JP2007266868A - Waveguide converter and wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an effective waveguide converter having no radiation from a high-frequency line to an ambient space, and a wiring board with the same. <P>SOLUTION: The waveguide converter includes a high-frequency line consisting of a dielectric substrate having first and second surfaces and consisting of a plurality of layers, and a signal conductor and a ground layer formed in an internal layer of the dielectric substrate; a slot formed on the layer of the dielectric substrate where the ground layer is provided, and electromagnetically coupled to the high-frequency line; a shielding conductor formed in the dielectric substrate, and surrounding a region between the ground layer of the dielectric substrate where the slot is formed and the second surface of the dielectric substrate; and a reflection conductor layer formed on a region corresponding to the slot on the first surface of the dielectric substrate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention converts a high-frequency line such as a microstrip line, a triplate line, or a coplanar line that forms a high-frequency circuit, which is used in a microwave or millimeter wave region, into a waveguide. The present invention relates to a waveguide converter that can easily implement a system by connecting them with a waveguide.

  With the advancement of information communication technology, it has been studied to use high-frequency signals from 1 to 30 GHz in the microwave region to 30 to 300 GHz in the millimeter wave region. Application systems using high-frequency signals have also been proposed.

In such a high frequency system, a slot is formed in the ground layer of the high frequency line, and a waveguide is electrically connected to the ground layer so that the ground layer of the high frequency line functions as a short-circuit termination of the waveguide. The slot formed in the ground layer is used to excite the waveguide, thereby fixing the positional relationship between the short-circuited end of the waveguide and the excitation section, and the dielectric between the excitation slot and the waveguide. A waveguide converter has been proposed in which a conversion characteristic is stabilized by interposing a body matching unit.
JP 2001-177712 A JP 11-112209 A

  However, in this type of waveguide converter, the signal conductor of the high-frequency line is on the same plane as the ground layer where the slot is formed or on the opposite side of the dielectric matching device across the ground layer. When transmitting to a dielectric matching device, a part of the high-frequency signal transmitted through the high-frequency line is radiated in the opposite direction to the dielectric matching device, and the conversion efficiency to the waveguide may be reduced. there were.

  The present invention has been devised in view of the above problems, and an object thereof is to provide a highly efficient waveguide converter and a wiring board including the same without radiation from the high frequency line to the external space. It is in.

The waveguide converter of the present invention has a first and second surfaces, a dielectric substrate composed of a plurality of layers,
Formed in the inner layer of this dielectric substrate, formed in a layer provided with a signal conductor and a ground layer, and a layer provided with the ground layer of the dielectric substrate, and electromagnetically coupled to the high frequency line A slot, a shield conductor formed in the dielectric substrate, surrounding a region between the ground layer in which the slot of the dielectric substrate is formed, and the second surface of the dielectric substrate; And a reflective conductor layer formed in a region corresponding to the slot on one surface.

  In the waveguide converter according to the present invention, preferably, the distance between the ground layer and the reflective conductor layer is ¼ of the signal wavelength.

  The wiring board of the present invention includes the waveguide converter, and is characterized in that an electronic component housing portion is provided in the dielectric layer on which the first surface of the dielectric substrate is formed. .

  The waveguide converter of the present invention has first and second surfaces, and is formed on a dielectric substrate composed of a plurality of layers, and an inner layer of the dielectric substrate, and includes a signal conductor and a ground layer. Formed in a layer provided with a ground layer of a dielectric substrate, a slot electromagnetically coupled to the high frequency line, and a slot formed in the dielectric substrate. A shield conductor that surrounds a region between the ground layer formed with the second surface of the dielectric substrate, and a reflective conductor layer formed in a region corresponding to the slot in the first surface of the dielectric substrate. Therefore, when transmitting a high-frequency signal from a high-frequency line to a dielectric matching device via a slot, a high-efficiency waveguide converter is provided without radiating a high-frequency signal from the high-frequency line to the external space. be able to.

  In the waveguide converter of the present invention, preferably, the distance between the ground layer and the reflective conductor layer is ¼ of the signal wavelength. Therefore, when the high-frequency line and the slot are electromagnetically coupled, the slot to the reflective conductor The high-frequency signal leaked to the layer side is reflected by the reflective conductor layer and returns to the slot again, and most of the high-frequency signal is electromagnetically coupled to the slot, thereby providing a highly efficient waveguide converter.

  The wiring board according to the present invention includes the waveguide converter, and the electronic component housing portion is provided in the dielectric layer on which the first surface of the dielectric substrate is formed. Since it can be mounted adjacent to an efficient waveguide converter, it is possible to provide a wiring board that can be connected to an antenna or other high-frequency circuit and a waveguide with low loss.

  The waveguide converter of the present invention will be described in detail with reference to the drawings. 1A and 1B are schematic views for explaining an example of a waveguide converter according to the present invention. FIG. 1A is a top view and FIG. 1B is a cross-sectional view taken along line A-AA.

  In FIG. 1, 1 is a dielectric substrate, 2 is a signal conductor, 3 is a ground layer, 4 is a high frequency line, 5 is a slot, 6 is a shield conductor, 7 is a dielectric matching unit, 8 is a reflective conductor layer, 9 is The connecting conductor, 10 is a waveguide, and T is the thickness of the reflective layer.

  In the example of the waveguide converter of the present invention, a high frequency line 4 is constituted by a dielectric substrate 1, a signal conductor 2 formed in an inner layer of the dielectric substrate 1, and a ground layer 3. The ground layer 3 is formed with a slot 5 that is electromagnetically coupled to the high-frequency line 4. A shield conductor 6 is formed in a layer between the slot 5 and the second surface of the dielectric substrate 1 so as to surround a region between the slot 5 and the second surface of the dielectric substrate 1, and the dielectric matching device 7 is formed. A reflective conductor layer 8 is formed on the first surface of the dielectric substrate 1, and the reflective conductor layer 8 is separated from the ground layer 3 by a reflective layer thickness T and is electrically connected to each other by a connection conductor 9. Yes. By electrically connecting the open end of the waveguide 10 to the shield conductor 6 on the second surface of the dielectric substrate 1, the high-frequency line 4 is converted into the waveguide 10.

  In this case, the tip of the high-frequency line 4 is opened, and the high-frequency line 4 and the slot 5 are electromagnetically coupled by opening the tip. The ground layer 3 functions as a short-circuit termination of the waveguide 10, and the slot 5 excites the waveguide 10 from the short-circuit termination surface of the waveguide 10. The dielectric matching unit 7 functions as a matching unit for matching the slot 5 serving as the excitation source of the waveguide 10 and the waveguide 10. When a high-frequency signal is transmitted from the high-frequency line 4 to the dielectric matching unit 7 via the slot 5, a part of the high-frequency signal leaks to the reflective conductor layer 8 side, but the region where the reflective conductor layer 8 corresponds to the slot 5. Since the signal leaked to the reflection conductor layer 8 side is covered, it is reflected by the reflection conductor layer 8 and returns to the slot 5 again, and most of the signal is electromagnetically coupled to the slot 5. There is no radiation to the outside space. That is, since all the high frequency signals transmitted through the high frequency line 4 can be transmitted to the dielectric matching device 7 through the slot 5, a highly efficient waveguide converter can be provided. At this time, when the reflection layer thickness T of the reflection conductor layer 8 and the ground layer 3 is set to ¼ times the signal wavelength, the signal leaked from the slot 5 to the reflection conductor layer 8 side is reflected by the reflection conductor layer 8. Return to slot 5 again. The optical path length of the leaked signal at this time is ½ times the signal wavelength by reciprocation, and the phase is inverted. Further, since the reflection on the reflection conductor layer 8 is reflection by the conductor, the phase is reversed. The phase of the leaked signal returns to the original phase when the optical path length and the phase change due to reflection are summed, and becomes the same phase as the signal directly coupled from the high-frequency line 4 to the slot 5 and strengthens each other to form a dielectric. By transmitting to the matching unit 7, a highly efficient waveguide converter can be provided.

  The structure of the reflection layer of this waveguide converter is similar to the structure of the conventional waveguide converter described above, but is completely different in terms of its operating principle. The waveguide excitation source of the conventional waveguide converter is a signal conductor. Therefore, in order to improve the waveguide conversion characteristics, it is necessary to adjust the distance between the signal conductor and the short-circuit termination surface to 1/4 times the signal wavelength. In the reflection layer of the waveguide converter of the present invention, the leakage of the high frequency signal from the high frequency line 4 is generated from the slot 5 which is a discontinuous point of the high frequency line 4. Therefore, in the waveguide converter of the present invention, the thickness T of the reflective layer, which is the distance between the ground layer 3 in which the slot 5 is formed, and the reflective conductor layer 8 is preferably ¼ times the signal wavelength.

  2A and 2B are schematic views for explaining an example of the waveguide converter of the present invention. FIG. 2A is a top view, and FIG. 2B is a B-BB sectional view.

  In FIG. 2, the same parts as those in FIG. An example of the waveguide converter of the present invention is a case where the high-frequency line 4 is a coplanar line. In this example, a dielectric substrate 1, a signal conductor 2, and a ground layer 3 form a coplanar line as a high-frequency line 4. The coplanar line and the slot 5 are electromagnetically coupled by short-circuiting the tip of the signal conductor 2. In this way, the reflective conductor layer 8 is formed on the side opposite to the dielectric matching unit 7 when viewed from the high frequency line 4, so that the high frequency signal leaked from the high frequency line 4 to the reflective conductor layer 8 side is reflected by the reflective conductor layer 8. It is possible to provide a highly efficient waveguide converter that can be reflected and finally transmitted to the dielectric matching unit 7.

  3A and 3B are schematic views for explaining an example of the wiring board according to the present invention. FIG. 3A is a top view and FIG. 3B is a cross-sectional view taken along the line C-CC.

  In FIG. 3, the same parts as those in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and a part forming the first surface of the dielectric substrate 1 is partially deleted to form the accommodating portion 11. . An electronic component 12 is mounted in the storage portion 11, and the electronic component 12 is electrically connected to the signal conductor 2 of the waveguide converter by wire bonding 13. With such a configuration, a high-frequency circuit using the electronic component 12 can be mounted adjacent to the highly efficient waveguide converter, so that wiring that can be connected to the antenna and other high-frequency circuits and the waveguide 10 with low loss. A substrate can be provided.

  It should be noted that the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic for demonstrating an example of the waveguide converter of this invention, (a) is a top view, (b) is AAAA sectional drawing. It is the schematic for demonstrating an example of the waveguide converter of this invention, (a) is a top view, (b) is B-BB sectional drawing. It is the schematic for demonstrating an example of the wiring board of this invention, (a) is a top view, (b) is C-CC sectional drawing.

Explanation of symbols

1: Dielectric substrate 2: Signal conductor 3: Ground layer
4: High-frequency line 5: Slot 6: Shield conductor 7: Dielectric matching unit 8: Reflective conductor layer
9: Connection conductor
10: Waveguide

Claims (3)

A dielectric substrate having first and second surfaces and comprising a plurality of layers;
A high-frequency line formed on the inner layer of the dielectric substrate, comprising a signal conductor and a ground layer;
Formed in a layer provided with the ground layer of the dielectric substrate, and a slot electromagnetically coupled to the high-frequency line;
A shield conductor formed in the dielectric substrate and surrounding a region between the ground layer in which the slot of the dielectric substrate is formed and the second surface of the dielectric substrate;
A waveguide converter, comprising: a reflective conductor layer formed in a region corresponding to the slot on the first surface of the dielectric substrate. The waveguide converter according to claim 1, wherein a distance between the ground layer and the reflective conductor layer is ¼ of a signal wavelength. A waveguide converter according to claim 1 or 2, wherein an electronic component storage portion is provided on a dielectric layer on which the first surface of the dielectric substrate is formed. Wiring board to be used.

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