waveguide slot antenna comprising a slot through which a dielectric is exposed on one surface of the dielectric,
A resonator having a notch function is configured between the slot and the end face of the dielectric,
The dielectric is mounted on a printed circuit board in which a via hole is formed at a position facing the slot,
A dielectric waveguide slot antenna, wherein the printed circuit board is joined to a conductor plate having a through hole at a position facing the via hole. 2. The dielectric waveguide slot antenna according to claim 1, wherein the discontinuous portion is an iris. 2. The dielectric waveguide slot antenna according to claim 1, wherein the discontinuous portion is a through hole having a conductor film formed on a wall surface.

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