JP2005051330A - Connection structure between dielectric waveguide line and high frequency transmission line, high frequency circuit board employing the same, and high frequency element mount package - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connection structure for electromagnetically coupling a dielectric waveguide line to a signal transmission through-conductor at a low loss and the profile of which is made low. <P>SOLUTION: The connection structure for the dielectric waveguide line 10 and a high frequency transmission line 6 is used to couple the high frequency transmission line 6, located to the dielectric waveguide line 10 via a dielectric layer 9, to the dielectric waveguide line 10 surrounded by a pair of major conductor layers 2, 3, two columns of a side wall use through-conductor group 4, and an end face use through-conductor group 5. The high frequency transmission line 6 includes a signal transmission use through-conductor 7 extended from the end of the high frequency transmission line 6 without being connected to the major conductor layers 2, 3 so that the tip is inserted from the end face use through-conductor group 5 into the dielectric waveguide line 10 by a distance of 1/4 of a guide wavelength, and the signal transmission use through-conductor 7 is formed with a circular projection 8 formed concentrically with the through-conductor 7 for signal transmission at a position located in the dielectric waveguide line 10. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a connection structure for coupling a dielectric waveguide line for transmitting high-frequency signals such as microwaves and millimeter waves and other high-frequency transmission lines, a high-frequency circuit board using the connection structure, and a high-frequency circuit. The present invention relates to an element mounting package.
[0002]
[Prior art]
Conventionally, coaxial lines, waveguides, dielectric waveguides, microstrip lines, and the like are known as lines for transmitting microwave and millimeter wave high-frequency signals. Also, there is known a coupling technique in which a plurality of different types of lines are arranged in a wiring circuit and a signal is transmitted by electromagnetic coupling between these lines. For example, a signal transmission through conductor pin 37 and a metal shown in FIG. In the connection structure with the waveguide 40, signals are transmitted by electromagnetic coupling between the signal transmission through conductor pins 37 inserted into the through holes 40 a formed in the metal waveguide 40 and the metal waveguide 40. A signal is transmitted from the high-frequency transmission line 36 to the metal waveguide 40. In FIG. 12, reference numeral 31 denotes a dielectric substrate.
[0003]
In recent years, dielectric waveguide lines have been formed in a multilayer circuit board by a lamination technique. For example, the dielectric waveguide lines shown in the perspective view of FIG. 10 and the cross-sectional view of FIG. And a high-frequency transmission line connection structure have been proposed. In such a connection structure, the dielectric waveguide 21 is formed by sandwiching the dielectric substrate 21 between the pair of main conductor layers 22 and 23 and further connecting the main conductor layers 22 and 23 with two rows of through conductor groups 24 for side walls. The dielectric waveguide line 30 and the high frequency transmission line 26 can be electrically connected by inserting the signal transmission through conductor 27 from the end of the high frequency transmission line 26 into the line 30. In FIG. 10, reference numeral 25 denotes an end surface through conductor group.
[0004]
[Patent Document 1]
JP-A-10-135714
[0005]
[Problems to be solved by the invention]
However, in the conventional connection structure of the dielectric waveguide line 30 and the line conductor 26, as shown in FIG. 10, when the line conductor 26 is a coplanar line formed on the main conductor layers 22 and 23, the line conductor 26 and the signal transmitted through the dielectric waveguide line 30 cause interference and the transmission characteristics are deteriorated.
[0006]
In addition, with the recent downsizing and thinning of electronic devices, it is necessary to reduce the thickness of the wiring board, and the connection structure between the dielectric waveguide line 30 and the high-frequency transmission line 26 formed on the wiring board is increased. The need to reduce the height has arisen. In response to such a demand, if the dielectric substrate 21 is made thin in order to reduce the height of the connection structure between the dielectric waveguide line 30 and the high-frequency transmission line 26 formed by the conventional lamination technique, signal transmission is performed. There is a problem in that an electric capacity is generated between the lower end portion of the through-hole conductor 27 and the main conductor layer 23, and transmission characteristics at a desired frequency deteriorate.
[0007]
Therefore, the present invention has been completed in view of the above-mentioned conventional problems, and its object is to provide a dielectric waveguide line that can be easily manufactured by a conventional multilayer technology, and a signal transmission through conductor. Are connected to each other with low loss, and the connection structure between the dielectric waveguide line and the high-frequency transmission line is reduced in height.
[0008]
[Means for Solving the Problems]
The connection structure of the dielectric waveguide line and the high-frequency transmission line according to the present invention includes a pair of main conductor layers sandwiching the dielectric substrate from above and below, and a half of the in-tube wavelength of the high-frequency signal in the transmission direction of the high-frequency signal. Two sidewall through-conductor groups that are electrically connected between the pair of main conductor layers formed at a repetitive interval of less than 1, and the sidewall penetration at one end of the two rows of sidewall through-conductor groups A dielectric conductor for transmitting the high-frequency signal by a region surrounded by end surface through conductor groups electrically connecting the pair of main conductor layers formed in a row between the conductor groups in a row. A connection structure of a dielectric waveguide line and a high-frequency transmission line for coupling a high-frequency transmission line disposed in parallel with the transmission direction via a dielectric layer to either the top or bottom of the wave-tube line The high-frequency transmission line includes the end surface through conductor. From the end portion of the high-frequency transmission line, the tip is inserted into the dielectric waveguide line at a distance of one-fourth of the guide wavelength from the end face of the dielectric waveguide line formed with The signal transmission through conductor is extended without being connected to the main conductor layer, and the signal transmission through conductor is inserted into the signal transmission through at a portion located in the dielectric waveguide line. A circular protrusion is formed concentrically with the conductor.
[0009]
The connection structure between the dielectric waveguide line and the high-frequency transmission line according to the present invention is such that the high-frequency transmission line is a quarter of the in-tube wavelength from the end face of the dielectric waveguide line on which the end face through conductor group is formed. Because it has a signal transmission through conductor extended without being connected to the main conductor layer from the end of the high-frequency transmission line so that the tip is inserted into the dielectric waveguide line at a distance, The loss of the high frequency signal due to the electrical cancellation of the high frequency signal excited by the signal transmission through conductor and radiated into the dielectric substrate and the high frequency signal reflected by the end surface through conductor group. It can be effectively reduced. Therefore, it is possible to efficiently radiate a high-frequency signal forward (on the opposite side to the end face through conductor group) and to extract it to the outside with low loss.
[0010]
In addition, since the signal transmission through conductor has a circular protrusion formed concentrically with the signal transmission through conductor at a portion located in the dielectric waveguide line, It is possible to reduce the height of the connection structure while maintaining the low-loss electrical characteristics of the connection structure with the high-frequency transmission line. That is, the frequency f excited between the signal transmission through conductor and the main conductor layer is f = 1 / 2π (LC). ^1/2 (L: Reactance amount of the signal transmission through conductor, C: Capacity generated between the signal transmission through conductor and the main conductor layer). If the insertion length of the signal transmission through conductor is shortened, the L of the signal transmission through conductor decreases, and the excitation frequency tends to shift to a higher frequency side than the frequency to be obtained. C generated between the body layer and the body layer can be increased, and the frequency to be excited can be shifted to the low frequency side. As a result, since the product LC value can be kept constant without changing, the frequency f can be maintained at a value to be obtained, and the dielectric can be shortened while maintaining the electrical characteristics of the signal transmission through conductor. The waveguide line can be reduced in height.
[0011]
Thus, according to the present invention, it is possible to easily connect the dielectric waveguide line, the microstrip line, and the coplanar line. In addition, since it can be easily manufactured by using a conventionally known ceramic multilayering technique, a low-cost and highly reliable low-profile coupling structure can be configured.
[0012]
In the connection structure between the dielectric waveguide line and the high-frequency transmission line of the present invention, preferably, the distance between the projecting portion and the upper main conductor layer is between the lower main conductor layer. It is characterized by being larger than the distance.
[0013]
In the connection structure between the dielectric waveguide line and the high-frequency transmission line according to the present invention, the distance between the protrusion and the upper main conductor layer is larger than the distance between the protrusion and the lower main conductor layer. Since it is large, it is possible to effectively suppress the deterioration of transmission characteristics due to the generation of unnecessary stray capacitance between the protruding portion and the conductor positioned above the dielectric waveguide line. That is, since the entire surface of the lower surface of the dielectric waveguide is covered with the main conductor layer, the protruding portion is electrically cut off from the conductor located below the dielectric waveguide. In the main conductor layer immediately above the protrusion, a hole for introducing the signal transmission through conductor into the dielectric waveguide line is formed. At the hole, the protrusion and the dielectric conductor are formed. Since electrical disconnection from the conductor located above the wave guide line is incomplete and unnecessary stray capacitance is likely to occur between them, the distance between the upper main conductor layer and the protruding portion is increased. By doing so, the generation of this stray capacitance can be suppressed.
[0014]
In the connection structure between the dielectric waveguide line and the high-frequency transmission line according to the present invention, preferably, the protruding portion is located above a lower end of the signal transmission through conductor.
[0015]
In the connection structure between the dielectric waveguide line and the high-frequency transmission line according to the present invention, since the protruding portion is located above the lower end of the signal transmission through conductor, the reflection loss at the lower end of the signal transmission through conductor. Can be effectively suppressed and the transmission characteristics can be made very good. That is, if a protruding portion is provided at the lower end of the signal transmission through conductor, the diameter of the lower end of the signal transmission through conductor increases rapidly, so that the loss of the high-frequency signal reflected at the lower end tends to become very large. By providing the diameter of the signal transmission through conductor without providing the protrusions, the reflection loss can be effectively suppressed.
[0016]
The high-frequency circuit board of the present invention is characterized in that a dielectric substrate is provided with a connection structure between the dielectric waveguide line and the high-frequency transmission line configured as described above and a mounting portion for mounting a high-frequency element. .
[0017]
With the above configuration, the high-frequency circuit board of the present invention has low-loss electrical characteristics and can be easily reduced in thickness.
[0018]
The high frequency device mounting package of the present invention is characterized in that a lid is attached so as to cover the mounting portion of the high frequency circuit board having the above-described configuration.
[0019]
The high-frequency element mounting package of the present invention can provide a thin high-frequency element mounting package having low-loss electrical characteristics by the above configuration.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
The connection structure between the dielectric waveguide line and the high-frequency transmission line of the present invention will be described in detail below. 1 is a perspective view showing an example of an embodiment of the connection structure of the present invention, FIG. 2 is a plan view of the connection structure of FIG. 1, and FIG. 3 is a cross-sectional view of the connection structure of FIG. In these drawings, 1 is a dielectric substrate, 2 and 3 are main conductor layers, 4 is a through conductor group for side walls, 5 is a through conductor group for end faces, 6 is a high-frequency transmission line, 7 is a through conductor for signal transmission, 8 Is a dielectric layer, 9 is a dielectric layer, 10 is a dielectric waveguide, and 11 is a coplanar ground conductor layer.
[0021]
As shown in FIG. 1, a dielectric substrate 1 having a thickness t is provided with a pair of main conductor layers 2 and 3 so as to sandwich it. The main conductor layers 2 and 3 are respectively formed on the upper and lower surfaces so as to sandwich at least a position where the dielectric waveguide line 10 is formed on the dielectric substrate 1. Between the main conductor layers 2 and 3, two rows of through-hole conductor groups 4 for connecting the side walls are provided. The side wall through conductor groups 4 are formed in two rows with a predetermined interval s. Further, these through-hole conductor groups 4 for the side walls are formed in the line direction with a repetition interval of less than one half of the guide wavelength. An electrical wall (conductor wall) is formed by setting at this repetition interval, and as a result, a structure similar to the waveguide, that is, the dielectric waveguide line 10 is formed.
[0022]
According to the present invention, the high-frequency transmission line 6 is formed from the end face through conductor group 5 of the dielectric waveguide line 10 to a quarter position in the signal transmission direction, and the signal transmission through conductor is formed from the end. 7, and the lower end portion of the signal transmission through conductor 7 is inserted into the dielectric waveguide line 10 to electromagnetically couple the high frequency transmission line 6 and the dielectric waveguide line 10.
[0023]
The upper surface of the dielectric waveguide line 10 is the main conductor layer 2. By providing a hole 2 a larger in diameter than the signal transmission through conductor 7 in the main conductor layer 2, the main conductor layer 2 and the signal transmission penetration are provided. The signal transmission through conductor 7 is inserted into the dielectric waveguide line 10 in a state where the conductor 7 is electrically insulated.
[0024]
Further, the signal transmission through conductor 7 includes a circular projecting portion 8 concentrically with the signal transmission through conductor 7 at a portion located in the dielectric waveguide line 10.
[0025]
At this time, the signal transmission through conductor 7 and the protruding portion 8 are formed so as not to be electrically connected to the main conductor layer 3 on the lower surface. This is because the transmission characteristics deteriorate when the signal transmission through conductor 7 and the protrusion 8 are connected to the main conductor layer 3 on the lower surface. For this reason, as shown in FIG. 3, the insertion length of the signal transmission through conductor 7 into the dielectric waveguide line 10 is larger than the thickness t of the dielectric substrate 1 constituting the dielectric waveguide line 10. It is formed to be shorter.
[0026]
Since the large main conductor layer 2 is formed on the upper side with respect to the signal transmission through conductor 7 and the protrusion 8, the signal transmission through conductor 7 and the protrusion 8 have a function of a capacity-loaded monopole antenna. It will be a thing.
[0027]
Further, if the length of the signal transmission through conductor 7 to the dielectric waveguide line 10 is set to about a quarter of the wavelength of the transmitted high-frequency signal, the electromagnetic wave propagating through the high-frequency transmission line 6 is a signal. Radiated into the dielectric waveguide line 10 by the transmission through conductor 7. However, it is necessary to adjust the diameter and length of the signal transmission through conductor 7 and the diameter of the protrusion 8 depending on the wavelength of the high-frequency signal and the position where the protrusion 8 is formed. Therefore, by setting the thickness t of the dielectric waveguide line 10 to about half of the interval s between the two side wall through conductor groups 4, the high frequency signal radiated from the signal transmission through conductor 7 is changed to TE. ₁₀ The mode can be propagated efficiently in the dielectric waveguide line 10 with the mode as the main mode.
[0028]
The connection structure between the dielectric waveguide line 10 and the high-frequency transmission line 6 according to the present invention is such that the high-frequency transmission line 6 has an in-tube wavelength from the end face of the dielectric waveguide line 10 on which the end face through conductor groups 5 are formed. For signal transmission extended from the end of the high-frequency transmission line 10 without being connected to the main conductor layers 2 and 3 so that the tip is inserted into the dielectric waveguide line 10 at a quarter distance Since the through-conductor 7 is provided, the high-frequency signal excited in the signal transmission through-conductor 7 and radiated into the dielectric substrate 1 and the high-frequency signal in which the high-frequency signal is reflected by the end-surface through-conductor group 5 are provided. It is possible to effectively reduce the loss of the high-frequency signal due to the electrical cancellation of each other. Therefore, it is possible to efficiently radiate a high-frequency signal forward (on the side opposite to the end face through conductor group 5) and to extract it to the outside with low loss.
[0029]
In addition, since the signal transmission through conductor 7 has a circular protrusion 8 formed concentrically with the signal transmission through conductor 7 at a portion located in the dielectric waveguide line 10, It is possible to reduce the height of the connection structure while maintaining the low-loss electrical characteristics of the connection structure between the wave tube line 10 and the high-frequency transmission line 6. That is, the frequency f excited between the signal transmission through conductor 7 and the main conductor layers 2 and 3 is f = 1 / 2π (LC). ^1/2 (L: Reactance amount generated in the signal transmission through conductor 7, C: capacitance generated between the signal transmission through conductor 7 and the main conductor layers 2 and 3), the signal transmission through conductor 7 is inserted. When the length is shortened, L decreases between the signal transmission through conductor 7 and the main conductor layers 2 and 3, and the excitation frequency tends to shift to a higher frequency side than the frequency to be obtained. C generated between the through-conductor 7 for use and the main conductor layers 2 and 3 can be increased, and the frequency to be excited can be shifted to the low frequency side. As a result, since the product LC value can be made constant without changing, the frequency f can be maintained at a value to be obtained, and the dielectric property can be shortened while maintaining the electrical characteristics of the signal transmission through conductor 7. The body waveguide line 10 can be reduced in height.
[0030]
The dielectric substrate 1 and the dielectric layer 9 may be made of a material most suitable for forming a dielectric waveguide line 10 and a high-frequency transmission line 6, for example, a microstrip line or a coplanar line. It is not necessarily made of the same material.
[0031]
Moreover, it is preferable that the distance between the protrusion 8 and the upper main conductor layer 2 is larger than the distance between the protrusion 8 and the lower main conductor layer 3. As a result, it is possible to effectively suppress the generation of unnecessary stray capacitance between the protruding portion 8 and the conductor positioned above the dielectric waveguide line 10 to deteriorate the transmission characteristics. That is, since the entire surface of the dielectric waveguide 10 is covered with the main conductor layer 3, the protruding portion 8 is electrically cut off from the conductor located below the dielectric waveguide 10. However, in the main conductor layer 2 immediately above the projecting portion 8, a hole 2a for introducing the signal transmission through conductor 7 into the dielectric waveguide line 10 is formed. This hole 2a In this portion, the electrical disconnection between the protruding portion 8 and the conductor positioned above the dielectric waveguide line 10 is incomplete, and unnecessary stray capacitance is likely to be generated between them, so the upper lead By increasing the distance between the body layer 2 and the protruding portion 8, the generation of this stray capacitance can be suppressed.
[0032]
Furthermore, it is preferable that a plurality of protrusions 8 are formed. As a result, the plurality of protrusions 8 can be capacitively coupled to the upper and lower main conductor layers 2 and 3, and a larger capacitance value C can be obtained. As a result, the insertion length of the signal transmission through conductor 7 into the dielectric waveguide line 10 can be shortened, and the connection structure between the dielectric waveguide line 10 and the high frequency transmission line 6 can be further reduced. Can be turned upside down.
[0033]
When a plurality of the protrusions 8 are formed, the distance between the uppermost protrusion 8 and the upper main conductor layer 2 is such that the lowermost protrusion 8 and the lower main conductor layer 3 It should be larger than the distance between. As a result, it is possible to effectively suppress the generation of unnecessary stray capacitance between the protruding portion 8 and the conductor positioned above the dielectric waveguide line 10 to deteriorate the transmission characteristics. That is, since the entire surface of the dielectric waveguide 10 is covered with the main conductor layer 3, the protruding portion 8 is electrically cut off from the conductor located below the dielectric waveguide 10. However, in the main conductor layer 2 immediately above the projecting portion 8, a hole 2a for introducing the signal transmission through conductor 7 into the dielectric waveguide line 10 is formed. This hole 2a In this portion, the electrical disconnection between the protruding portion 8 and the conductor positioned above the dielectric waveguide line 10 is incomplete, and unnecessary stray capacitance is likely to be generated between them, so the upper lead By increasing the distance between the body layer 2 and the protruding portion 8, the generation of this stray capacitance can be suppressed.
[0034]
The protrusion 8 is preferably positioned above the lower end of the signal transmission through conductor 7. Thereby, the reflection loss at the lower end of the signal transmission through conductor 7 can be effectively suppressed, and the transmission characteristics can be made very good. That is, when the protruding portion 8 is provided at the lower end of the signal transmission through conductor 7, the diameter of the lower end of the signal transmission through conductor 7 increases rapidly, so that the loss of the high frequency signal reflected at the lower end tends to be very large. Therefore, the reflection loss can be effectively suppressed by setting the diameter of the signal transmission through conductor 7 without providing the protruding portion 8 at the lower end.
[0035]
Next, FIGS. 4 to 6 show other preferable examples of the connection structure of the present invention, FIG. 4 is a perspective view of the connection structure, FIG. 5 is a plan view of the connection structure of FIG. 6 is a cross-sectional view of the connection structure of FIG. In these drawings, reference numeral 12 denotes a ground penetrating conductor group, and the others are the same as in the case of FIGS.
[0036]
In FIG. 4, the dielectric substrate 1, the main conductor layer 3, the side wall through conductor group 4, the end surface through conductor group 5, and the dielectric layer 9 are omitted for convenience of explanation, and the main conductor layer 2 and the high frequency transmission line 6 are omitted. Only the positional relationship among the signal transmission through conductor 7, the protrusion 8, the same-surface ground conductor layer 11, and the ground through conductor group 12 is shown.
[0037]
In this example, as shown in FIG. 4, the high-frequency transmission line 6 and the coplanar ground conductor layer 11 are formed on the dielectric layer 9 located on the upper side of the dielectric waveguide line 10.
[0038]
The connection structure of FIG. 4 shows a preferred embodiment of the present invention, and the upper main conductor layer is formed so as to surround the signal transmission through conductor 7 in a circle in plan view at an interval of ½ or less of the guide wavelength. In this configuration, a plurality of ground through conductor groups 12 electrically connected to 2 are formed in the dielectric layer 9 except under the high-frequency transmission line 6. Thereby, the influence of the external electromagnetic wave with respect to the signal transmission through conductor 7 can be reduced, and the transmission loss in the signal transmission through conductor 7 is reduced, so that the transmission characteristic is good.
[0039]
Further, the electromagnetic wave propagating through the high-frequency transmission line 6 by the connection structure of FIG. 4 propagates through the coaxial line in the signal transmission through conductor 7. At this time, since the propagation mode in the high-frequency transmission line 6 and the coaxial line is the quasi-TEM mode and the TEM mode as the main mode, the propagation mode between the high-frequency transmission line 6 and the signal transmission through conductor 7 is changed. Loss due to conversion can be suppressed. Further, the signal transmission through conductor 7 and the protrusion 8 act as a capacity-loaded monopole antenna, and propagate through the electromagnetic field generated around the signal transmission through conductor 7 and the protrusion 8 and the dielectric waveguide line 10. Since the electromagnetic field is well coupled, the high frequency signal is propagated into the dielectric waveguide line 10 with low loss.
[0040]
Furthermore, in the connection structure of the present invention, the same-surface ground conductor layer 11 is formed on both sides of the high-frequency transmission line 6 with a predetermined interval, and the same-surface ground conductor layer 11 extends so as to surround the end of the high-frequency transmission line 6. It is preferable that the plurality of ground penetrating conductor groups 12 are electrically connected to the same plane ground conductor layer 11. In this case, the signal transmission through conductor 7 can be electrically isolated, and the influence of an external electromagnetic wave on the signal transmission through conductor 7 can be further reduced. As a result, the transmission loss of the high-frequency signal in the signal transmission through conductor 7 is reduced, and the transmission characteristics are excellent.
[0041]
Next, FIG. 7 shows an embodiment of a high-frequency circuit board 50 having a connection structure between the dielectric waveguide line 10 and the high-frequency transmission line 6 according to the present invention. The crack of the dielectric substrate 31 can be avoided by disposing the high-frequency element mounting portion 13 on the front side. That is, when the metal waveguide 40 having the conventional structure shown in FIG. 12 and the dielectric substrate 31 are joined, cracks are likely to occur in the dielectric substrate 31 due to the difference in thermal expansion coefficient between them. In the case of this connection structure, since only the conventionally known multilayering technique of ceramics is used, the thermal expansion between the dielectric substrate 1 on which the dielectric waveguide line 10 is formed and the dielectric layer 9 on which the high-frequency circuit is formed. The difference in the coefficients becomes small, and cracks are hardly generated in the dielectric substrate 1 and the dielectric layer 9. Therefore, the high-frequency circuit board 50 having a connection structure between the dielectric waveguide line 10 of the present invention and the high-frequency transmission line 6 can be easily manufactured at low cost and high reliability.
[0042]
Next, FIG. 8 shows an embodiment of a high frequency device mounting package provided with a lid 14 that covers the high frequency device mounting portion 13 on the high frequency circuit board 50. However, in FIG. 8, a part of the lid body 14 is omitted. The lid 14 is preferably a concave metal body, a concave ceramic, or the like. By covering the mounting portion 13 with the lid body 14, it can be prevented from being affected by interference caused by external electromagnetic waves, and a high-reliability high-frequency element mounting package can be manufactured. If the mounting portion 13 needs to be airtight, the high-frequency circuit board 50 and the lid body 14 may be joined using a solder material.
[0043]
【Example】
Examples of the connection structure between the dielectric waveguide line 10 and the high-frequency transmission line 6 according to the present invention will be described below.
[0044]
The connection structure having the configuration shown in FIG. 1 was configured as follows. First, dielectric constant ε _r A dielectric substrate 1 having a thickness of 1.9 mm and a dielectric waveguide 1 having a longitudinal section of 3.37 mm × 1.69 mm was formed on the dielectric substrate 1. Further, a high-frequency transmission line 6 having an impedance of 50Ω is formed on the upper surface of the dielectric layer 9, and a signal transmission through conductor 7 having a diameter of 0.1 mm is inserted into the dielectric waveguide line 10 from the end thereof. The insertion length was set to 0.91 mm.
[0045]
Further, a circular protrusion 8 having a diameter of 0.3 mm and concentric with the signal transmission through conductor 7 was formed in the dielectric waveguide line 10 of the signal transmission through conductor 7.
[0046]
At this time, the end surface through conductor group 5 is formed at a position of 1.34 mm corresponding to a distance of a quarter of the in-tube wavelength of the high frequency signal of 24 GHz from the transmission through conductor 7 on the side opposite to the signal transmission direction. A short circuit end was formed.
[0047]
The main conductor layer 2 is provided with a hole 2 a so as not to be electrically connected to the signal transmission through conductor 7. Thereby, the sample of the connection structure of the dielectric waveguide line 10 of this invention and the high frequency transmission line 6 was produced.
[0048]
As a comparative example, a comparative sample was produced in the same manner as the above sample except that the protruding portion 8 was not provided.
[0049]
And about these samples, the coupling characteristic between the edge part of the high frequency transmission line 6 and the dielectric waveguide line 10 was analyzed with the electromagnetic field simulator, and each reflection coefficient S11 and transmission coefficient S21 were calculated | required. FIG. 9 shows the results of electrical characteristics of a sample of the connection structure between the dielectric waveguide line 10 and the high-frequency transmission line 6 according to the present invention. FIG. 9 is a graph showing the frequency characteristics of the S parameter. The horizontal axis represents frequency (unit: GHz), and the vertical axis represents S11 and S21 (unit: dB). In FIG. 9, the solid line shows the result of S11 in the example of the present invention, and the dotted line shows the result of S21 in the example of the present invention. In addition, the solid thin line to which the triangle mark is added shows the result of S11 in the comparative example, and the solid thin line to which the x mark is added shows the result of S21 in the comparative example.
[0050]
From FIG. 9, it was found that in the connection structure of the present invention, S11 satisfies about -35 dB and S21 satisfies about -0.3 dB at 24 GHz, and has excellent transmission characteristics.
[0051]
On the other hand, in the connection structure of the comparative example, at 11 GHz, S11 was about -10 dB, and S21 was about -1 dB.
[0052]
In addition, this invention is not limited to the said embodiment and Example, A various change may be added in the range which does not deviate from the summary of this invention.
[0053]
【The invention's effect】
The connection structure between the dielectric waveguide line and the high-frequency transmission line according to the present invention is such that the high-frequency transmission line is a quarter of the in-tube wavelength from the end face of the dielectric waveguide line on which the end face through conductor group is formed. Because it has a signal transmission through conductor extended without being connected to the main conductor layer from the end of the high-frequency transmission line so that the tip is inserted into the dielectric waveguide line at a distance, The loss of the high frequency signal due to the electrical cancellation of the high frequency signal excited by the signal transmission through conductor and radiated into the dielectric substrate and the high frequency signal reflected by the end surface through conductor group. It can be effectively reduced. Therefore, it is possible to efficiently radiate a high-frequency signal forward (on the side opposite to the end surface through conductor group) and to extract it to the outside with low loss.
[0054]
In addition, since the signal transmission through conductor has a circular protrusion formed concentrically with the signal transmission through conductor at a portion located in the dielectric waveguide line, It is possible to reduce the height of the connection structure while maintaining the low-loss electrical characteristics of the connection structure with the high-frequency transmission line. That is, the frequency f excited between the signal transmission through conductor and the main conductor layer is f = 1 / 2π (LC). ^1/2 (L: Reactance amount generated in signal transmission through conductor, C: Capacity generated between signal transmission through conductor and main conductor layer) When the insertion length of the signal transmission through conductor is shortened, L decreases between the signal transmission through conductor and the main conductor layer, and the frequency to be excited tends to shift to a higher frequency side than the frequency to be obtained, but the protruding portion causes a gap between the signal transmission through conductor and the main conductor layer. The generated C can be increased, and the frequency to be excited can be shifted to the low frequency side. As a result, since the product LC value can be kept constant without changing, the frequency f can be maintained at a value to be obtained, and the dielectric can be shortened while maintaining the electrical characteristics of the signal transmission through conductor. The waveguide line can be reduced in height.
[0055]
Thus, according to the present invention, it is possible to easily connect the dielectric waveguide line, the microstrip line, and the coplanar line. In addition, since it can be easily manufactured by using a conventionally known ceramic multilayering technique, a low-cost and highly reliable low-profile coupling structure can be configured.
[0056]
In the connection structure between the dielectric waveguide line and the high-frequency transmission line according to the present invention, the distance between the protrusion and the upper main conductor layer is larger than the distance between the protrusion and the lower main conductor layer. Since it is large, it is possible to effectively suppress the deterioration of transmission characteristics due to the generation of unnecessary stray capacitance between the protruding portion and the conductor positioned above the dielectric waveguide line. That is, since the entire surface of the lower surface of the dielectric waveguide is covered with the main conductor layer, the protruding portion is electrically cut off from the conductor located below the dielectric waveguide. In the main conductor layer immediately above the protrusion, a hole for introducing the signal transmission through conductor into the dielectric waveguide line is formed. At the hole, the protrusion and the dielectric conductor are formed. Since electrical disconnection from the conductor located above the wave guide line is incomplete and unnecessary stray capacitance is likely to occur between them, the distance between the upper main conductor layer and the protruding portion is increased. By doing so, the generation of this stray capacitance can be suppressed.
[0057]
In the connection structure between the dielectric waveguide line and the high-frequency transmission line according to the present invention, since the protruding portion is located above the lower end of the signal transmission through conductor, the reflection loss at the lower end of the signal transmission through conductor. Can be effectively suppressed and the transmission characteristics can be made very good. That is, if a protruding portion is provided at the lower end of the signal transmission through conductor, the diameter of the lower end of the signal transmission through conductor increases rapidly, so that the loss of the high-frequency signal reflected at the lower end tends to become very large. By providing the diameter of the signal transmission through conductor without providing the protrusions, the reflection loss can be effectively suppressed.
[0058]
The high-frequency circuit board of the present invention has a low loss by providing a dielectric substrate with a connection structure between the dielectric waveguide line and the high-frequency transmission line configured as described above and a mounting portion for mounting the high-frequency element. Therefore, it is easy to reduce the thickness.
[0059]
The high-frequency element mounting package of the present invention provides a thin high-frequency element mounting package having low-loss electrical characteristics by attaching a lid so as to cover the mounting portion of the high-frequency circuit board having the above configuration. be able to.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an example of an embodiment of a connection structure between a dielectric waveguide line and a high-frequency transmission line according to the present invention.
FIG. 2 is a plan view of the connection structure of FIG.
3 is a cross-sectional view taken along line XX ′ of the connection structure of FIG.
FIG. 4 is a perspective view showing another example of the embodiment of the connection structure between the dielectric waveguide line and the high-frequency transmission line according to the present invention.
FIG. 5 is a plan view of the connection structure of FIG.
6 is a cross-sectional view taken along the line YY ′ of the connection structure of FIG. 4;
FIG. 7 is a perspective view showing an example of an embodiment of a high-frequency circuit board having a connection structure between a dielectric waveguide line and a high-frequency transmission line according to the present invention.
FIG. 8 is a perspective view showing an example of an embodiment of a high frequency device mounting package having a connection structure between a dielectric waveguide line and a high frequency transmission line according to the present invention.
FIG. 9 is a diagram showing a measurement result of an S parameter for a connection structure between a dielectric waveguide line and a high-frequency transmission line according to the present invention.
FIG. 10 is a perspective view showing a connection structure between a conventional dielectric waveguide line and a high-frequency transmission line.
11 is a cross-sectional view taken along the line ZZ ′ of the connection structure of FIG.
FIG. 12 is a perspective view showing a connection structure between a conventional metal waveguide and a signal transmission through-conductor pin.
[Explanation of symbols]
1: Dielectric substrate
2, 3: Main conductor layer
4: Side wall through conductor group
5: Through conductor group for end face
6: High-frequency transmission line
7: Through conductor for signal transmission
8: Protruding part
9: Dielectric layer
10: Dielectric waveguide line
11: Coplanar ground conductor layer
12: Grounding through conductor group
13: Mounted part
14: Lid
50: High frequency circuit board

Claims (5)

A pair of main conductor layers sandwiching the dielectric substrate from above and below are electrically connected between the pair of main conductor layers formed in the transmission direction of the high-frequency signal at a repetition interval of less than half of the guide wavelength of the high-frequency signal. A pair of side wall through conductor groups connected to each other, and the pair of main leads formed at one end of the side wall through conductor groups at one end of the two side wall through conductor groups at the repetition interval. The transmission through the dielectric layer on either the upper or lower side of the dielectric waveguide line for transmitting the high-frequency signal by the region surrounded by the end surface through conductor group that electrically connects the body layers A connection structure between a dielectric waveguide line and a high-frequency transmission line for coupling a high-frequency transmission line arranged in parallel to the direction, wherein the through-conductor group for the end face is formed in the high-frequency transmission line The guide wavelength from the end face of the dielectric waveguide line A signal transmission through conductor extending from the end of the high-frequency transmission line without being connected to the main conductor layer so that the tip is inserted into the dielectric waveguide line having a quarter distance The signal transmission through conductor is characterized in that a circular protrusion is formed concentrically with the signal transmission through conductor at a portion located in the dielectric waveguide line. A connection structure between a dielectric waveguide line and a high-frequency transmission line. 2. The dielectric waveguide according to claim 1, wherein a distance between the protruding portion and the upper main conductor layer is larger than a distance between the lower main conductor layer and the lower main conductor layer. Connection structure with transmission line. 3. The connection structure between a dielectric waveguide line and a high-frequency transmission line according to claim 1, wherein the protruding portion is located above a lower end of the signal transmission through conductor. A connection structure between the dielectric waveguide line according to any one of claims 1 to 3 and a high-frequency transmission line, and a mounting portion for mounting a high-frequency element are provided on the dielectric substrate. A high-frequency circuit board. 5. A high frequency device mounting package, wherein a lid is attached to cover the mounting portion of the high frequency circuit board according to claim 4.

Images