JP2001230608A - Dielectric line - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dielectric line, where improves accuracy for working dielectric materials and for attaching a conductor film is improved and which is suitable for mass-production. SOLUTION: Conductor films 1 and 2 are formed on the front and rear sides of a silicon substrate 3, a through-hole 4 is formed on the silicon substrate 3 by dry etching, while changing hole density and a dielectric waveguide is composed of an electromagnetic wave propagating part 5 and an electromagnetic wave shielding part 6, by changing the hole density of the through-hole 4, so that the dielectric line with the reduced dispersion of characteristics and improved in mass-productivity can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a dielectric line applied to a millimeter wave / microwave band, and a radio apparatus using the same.

[0002]

2. Description of the Related Art Conventionally, in the above-described dielectric line, for example, Japanese Patent Application Laid-Open No. 57-166701 (Patent No. 142)
No. 5546) is known. Hereinafter, the conventional dielectric line will be described with reference to FIG. FIG. 9 is a sectional perspective view showing the configuration of a conventional dielectric line. In FIG. 9, a dielectric material 1 is interposed between a pair of upper and lower conductor plates 101 and 102 arranged in parallel with each other.
03 forms a transmission path 104, and its conductor plate spacing a
Is の of the wavelength of the electromagnetic wave propagating along the transmission line 104
It is set to be as follows.

[0003]

However, in the above-mentioned conventional dielectric line, there is a problem that it is difficult to mass-produce while maintaining the processing accuracy of the dielectric material and the mounting accuracy of the upper and lower conductor plates. SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and provides a dielectric line having a low-loss structure suitable for mass production.

[0004]

According to the present invention, there is provided a dielectric line comprising a silicon substrate having upper and lower conductor films mounted on a front surface and a rear surface, and having a large number of through holes formed between the upper and lower conductor films. An electromagnetic wave blocking portion and an electromagnetic wave propagating portion are provided by a change in hole density of the through hole formed in the silicon substrate, and the electromagnetic wave is propagated through the electromagnetic wave propagating portion. With this configuration, the height direction of the transmission line can be realized with high accuracy, and a loss due to a discontinuous portion such as a gap between the upper and lower conductors and the dielectric does not occur.
By forming through-holes in the dielectric substrate with high precision, and in the horizontal direction, only through-hole positioning accuracy by dry etching is used. Thus, a low-loss dielectric line can be realized.

In the dielectric line according to the present invention, the permittivity of the silicon substrate is εr, and the height h of the silicon substrate is h.
Was 1/2 or less of 1/2 or more and the free-space wavelength .lambda.0 propagation wavelength λ1 in the electromagnetic propagation portion, the filling rate RX of electromagnetic wave shielding unit ^{RX = (λ0 2/4 /} h 2 -1) / (εr- 1) In the following, the interval between through holes is set to 1/10 of the free space wavelength λ0
It is configured to be formed as follows. With this configuration, radio waves can be efficiently confined in the dielectric, so that a low-loss dielectric line with excellent mass productivity can be realized.

The dielectric waveguide according to the present invention has a configuration in which slots are formed at arbitrary intervals in both or one of the upper and lower conductor films above and below the electromagnetic wave propagation portion of the silicon substrate. With this configuration, by setting the width and interval of the slot formed in the conductor film to appropriate values, it is possible to give frequency selectivity to radio waves that can be confined in the dielectric, and to achieve low mass production. A dielectric line having loss frequency selectivity can be realized.

In the dielectric line according to the present invention, an active element mount on which a bias circuit and an electrode wiring for mounting an active element are formed is formed, and a through hole for inserting the active element mount is provided in the silicon substrate. Is provided with an active element. With this configuration,
An active circuit using a low-loss dielectric line can be realized.

The dielectric line according to the present invention includes a slot formed in the upper conductive film on the electromagnetic wave propagation portion, a dielectric thin film laminated on the upper conductive film, and a dielectric thin film formed on the dielectric thin film. And an active element mounted on the wiring layer, and the active element is mounted on the dielectric thin film. With this configuration, the dielectric line and the active circuit can be integrally formed with high precision.

A radio base station apparatus according to the present invention has a configuration including the dielectric line according to any one of claims 1 to 5. With this configuration, it is possible to achieve higher performance and lower cost of the wireless base station device.

The wireless terminal device according to the present invention is characterized in that
A dielectric line according to any one of (1) to (5) is provided. With this configuration, it is possible to realize higher performance and lower cost of the wireless terminal device.

The wireless measuring device according to the present invention is characterized in that
A dielectric line according to any one of (1) to (5) is provided. With this configuration, it is possible to achieve high performance and low cost of the wireless measurement device.

Here, an outline of the present invention configured to achieve the object of the present invention will be described. The present invention provides a spatial distribution in the dielectric constant of a dielectric substrate by forming a plurality of through holes having different hole densities in a dielectric substrate, and forming conductor films above and below the dielectric substrate. It was configured to be a signal transmission path. According to this configuration, the height direction of the transmission line can be realized with high accuracy by laminating the conductor film on the dielectric substrate having high thickness accuracy, and the distance between the upper and lower conductors and the dielectric can be realized. There is no loss due to discontinuities such as gaps. Further, since the accuracy in the horizontal direction is determined only by the positional accuracy of the through-hole by dry etching, it can be accurately arranged at an arbitrary position. By the above method, a low-loss dielectric line excellent in mass productivity can be realized.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, first to fourth embodiments of the present invention will be described in detail with reference to FIGS. (First Embodiment) First, a dielectric line according to a first embodiment of the present invention will be described with reference to a perspective view of the dielectric line shown in FIG. In FIG. 1, an upper conductive film 1 and a lower conductive film 2 are respectively laminated on upper and lower (or front and back) surfaces of a silicon substrate 3, and through holes 4 are formed in the silicon substrate 3 by dry etching. The silicon substrate 3 changes the density of the through holes 4, and a portion having a low density of the through holes 4 is used as an electromagnetic wave propagation portion 5 as a dielectric waveguide.
A portion of the through hole 4 where the density is high is defined as an electromagnetic wave blocking portion 6. The propagation direction of the electromagnetic wave is indicated by an arrow 7.

Next, with reference to FIG. 1, the configuration of the dielectric line according to the first embodiment of the present invention will be described in more detail. The silicon substrate 3 is a dielectric substrate made of a dielectric material used in a semiconductor process, and has a thickness accuracy of ± 10 μm.
m can be easily realized, and a conductive film having a thickness of several μm can be laminated on the front and back surfaces by sputtering, plating, or the like. The silicon substrate 3 needs to have an appropriate thickness so that electromagnetic waves can be transmitted through the electromagnetic wave propagation unit 5. The thickness is, for example, 以上 or more of the wavelength λ1 in silicon and so that the electromagnetic wave does not propagate through the electromagnetic wave blocking unit 6.
It is set to be equal to or less than 1/2 of the free space wavelength λ0. That is, assuming that the dielectric constant of silicon is 13.1 in the 60 GHz band, the distance between the upper conductive film and the lower conductive film is 0.7 mm or more, which is の of the wavelength of 1.4 mm in silicon, and free space wavelength. λ0 or less, that is, 2.5 mm or less.

In the electromagnetic wave blocking portion 6, it is necessary to determine the distance between the through holes so that the electromagnetic wave propagating portion 5 becomes a complete electric wall. The interval between the through holes is, for example, 1/10 or less of the wavelength λ1 in silicon. According to this condition,
The spacing between the through holes is 140 μm. On the other hand, when the distance between the upper conductor film 1 and the lower conductor film 2 is determined, the electromagnetic wave blocking unit 6
The maximum filling rate RX of the dielectric material in the electromagnetic wave blocking unit 6 necessary for preventing the electromagnetic wave from propagating to the outside is determined. Its value is given by the following equation. ^{RX = (λ0 2/4 /} h 2 -1) / (εr1) the dielectric constant of the electromagnetic wave shielding portion 6 at this time and .epsilon.r1.

Under the above conditions, if the distance between the upper and lower conductor films is set to 0.8 mm, the maximum value of the filling rate RX required in the electromagnetic wave blocking section 6 is 0.56. Therefore, assuming that the filling rate RX in the electromagnetic wave blocking unit 6 is 0.1, the radius of the through hole 4 is 74 μm. The width of the electromagnetic wave propagation part 5 is
In order to make the propagation mode in the electromagnetic wave propagation unit 5 a single LSM01 mode, 0.4 to (free space wavelength λ0) / (伝 播 (dielectric constant of propagation unit εr / dielectric constant of blocking unit εr1-1)) is used.
It is desirable that the width of the electromagnetic wave propagation part 5 is about 1.2 mm, which is 0.6 times.

Next, the operation of the dielectric line according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a cross-sectional view of a conventional dielectric line, and FIG. 3 is a cross-sectional view showing an operation of the dielectric line according to the first embodiment of the present invention shown in FIG. First, the configurations of the dielectric line shown in FIG. 2 and the dielectric line shown in FIG. 3 will be described. A dielectric strip 203 is provided between the upper and lower metal flat plates 201 and 202 serving as the upper and lower ground conductors. Also,
A silicon substrate 303 having a through hole 304 is provided between the upper and lower conductor films 301 and 302 shown in FIG. The dielectric waveguides shown in FIGS. 2 and 3 respectively include electromagnetic wave propagation units 205 and 305 and electromagnetic wave blocking units 206 and 30.
6 and the polarization directions 208, 308 of the electric field are indicated by respective arrows.

In contrast to the conventional dielectric line shown in FIG.
The operation of the dielectric line according to the first embodiment of the present invention will be described. In general, an electromagnetic wave polarized parallel to the metal flat plates 201 and 202 is intercepted and propagates between two metal flat plates 201 and 202 placed in parallel at an interval of 1/2 or less of the wavelength λ0 of free space. Can not do. However, when the dielectric strip 203 is inserted between the metal plates 201 and 202, the propagation wavelength is shortened inside the dielectric strip 203. Therefore, the cutoff state is released, and the electromagnetic wave having the polarization direction 208 indicated by the arrow is propagated. Similarly, as shown in FIG. 3, the upper and lower conductor films 301, 3
When a myriad of through-holes 304 are provided by dry etching on a silicon substrate
Since the effective permittivity of this portion is reduced and the distance between the upper and lower conductive films 301 and 302 becomes 以下 or less of the propagation wavelength, the electromagnetic wave blocking portion 306 through which the electromagnetic wave does not propagate is formed, and the through hole of the silicon substrate 303 is formed. The portion without 304 is the electromagnetic wave propagation unit 305. Therefore, the structure of the dielectric line according to the first embodiment of the present invention also exhibits the same operation as the conventional dielectric line shown in FIG.

Next, a method for manufacturing a dielectric line according to the first embodiment of the present invention will be described with reference to FIG. On the upper and lower sides of the silicon substrate 303, upper and lower conductive films 301 and 302 having a thickness equal to or greater than the skin depth are formed by, for example, sputtering or plating. And the through hole 30
4 and upper and lower conductor films 301 and 302
After removing both or one of them, an etching mask is provided thereon, and the entire silicon substrate 303 is dry-etched. Thereby, the through hole 30 is formed in the silicon substrate 303.
4 is formed with high precision and easily.

As described above, by processing the dielectric waveguide, it is possible to form a dielectric waveguide in which an electromagnetic wave propagates in a single dielectric.
03 (FIG. 2) is sandwiched between the upper and lower conductor plates, and is compared with a conventional dielectric line in which a nut or an adhesive is used to fix the upper and lower conductor films 301 and 302 and the silicon substrate as a dielectric. The upper and lower conductor films 3 serving as ground conductors do not generate a minute gap between them.
01 and 302 can be arranged with high precision. Also,
In contrast to the processing method of arranging the dielectric strip 203, by realizing a dielectric waveguide by drilling, the position accuracy of the electromagnetic wave propagation unit 305 is improved, and the error in characteristics is reduced by not using an adhesive, Productivity can be improved.

As described above, according to the first embodiment of the present invention, a large number of through holes are formed in a silicon substrate on which a conductor film is laminated by dry etching, and the hole density of the electromagnetic wave propagation portion and the electromagnetic wave blocking portion is reduced. By applying a dielectric line processing method with high productivity, which realizes a dielectric waveguide by changing the dielectric waveguide, it is possible to form the dielectric line with low loss and high accuracy.

(Second Embodiment) Next, a dielectric line according to a second embodiment of the present invention will be described with reference to a perspective view of the dielectric line shown in FIG. 4 differs from the dielectric line shown in FIG. 1 in that a slot 401 is formed in both or one of the upper and lower conductor films 1 and 2 of the electromagnetic wave propagation unit 5. In FIG. 4, the radius and the interval of the slot 401 are obtained from the dispersion of the propagating electromagnetic wave by applying the band theory. For example, by setting the interval between the slots 401 to 30 to 80% of the guide wavelength, a desired frequency band can be set as a cutoff band. By forming the slots 401 in both or one of the upper and lower conductor films 1 and 2 in this manner, a low-loss dielectric line having selectivity of a frequency band through which an electromagnetic wave passes can be realized at low cost. Can be.

Third Embodiment Next, a third embodiment of the present invention will be described with reference to a perspective view of a dielectric line shown in FIG. 5 and a sectional view of a diode mount on which a diode is mounted as shown in FIG. Will be described. The perspective view of the dielectric line shown in FIG. 5 shows the mounting method of the active device according to the third embodiment of the present invention, and the cross-sectional view shown in FIG. 6 is a switch inserted into the horizontal through hole 516 shown in FIG. 2 shows a cross section of a diode mount 601 on which a mounting diode is mounted.

In FIG. 5, the upper and lower conductor films 50
Reference numerals 1 and 502 are respectively laminated on the upper and lower surfaces of the silicon substrate 503. In the recon substrate 503, an electromagnetic wave blocking region 510 for blocking electromagnetic waves, an electromagnetic wave propagating region 511 for propagating electromagnetic waves, a second electromagnetic wave propagating region 512, a region 513 having no through hole, a matching circuit portion 514, A semi-rigid cable 515 for bias and a through hole 516 formed in the silicon substrate 503 for inserting the diode mount 601 from the lateral direction are formed. In FIG. 6, a diode mount 6 as an active element mount is shown.
01 is the switching diode 602 and the dielectric substrate 6
03, a patch antenna 604, and a bias choke circuit 605.

Next, referring to FIGS. 5 and 6, the structure of the dielectric line according to the third embodiment of the present invention will be described in further detail. Similarly to the first embodiment of the present invention, the hole density of the electromagnetic wave blocking region 510 and the hole density of the electromagnetic wave propagating region 511 with respect to the silicon substrate 503 having a through hole forming the electromagnetic wave blocking region 510 and the electromagnetic wave propagating region 511 are determined. Second electromagnetic wave propagation region 512 having an intermediate hole density
And a region 513 in which a through-hole is not formed, which is referred to as a matching circuit portion 514. A through-hole 516 for inserting the diode mount 601 from the lateral direction is formed in the silicon substrate 503.

The diode mount 601 shown in FIG.
It is made of a dielectric substrate 603 made of Teflon or the like. On one surface, an on / off switching signal is transmitted to a patch antenna 604 which propagates an electromagnetic field propagating in the dielectric waveguide to a line on the dielectric substrate 603, and a diode 602. It has a bias choke circuit 605 to be added. Bias choke circuit 605
Is input using a semi-rigid cable 515.

The height of the diode mount 601 is the same as the distance between the upper and lower conductive films 501 and 502 in order to prevent unnecessary radiation.
Is designed to be a band rejection filter for the operating frequency band. Under these conditions, for example, the height of the diode mount 605 is 2.0 mm, and when a Teflon substrate having a substrate thickness of 0.3 mm and a dielectric constant of 2.04 is used as the dielectric substrate 603, a band of 60 GHz band is used. It is preferable that the width of the electrode of the bias choke circuit 605 is about 1 mm and the height is about 1.2 mm and 0.1 mm so as to form a rejection filter.

The dielectric line according to the third embodiment of the present invention described above has a structure in which an active element mount on which an active element is mounted is manufactured separately from the dielectric line, and is mounted on the dielectric line after the manufacture. By doing so, a low-loss dielectric line with an active element can be easily configured.

In the above description, a diode mount which is a switch circuit using a diode as an active element mount has been described. However, other active elements such as a single transistor or a functional IC may be used as an active device. It can be implemented similarly.

(Embodiment 4) Next, a dielectric line according to a fourth embodiment of the present invention will be described in detail with reference to FIGS. FIG. 7 shows an operation of the dielectric line according to the fourth embodiment of the present invention, and FIG. 8 is a block diagram of a receiving module which is an example of the circuit shown in FIG.
7, an upper conductor film 701 and a lower conductor film 702 are shown.
Are laminated on both upper and lower surfaces of the silicon substrate 703, respectively.
Through holes 4 are formed in the silicon substrate 3 by dry etching. According to the density of the through-holes 704 in the silicon substrate 3, a portion having a low density of the through-holes 704 is defined as an electromagnetic wave propagation portion 705, and a portion having a high density of the through-holes 704 is defined as an electromagnetic wave blocking portion 706. A slot 70 for electromagnetic field coupling is provided at a position of the upper conductor film 701 facing the electromagnetic wave propagation portion 705.
8, and a dielectric thin film 709 on which an active element 711 and a wiring conductor 710 are mounted is provided on the upper conductor film 701.

The receiving module shown in FIG. 8 is arranged between a mounting portion 805 mounted on a dielectric thin film 709 on an upper conductor film 701 shown in FIG. 7, and between the upper conductor film 701 and the lower conductor film 702. And a dielectric line portion 806. The mounting portion 805 has a low-noise amplifier 801, a local amplifier 803, and a mixer 804, and the dielectric line portion 806 has a bandpass filter 802.

FIG. 7 is different from the first embodiment in that a slot 708 of a predetermined size is provided in an upper conductive film 701 on an electromagnetic wave propagation portion 705 and a dielectric thin film 709 is formed.
And the wiring conductor 710 are laminated, and a signal in the dielectric waveguide is taken out to the wiring conductor 710 through the slot 708. The active element 711 is mounted on the wiring conductor 710.

When the receiving module shown in FIG. 8 is constructed using the dielectric line according to the fourth embodiment of the present invention shown in FIG. 7, the low noise amplifier 801 and the local amplifier 80
The active element and the power supply circuit 3 are provided on the upper conductive film 7 shown in FIG.
The band-pass filter 802 and the line routing portion, which are arranged on the dielectric thin film 709 on which the lower conductor film 701 is required to have a low loss property, have the upper conductor film 701 and the lower conductor film 7 shown in FIG.
02 in the dielectric line portion disposed between the first and second lines.
The connection between the mounting portion 805 disposed on the upper side of the upper conductor film 701 and the dielectric line portion 806 disposed between the upper and lower conductor films 701 and 702 is performed by the electromagnetic field coupling slot 708 shown in FIG. It is performed by

The dielectric waveguide according to the fourth embodiment of the present invention is obtained by laminating a dielectric thin film and a wiring conductor on a silicon substrate on which a dielectric waveguide is formed, and mounting an active element thereon. A low-loss dielectric line that can be easily integrated with an element can be easily configured.

[0035]

The dielectric waveguide according to the present invention is constructed as described above. In particular, a large number of through holes are formed in a silicon substrate by dry etching, and the electromagnetic wave propagation portion and the electromagnetic wave are formed by changing the hole density of the through holes. By constituting the dielectric waveguide by forming the cut-off portion, it is possible to realize a low-loss dielectric line with less variation in characteristics and excellent mass productivity.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a dielectric line according to a first embodiment of the present invention;

FIG. 2 is a sectional view showing a configuration of a conventional dielectric line,

FIG. 3 is a sectional view showing an operation of the dielectric line according to the first embodiment of the present invention shown in FIG. 1;

FIG. 4 is a perspective view showing a configuration of a dielectric line according to a second embodiment of the present invention;

FIG. 5 is a perspective view showing a configuration of a dielectric line according to a third embodiment of the present invention;

FIG. 6 is a sectional view of a diode mount when a switching diode used for the dielectric line of FIG. 5 is mounted;

FIG. 7 is a cross-sectional view of a dielectric line with an active element showing a configuration of a fourth embodiment of the present invention;

FIG. 8 is a block diagram of a receiving module of the dielectric line shown in FIG. 7;

FIG. 9 is a perspective view showing a configuration of a conventional dielectric line.

[Explanation of symbols]

1, 301, 501, 701 Upper conductor film 2, 302, 502, 702 Lower conductor film 3, 303, 503, 703 Silicon substrate 4 Through hole formed in silicon by dry etching 5, 305, 705 Electromagnetic wave propagation Part 6, 306, 706 Electromagnetic wave blocking part 7 Arrow indicating propagation direction of electromagnetic wave 201 Upper metal flat plate 202 Lower metal flat plate 203 Dielectric strip 205 Electromagnetic wave propagating unit in conventional dielectric line 206 Electromagnetic wave blocking unit in conventional dielectric line 208 Polarization direction of electric field in conventional dielectric line 304 Through hole drilled in silicon substrate 308 Polarization direction of electric field 401 Slot 510 Electromagnetic wave blocking region in silicon substrate 503 511 Electromagnetic wave propagation region 512 Second electromagnetic wave propagation region 513 Penetration Non-drilled area 514 Matching circuit section 515 Semi-rigid cable for bias 516 Through hole opened in silicon substrate 503 from lateral direction 601 Diode mount 602 Diode for switch 603 Dielectric substrate 604 Patch antenna 605 Bias choke circuit 704 Through hole formed in silicon substrate 703 708 For electromagnetic field coupling Slot 709 Dielectric thin film 710 Wiring conductor 711 Active element 801 Low noise amplifier 802 Bandpass filter 803 Local amplifier 804 Mixer 805 Mounting part arranged on dielectric thin film 701 806 Arranged between upper and lower conductor films 701 and 702 Dielectric line part

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Kazuaki Takahashi 3-10-1 Higashi-Mita, Tama-ku, Kawasaki-shi, Kanagawa F-term in Matsushita Giken Co., Ltd. 5J014 HA06

Claims (8)

[Claims] 1. A silicon substrate having upper and lower conductor films mounted on a front surface and a rear surface, and having a plurality of through holes formed between the upper and lower conductor films, wherein the through holes formed in the silicon substrate are provided. A dielectric line, comprising: an electromagnetic wave blocking portion and an electromagnetic wave propagating portion provided by a change in density, and an electromagnetic wave is propagated through the electromagnetic wave propagating portion. 2. The electromagnetic wave blocking section, wherein the dielectric constant of the silicon substrate is εr, the height h of the silicon substrate is 以上 of the propagation wavelength λ1 in the electromagnetic wave propagation section and 以下 of the free space wavelength λ0. the filling ratio RX to ^{RX = (λ0 2/4 /} h 2 -1) / 1/10 of (εr-1) below and to the free space wavelength intervals of the through hole .lambda.0
2. The dielectric waveguide according to claim 1, wherein the dielectric waveguide is formed as follows. 3. The dielectric line according to claim 1, wherein slots are formed at arbitrary intervals in both or one of the upper and lower conductor films above and below the electromagnetic wave propagation portion of the silicon substrate. 4. An active element mount on which a bias circuit and an electrode wiring for mounting an active element are formed, a through hole for inserting the active element mount is provided in the silicon substrate, and an active element is provided in the through hole. The dielectric line according to claim 1, wherein: 5. A slot formed in the upper conductor film above the electromagnetic wave propagation portion, a dielectric thin film laminated on the upper conductor film, a wiring layer formed on the dielectric thin film, 2. The dielectric line according to claim 1, further comprising: an active element mounted on a wiring layer, wherein the active element is provided on the dielectric thin film. 6. A radio base station apparatus comprising the dielectric line according to claim 1. 7. A wireless terminal device comprising the dielectric line according to claim 1. 8. A wireless measuring device comprising the dielectric line according to claim 1.