JPH05183306A - Dielectric board for tri-plate structure - Google Patents

Abstract

PURPOSE:To obtain an accurate block frequency by providing a dielectric base having a conductor line and a ground plane and a dielectric base having a conductor line in face symmetry to the conductor line and having a ground plane and bonding the conductor line symmetrically. CONSTITUTION:A dielectric base 10 has a conductor line 11 formed by silk print or the like, a stub 12 and an earth plane 14. Furthermore, a dielectric base 20 also has a conductor line 21, a stub 22 and a ground plane 24 similarly to the case with the dielectric base. Planes 13, 23 of the dielectric bases 10, 20 are opposite to each other, and the conductor line 11 and the stub 12 and the conductor line 21 and the sub 22 are arranged to a position in face symmetry. Then the conductor lines 11, 21 are bonded symmetrically to form the tri-plate structure with the dielectric bases 10, 20. Thus, no air layer no adhesives is in existence between the conductor lines 11, 21 and the dielectric bases 10, 20, and the electric characteristic of the block frequency as the design value is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric substrate, and more particularly to a triplate structure dielectric substrate.

[0002]

2. Description of the Related Art A conventional dielectric substrate is used for a filter for high frequency transmission. As shown in FIG. 4, a conductor line (strip line) 2 and a stub 3 are provided on the upper side and a ground plane 4 is provided on the lower side. Is composed of a dielectric substrate 1 formed by known silver silk printing or the like, and a dielectric substrate 5 on which an earth plane 6 is formed by the silver silk printing or the like, and both substrates 1 and 5 are simply pressed. Alternatively, the filter has been manufactured by bonding with an adhesive. It should be noted that both substrates 1 and 5 are
Were made from ceramics, fused silica, etc.

[0003]

However, in the above dielectric substrate, for example, when both the substrates 1 and 5 are simply pressed, an air layer is adhered to the contact portion between the substrate and the stub, and an adhesive agent is used. However, there is a problem in that an adhesive layer is present at the contact portion between the substrate and the stub, which causes the set frequency to be displaced and an accurate stop frequency cannot be obtained.

This is equivalently shown in an experiment of a stripline filter. In this experimental example, a strip line filter is manufactured by bringing a conductor line formed on a dielectric substrate into contact with a stub made of aluminum foil and providing a ground surface under the substrate. In this example, the dielectric substrate 1
A filter having a permittivity of 74 and a stop frequency of f ₀ [Hz] is designed.

In the above experimental example, an air layer is present at the contact portion between the substrate and the stub, so that the blocking frequency is set to 1.38f ₀ [HZ] from the set frequency f ₀ [HZ] as shown in FIG. 5, for example.
Z]], and an accurate stop frequency could not be obtained. Therefore, the apparent dielectric constant of the dielectric substrate is, as shown in Table 1,

[0006]

[Table 1] There is a problem in that the displacement is large compared to the actual permittivity of the dielectric substrate.

The present invention has been made in view of the above problems, and an object thereof is to provide a dielectric substrate having a triplate structure capable of obtaining an accurate stop frequency.

[0008]

In order to solve the above-mentioned object, the present invention provides a dielectric substrate having a conductor line and a ground plane, and a dielectric substrate having a plane-symmetrical conductor line and a ground plane. A dielectric substrate having a triplate structure, in which the conductor lines are symmetrically joined to each other, is provided.

[0009]

The conductor lines of the two dielectric substrates which are plane-symmetrical are joined electrically and physically by, for example, soldering or a conductive adhesive. Therefore, a substance having another permittivity does not exist at the contact portion between the conductor line and the dielectric, and the electrical characteristic of the blocking frequency is obtained only by the permittivity of the actual dielectric substrate.

[0010]

Embodiments of the present invention will be described with reference to the drawings of FIGS. FIG. 1 is an assembly diagram showing assembly of a dielectric substrate according to the present invention. In the figure, the dielectric substrate 10 is
It has a conductor line 11 and a stub 12 formed by known silk printing and the like, and a ground plane 13. The conductor line 11 and the stub 12 are formed on the same surface 13, and the ground surface 14 is formed on a surface facing the surface 13 on which the conductor line 11 and the stub 12 are formed.

The dielectric substrate 20 is also the dielectric substrate 10.
Similar to the above, the conductor line 21 formed by silk printing or the like
And a stub 22 and a ground plane 23. The conductor line 21 and the stub 22 are formed on the same surface 23,
The ground surface 24 is formed on a surface facing the surface 23 on which the conductor line 21 and the stub 22 are formed. The surfaces 13 and 23 of the dielectric substrates 10 and 20 are opposed to each other, and the conductor line 11 and the stub 12 and the conductor line 21 and the stub 22 are arranged at positions symmetrical to each other.

In the dielectric substrate of the present invention, as shown in FIG. 2, the conductor lines 11 and 21 are symmetrically joined to form a triplate structure in which the dielectric substrates 10 and 20 are combined. As a method of joining the conductor lines 11 and 21, for example, a method of applying cream solder to the conductor lines 11 and 21, pasting the dielectric substrates 10 and 20 together, and further heating and joining them, or a SUPER SOLDER PRECOAT. (Our technology)

Therefore, in this embodiment, since the dielectric substrate having the triplate structure is formed, the air layer and the adhesive are not present between the conductor line and the dielectric, and the dielectric substrate is used as in the conventional example. The body substrate 1 has a dielectric constant of 74 and a stop frequency of f
_When designing a filter of ₀ [Hz], as shown in FIG. 3, the stop frequency does not deviate from the set frequency f ₀ [Hz] due to only the permittivity of the actual dielectric substrate, and the design value It is possible to obtain the electrical characteristics of the stop frequency as it is.

[0014]

As described above, the present invention comprises a dielectric substrate having a conductor line and a ground plane, and a dielectric substrate having a plane-symmetrical conductor line and a ground plane. Since the conductor lines are symmetrically joined to each other, an accurate stop frequency as designed can be obtained.

[Brief description of drawings]

FIG. 1 is an assembly diagram showing an assembled state of a dielectric substrate according to the present invention.

FIG. 2 is a plan view in the case where the dielectric substrates shown in FIG. 1 are combined to form a triplate structure.

FIG. 3 is a diagram showing frequency electric characteristics when a filter is designed using a dielectric substrate having a triplate structure according to the present invention.

FIG. 4 is an assembly view showing an assembled state of a conventional dielectric substrate having a triplate structure.

FIG. 5 is a diagram showing frequency electric characteristics in an experimental example in which a stripline filter is equivalently designed.

[Explanation of symbols]

 10,20 Dielectric substrate 11,21 Conductor line 12,22 Stub 13,23 Dielectric substrate surface 14,24 Ground plane

Claims (1)

[Claims] 1. A dielectric substrate having a conductor line and a ground plane, and a dielectric substrate having a plane symmetry with the conductor line and a dielectric substrate having a ground plane, wherein the respective conductor lines are symmetrically joined to each other. Characteristic Tri-plate structure dielectric substrate.