JP3464108B2 - Feeding structure of laminated dielectric waveguide - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a method of transmitting power to a laminated dielectric waveguide for transmitting high-frequency signals such as microwaves and millimeter waves. The present invention relates to a power supply structure for supplying power. 2. Description of the Related Art Conventionally, waveguides, dielectric waveguides, strip lines, microstrip lines, and the like have been known as lines for transmitting microwave or millimeter wave high-frequency signals. . In a stripline and a microstrip line, since a high-frequency signal propagates on a conductor line, it can be handled in the same manner as a signal line used in a low-frequency region, so that the power supply method is relatively easy. However, in a waveguide or a dielectric waveguide, a high-frequency signal does not propagate on a conductor line, but propagates as an electromagnetic wave in a space surrounded by a conductor. A structure has been proposed. For example, in the case of a dielectric waveguide line in which a dielectric is filled and a metal wall is formed around the dielectric, a hole corresponding to a probe is made in the waveguide, and a metal film is attached to the hole. Method and Figure 4
As shown in FIG. 5, a method of inserting a probe (metal rod) 12 into the waveguide 13 from the end of the microstrip line 11, and as shown in FIG.
There is a method of providing the excitation strip 16 there. On the other hand, a laminated dielectric waveguide has been proposed for forming a dielectric waveguide in a multilayer wiring board in a package for housing a semiconductor element. In this waveguide, a pair of conductor layers are formed on the upper and lower surfaces of a dielectric substrate having a predetermined thickness. The via-hole conductor group for sidewalls is arranged in two rows at the following intervals. [0005] However, although the above-mentioned laminated dielectric waveguide is electromagnetically similar to the dielectric waveguide, the side face of the waveguide is a metal wall. However, since it is made up of through-hole conductors formed at regular intervals and has a special structure formed inside a multilayer wiring board, its manufacturing method is also different from that of a conventional dielectric waveguide. The simplest feed structure for such a laminated dielectric waveguide is a method of inserting a via-hole conductor into a waveguide from a conductor layer and using it as a probe, and forming a via-hole conductor in a feed line and a conductor layer. There is a method of making the slots facing each other to supply power in an electromagnetically coupled manner. However, at present, the excellent transmission characteristics of the laminated dielectric waveguide cannot be sufficiently obtained due to reflection loss due to impedance mismatch, leakage of electromagnetic waves at the feeding section, and the like. Accordingly, an object of the present invention is to provide a dielectric waveguide which can be easily manufactured by using a conventional lamination technique with respect to a laminated dielectric waveguide which can be used as a transmission line in a multilayer wiring board or a semiconductor package. An object of the present invention is to provide a power supply structure for a waveguide. The inventors of the present invention have studied the above problems, and as a result, have found that a via-hole conductor is used to supply power to one of the conductor layers with respect to the laminated dielectric waveguide. By inserting the via-hole conductor into the waveguide and gradually increasing the diameter of the inserted via-hole conductor, it can be easily manufactured by the conventional lamination technology, thereby reducing the impedance mismatch and reducing the reflection. Loss was found to be improved. That is, the feed structure of the laminated dielectric waveguide of the present invention is formed on a dielectric substrate formed by laminating a plurality of ceramic dielectric layers, and at least on the upper and lower surfaces of the dielectric substrate in the line direction. Electrically connecting the first conductor layer and the second conductor layer with the first conductor layer and the second conductor layer in the dielectric substrate, and １ ／ or less of a cutoff wavelength in a line direction. Side wall via-hole conductors arranged in two rows with an interval of, and electrically connected to the side wall via-hole conductors.
And formed in parallel with the main conductor layer, and
For a laminated dielectric waveguide consisting of a sub-conductor layer forming a lattice-like side wall together with a hole conductor group ,
The feeding via hole conductor from the first conductor layer side which is formed vertically against, is inserted into the waveguide without making contact electrically with the conductive layer of the first, the dielectric
The diameter of the power supply via-hole conductor formed in a layer is gradually or continuously increased from the first conductor layer side to the second conductor layer side. FIG. 1 is a schematic perspective view for explaining a feed structure of a laminated dielectric waveguide according to the present invention. In FIG. 1, 1 is a dielectric substrate, 2 and 3 are main conductor layers,
4 is a side wall via-hole conductor, 5 is a sub-conductor layer, 6 is a power supply via-hole conductor, and 7 is a hole formed in the main conductor layer 2. According to the structure shown in FIG. 1, the dielectric substrate 1 has a dielectric layer (1a, 1b, 1c, 1) having a predetermined thickness (x / 4).
d) is formed by laminating four layers. A pair of main conductor layers 2 and 3 are formed on the upper and lower surfaces of the dielectric substrate 1. The main conductor layers 2 and 3 are formed on the upper and lower surfaces of the dielectric waveguide in the line direction. Further, in the dielectric substrate 1, two rows of via-hole conductors 4 for side walls for electrically connecting the main conductor layer 2 and the main conductor layer 3 are formed at intervals y. A plurality of via-hole conductors 4 for sidewalls in each row are formed in the line direction with an interval z of １ ／ or less of the cutoff wavelength. With such a structure, a dielectric waveguide A having a cross section of x × y is formed. On the side wall of the dielectric waveguide A, a sub-conductor layer 5 is formed which is electrically connected to the side wall via-hole conductors 4 and is parallel to the main conductor layers 2 and 3. By the formation of the sub-conductor layer 5, the side wall of the dielectric waveguide has a lattice shape, and leakage of the electromagnetic wave can be more reliably prevented. The predetermined interval y is preferably set to be slightly larger than the half wavelength of the high frequency signal to be transmitted. There is no particular limitation on the predetermined interval x, but when used in the single mode, it is preferable that the predetermined interval x is about の of the interval y, and the predetermined interval z is equal to or less than の of the cutoff wavelength. An electrical wall is formed by setting the interval. In such a configuration, the main mode propagating through the laminated dielectric waveguide is TE10 in which the main conductor layer has an H plane (a plane parallel to the magnetic field). According to FIG. 1, a hole 7 in which no conductor layer is provided is formed in the center of the main conductor layer 2, in which a power supply via-hole conductor 6 is provided with a waveguide. A
Is inserted inside. As described above, by inserting the power supply via-hole conductor 6 vertically into the waveguide A through the hole 7 in the main conductor layer 2, the magnetic field generated by the power supply via-hole conductor 6 is also reduced by the main conductor layers 2 and 3. Because of the parallel configuration, good power supply can be performed. The standard impedance of a line generally used in an electronic circuit is 50Ω. On the other hand, the impedance of a waveguide is generally large, and is 377Ω in a vacuum case. In the laminated dielectric waveguide, since the dielectric is filled inside, the impedance is reduced to 377 / ε1 / ^{2 when} the relative dielectric constant of the dielectric is ε. Even if a dielectric material is used, its impedance becomes 119Ω. Therefore,
If the power supply via-hole conductor 6 has a straight structure (having a constant diameter), the impedance mismatch causes reflection of a high-frequency signal. This means that when viewed from the side of electromagnetic waves, what has been restrained by the outer conductor until now,
This is because the space between the waveguide and the external conductor rapidly expands when it enters the waveguide. Therefore, according to the present invention, as shown in FIG. 1, the diameter of the power supply via-hole conductor 6 is increased stepwise from the main conductor layer 2 to the main conductor layer 3, whereby a sharp impedance is obtained. Changes can be mitigated. FIG. 2 is a view for explaining a method of manufacturing the power supply structure having the structure shown in FIG. This manufacturing method describes a case where ceramic is used as the dielectric substrate 1, and can be easily manufactured by a method similar to the ceramic multilayering technique. Referring to FIG. 2, first, a ceramic powder capable of forming the dielectric substrate 1 is formed into a sheet-like molded product (green sheet) by a doctor blade method or a rolling method. Then, a metallized ink is printed and applied to the green sheet according to each layer, or holes are formed to fill the green sheet with the metallized ink. Specifically, the first green sheet 1
A through hole 6a for power supply is formed in a, and metallized ink is embedded. Further, a through hole 4a for the side wall is formed in the same manner. Thereafter, the main conductor layer 2 is printed on the upper surface of the green sheet 1a so that the upper end of the through hole 6a is inserted into the hole 7. In the second layer green sheet 1b, a power supply through hole 6b and a side wall through hole 4b each having a diameter slightly larger than the diameter of the through hole 6a are formed, metallized ink is embedded therein, and a side wall through hole is further formed. The sub-conductor layer 5b is printed so as to be electrically connected to the hole 4b. Similarly, in the third layer green sheet 1c, a power supply through hole 6c and a side wall through hole 4c slightly larger than the diameter of the through hole 6b are formed, metallized ink is buried therein, and further a side wall through hole 6c is formed. The sub-conductor layer 5c is printed so as to be electrically connected to the through hole 4c. In the fourth layer green sheet, a through hole 4d for a side wall is formed, metallized ink is buried, and a sub-conductor layer 5d is formed on the upper surface so as to be electrically connected to the through hole 4d for the side wall. Print. The main conductor layer 3 is printed on the lower surface. The green sheet 1a thus produced
After sequentially laminating 1 to 1d, they are simultaneously fired to form a feed structure for the laminated dielectric waveguide of the present invention. In the above structure, the diameter of the power supply via hole is set to be gradually increased.
For example, in the above-mentioned manufacturing method, the hole shape of the power supply through holes 6a to 6c is formed in a substantially conical shape having a gradually increasing diameter, filled with metallized ink, and the positions thereof are aligned. It is also possible to form a structure in which the diameter of the conductor 6 increases continuously. When the power supply structure of the laminated dielectric waveguide of the present invention is manufactured by the above-described co-firing technique, for example, when the dielectric ceramic is alumina, the main conductor layer, the sub-conductor layer, the via-hole conductor Is formed of a high melting point metal such as W or Mo. When the dielectric ceramic is glass-ceramic or the like, the main conductor layer, the sub-conductor layer, the side wall, and the via hole for power supply are formed of Cu, Ag, or the like. It is desirable to form. When power is supplied to the laminated dielectric waveguide line from the line end, as shown in FIG. 3, the end surface of the dielectric waveguide line A is a complete conductor wall (castellation). 8 is desirable. Such a conductor wall 8 is difficult with the lamination technique, but if it is configured to coincide with the end face of the multilayer wiring board on which the dielectric waveguide A is formed, the end face of the multilayer wiring board may be plated. The conductor wall 8 can be formed by the method. However, this impairs the degree of freedom of the line forming position. Therefore, if the structure shown in FIG. 3 is adopted, it can be formed anywhere on a plane. FIG. 3 is a view of the present structure as viewed from above the track. An elongated slot 8 is formed at a position of λg / 4 (λg is a guide wavelength in the dielectric waveguide) from the power supply via-hole conductor 6, and a metallized layer is formed on the inner wall surface. With this structure, the electromagnetic wave radiated from the power supply via-hole conductor 6 toward the end of the waveguide A is completely reflected by the conductor wall 8. And
The electromagnetic wave reflected by the conductor wall 8 reinforces in phase with the electromagnetic wave radiated from the power supply via-hole conductor 6 to the endless side,
It will be propagated endlessly. As described in detail above, since the power supply structure of the laminated dielectric waveguide of the present invention is a simple structure, it can be easily applied by using the conventional ceramic lamination technology or the like. It can be manufactured and can provide an excellent power supply structure for a laminated dielectric waveguide.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic perspective view of an embodiment of a feed structure of a laminated dielectric waveguide according to the present invention. FIG. 2 is a view for explaining a method of manufacturing the power supply structure of the laminated dielectric waveguide of FIG. 1; FIG. 3 is a plan view for explaining a structure of an embodiment in a case where power is supplied from an end of the waveguide in a power supply structure of a laminated dielectric waveguide according to the present invention. FIG. 4 is a schematic diagram illustrating an example of a power supply structure in a conventional dielectric waveguide. FIG. 5 is a schematic diagram for explaining another example of a feed structure in a conventional dielectric waveguide. [Description of Signs] 1 Dielectric substrates 2 and 3 Main conductor layer 4 Side wall via-hole conductor 5 Side wall sub-conductor layer 6 Power supply via-hole conductor 7 Hole 8 Conductor wall A Dielectric waveguide

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-77402 (JP, A) JP-A-6-53711 (JP, A) JP-A-10-135714 (JP, A) JP-A-3-13571 34601 (JP, A) Japanese Utility Model Showa 62-58907 (JP, U) Japanese Utility Model Showa 62-114503 (JP, U) Japanese Patent Publication No. 35-13066 (JP, B1) (58) Fields surveyed (Int. ⁷ , DB name) H01P 5/103 H01P 3/12 H01P 5/02 605

Claims (1)

(57) Claims: 1. A dielectric substrate formed by laminating a plurality of ceramic dielectric layers, and first and second dielectric layers formed on at least upper and lower surfaces in a line direction of the dielectric substrate. A first conductor layer and a second conductor layer;
Sidewall via-hole conductors electrically connected between the first conductor layer and the second conductor layer in the dielectric substrate, and arranged in two lines in the line direction at an interval of 以下 or less of a cutoff wavelength Electrically connected to the via hole conductor group for the side wall
And formed in parallel with the main conductor layer,
Sub-conductors that form lattice-like side walls with hole conductors
For a laminated dielectric waveguide comprising
It is inserted a feeding via hole conductor from the first conductor layer side which is formed perpendicularly to the waveguide without electrically with the first conductive layer to contact with each dielectric
Wherein the diameter of the power supply via-hole conductor formed in the body layer is increased stepwise or continuously from the first conductor layer side to the second conductor layer side. Power supply structure of wave tube.