JP2010118857A - Transmission line using integrated waveguide - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission line using an integrated waveguide for widening the frequency band used in the transmission line. <P>SOLUTION: A first element 10U includes a first dielectric substrate 11U, a first conductor layer 13U formed on the first surface, a second conductor layer 19U formed on the second surface, a first shorted wall 24U provided along each side of the rectangular shape except for the part connected to the input signal line on the first conductor layer and formed in the side opposite to the side connecting the input signal line to electrically connect the first conductor layer and the second conductor layer through the first dielectric substrate, a first conductor member formed of a couple of parallel first sidewalls 22U orthogonally crossing the first shorted wall, and a first slot 25U provided in the second conductor layer on the side of the input signal line at the location of 1/4 of the wavelength in the waveguide from the first terminating wall. In the first slot, the conductor layer is cut away in the width which is narrower than the interval of the couple of first sidewalls and is perpendicular to the signal transmitting direction. A waveguide 56 is also included to connect the first slot 25U and a second slot 25D of a second element 10D having the similar structure which are arranged in parallel. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a transmission line having a wide bandwidth and low loss, in which slots are provided in two integrated waveguides and the slots are coupled by a waveguide.

  Patent Document 1 below discloses a waveguide antenna in which a slot is provided on a wall surface of a waveguide and a radio wave is radiated or received from the slot. Patent Document 2 discloses a linear transmission line sandwiched between two dielectric films, a rectangular waveguide for propagating radio waves in a direction perpendicular to the dielectric film, and the conductivity of the rectangular waveguide. A conversion device is disclosed in which a slit is provided in a lid at a position ¼ of the guide wavelength from the open end of the transmission line in a direction perpendicular to the transmission line. Further, Patent Document 3 discloses a dielectric waveguide in which a slot is provided, a metal plate that is aligned with the slot and has a through hole that is slightly larger than the slot is joined to the dielectric waveguide. A wave tube antenna is disclosed.

Japanese Patent Laid-Open No. 3-7406 JP 2002-76724 A Japanese Patent No. 3824998

  On the other hand, in radar, in order to accurately measure a distance using a short pulse signal, the transmission band of the signal on the transmission line needs to be an ultra-wide band (UWB). However, with the transmission line disclosed in Patent Documents 1 to 3 described above, it has been difficult to increase the bandwidth. As shown in the characteristics of FIG. 4 of Patent Document 2, the bandwidth that generates a return loss of 15 dB or more is about 0.3 GHz, and the bandwidth that generates a return loss of 10 dB or more is about 0.6 GHz. The bandwidth used was narrow.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to widen a high-frequency transmission line.

The first invention relates to a transmission line using an integrated waveguide,
A first dielectric substrate having a first surface as an upper surface and a second surface as a lower surface, a first conductor layer formed on the first surface, and a second conductor formed on the second surface The first conductor layer and the first conductor layer are provided along each side of the rectangular shape, excluding a portion connected to the input signal line, on the first conductor layer, and through the first dielectric substrate. A first short-circuit wall formed on a side opposite to the side to which the input signal line is connected and the two conductor layers electrically connected, and two first side walls parallel to the first short-side wall; The conductive member and the second conductor layer are provided on the input signal line side at a position 1/4 of the guide wavelength from the first short-circuit wall, and are narrower than the distance between the two first side walls and perpendicular to the signal propagation direction. A first slot in which the conductor layer is cut out by a width,
A second dielectric substrate having a third surface that is an upper surface and a fourth surface that is a lower surface and is a surface close to the second surface, and is provided in parallel with the first dielectric substrate; Each of the rectangular shapes except for the third conductor layer formed on the surface, the fourth conductor layer formed on the fourth surface, and the portion connected to the output signal line on the third conductor layer. Provided along the side, electrically connecting the third conductor layer and the fourth conductor layer through the second dielectric substrate, and formed on the side opposite to the side to which the output signal line is connected. A second conducting member comprising the second short-circuit wall and two parallel second side walls perpendicular to the second short-circuit wall, and an output signal at a position of 1/4 of the in-tube wavelength from the second short-circuit wall in the fourth conductor layer. A second slot provided on the line side and having a conductor layer cut away by a width that is narrower than the distance between the two second side walls and perpendicular to the signal propagation direction; A first dielectric substrate and a second dielectric substrate are arranged so that the lot and the second slot are parallel to each other, and a waveguide connecting the first slot and the second slot is provided inside. It is a transmission line characterized by having a formed base.

  In the present invention, the first integrated waveguide is constituted by the first dielectric substrate, the first conductor layer, the second conductor layer, and the first conductive member. The second dielectric substrate, the third conductor layer, the fourth conductor layer, and the second conductive member constitute a second integrated waveguide. The first integrated waveguide and the second integrated waveguide are arranged in parallel. A first slot is provided in the second conductor layer of the first integrated waveguide, and a second slot is provided in the fourth conductor layer of the second integrated waveguide. The first slot and the second slot are provided in parallel, and both are connected by a waveguide provided inside the base. The first slot is provided at a position 1/4 of the guide wavelength of the reference frequency from the first short-circuit wall of the first integrated waveguide, and the second slot is the second of the second integrated waveguide. It is provided at a position of 1/4 of the in-tube wavelength from the short-circuit wall. Therefore, the first and second slots are antinodes of the reference frequency and become resonance points at the first frequency of the reference frequency. Therefore, at this resonance frequency, a signal propagates from the first integrated waveguide to the second integrated waveguide with the least loss. In addition, since the periphery of the outline of the first slot and the second slot is a conductor, the electric field becomes zero on the two sides that determine the width of the slot, and is parallel to the first conductor layer and the second conductor layer. Thus, it is excited in the direction of signal propagation. At this time, the resonating second frequency is different from the basic first frequency. Therefore, by making the second frequency slightly different from the first frequency, bimodal resonance is obtained, and in the wide band without loss, the first integrated waveguide to the second integrated waveguide. Can transmit a signal.

  In the above invention, the first slot and the second slot only need to be in a parallel positional relationship. When the slot is rectangular, it is desirable that the long sides are parallel, but not necessarily parallel. good. In addition, although it is desirable that the positions of the long sides of the first slot and the second slot in the propagation direction of the signals match, it is not always necessary to match. When the directions of the long sides of the first slot and the second slot coincide with the positions, the waveguide formed inside the base is a rectangular parallelepiped. When the long sides of the two slots are parallel and the positions do not match, the waveguide is constituted by a skewed rectangular waveguide. Further, when the positions of the long sides of the two slots coincide and the directions are not parallel, the waveguide is formed of a rectangular waveguide twisted around an axis perpendicular to the first dielectric substrate. Further, when the positions of the long sides of the two slots are not coincident and not parallel, the waveguide is constituted by a rectangular waveguide twisted around an axis oblique to the first dielectric substrate. The Further, the first conductive member and the second conductive member are preferably formed by a large number of conductive via holes. In this case, the arrangement interval of the via holes is made shorter than the cutoff wavelength. However, these conductive members may be configured by filling a conductor in a linear continuous groove instead of the arrangement of a plurality of via holes. Further, the waveguide may have a diaphragm portion in which the interval between the short sides of the waveguide is narrow. The transmission characteristics can be improved by the short side width of the diaphragm.

Furthermore, the first conductor layer is
A first signal line connected to the input signal line formed on the first surface, and a first portion of the first conductor layer formed on both sides of the first signal line and electrically connected to the second conductor layer A first coplanar portion comprising: a first dielectric that is connected to the first coplanar portion, the first signal line passes through the central portion, and the first conductor layer is missing in the width direction perpendicular to the signal transmission direction. And a first exposed portion where the surface of the substrate is exposed.

Furthermore, the third conductor layer is
A second signal line connected to the output signal line formed on the third surface, and a first part of the third conductor layer formed on both sides of the second signal line and electrically connected to the fourth conductor layer A second coplanar portion comprising: a second coplanar portion; a second signal line passing through the central portion; and a third conductor layer missing in a width direction perpendicular to the signal transmission direction And a second exposed portion where the surface of the substrate is exposed.

In the above invention, the input signal line and the output signal line may be a microstrip line or a coplanar line. Further, signal input and output may be performed with the first integrated waveguide and the second integrated waveguide. The input signal line may be directly connected to the first conductor layer of the first integrated waveguide, and the output signal line may be directly connected to the third conductor layer of the second integrated waveguide. Even if it is directly connected, mode conversion is performed. By providing the coplanar part and the exposed part as in the third and fourth inventions, the efficiency of mode conversion is improved. The electromagnetic field mode in the microstrip line or coplanar line is a quasi-TEM mode (a mode close to the TEM mode). In the integrated waveguide, the fundamental mode is the TE ₁₀ mode. Therefore, since the signal propagates from the input signal line toward the first integrated waveguide, the electromagnetic field mode is converted from the TEM mode to the TE ₁₀ mode in the first slot portion. Further, since the signal propagates from the second integrated waveguide toward the output signal line, the electromagnetic field mode is converted from the TE ₁₀ mode to the TEM mode in the second slot portion.

  In the present invention, the first frequency that resonates is determined according to the distance from the first short-circuit wall to the first slot and the distance from the second short-circuit wall to the second slot that is equal to this distance. Further, the resonance frequency in the plane of the first slot and the second slot is a second frequency different from the first frequency because the width and the dielectric constant of the portion are different from the dielectric constant of the dielectric substrate. . By slightly changing the second frequency with respect to the first frequency, bimodal resonance characteristics can be obtained, and resonance in a wide range of frequencies can be obtained. Thereby, the transmission band of the transmission line of the present invention can be widened.

  Hereinafter, the present invention will be described based on specific examples, but the present invention is not limited to the following examples.

  1 is a perspective view of a transmission line 100 according to a specific embodiment of the present invention, FIG. 2 is a plan view of a first element 10U, FIG. 3 is a plan view of a second element 10D, and FIG. 4 is a transmission line. FIG. The symbols of the constituent elements of the first element are given a symbol U, and the symbols of the constituent elements of the second element are given a symbol D. Constituent elements having the same reference numeral indicate the same constituent elements. The first element 10U will be described. The coordinate system has an x-axis in the signal propagation direction, a z-axis upward, and a y-axis in the width direction perpendicular to the signal propagation direction. A first conductor layer 13U is formed on the first surface 12U which is the upper surface of the first dielectric substrate 11U. When the upper and lower sides are expressed with respect to the substrate, the upper and lower definitions are common to the first dielectric substrate 11U and the second dielectric substrate 11D, and the + z axis direction is upward and the −z axis direction is downward. It is defined as As shown in FIG. 4, a second conductor layer 19U is formed on the entire surface of the second surface 18U, which is the lower surface of the first dielectric substrate 11U. As shown in FIG. 2, the first conductor layer 13U is connected to the input signal line 14U, the input signal line 14U from the signal input port Port 1 side, and the first signal line 16U extending in the x-axis direction, It consists of a first portion 15U of the first conductor layer 13U formed on both sides of the first signal line 16U and a conductor portion 21U of the first integrated waveguide 20U.

  In FIG. 2, the first dielectric substrate 11U is divided into regions A, B, C, and D shown in the x-axis direction. The region D is a region where the input signal line 14U is formed, the region C is a first coplanar portion, the region B is a first exposed portion, and the region A is a region where the first integrated waveguide 20U is formed.

  The first coplanar portion C is composed of the first signal line 16U and the first portions 15U of the first conductor layer 13U provided on both sides thereof. The first portion 15U is electrically connected to the second conductor layer 19U formed on the back surface of the first dielectric substrate 11U by a number of vias 17U. In the first exposed portion B, except for the first signal line 16U passing through the center, the first conductor layer 13U is missing with a width W in the direction perpendicular to the signal propagation direction, and the dielectric is exposed. It is the part which is doing. The first integrated waveguide 20U includes a conductor portion 21U that is a main portion of the first conductor layer 13U, a second conductor layer 19U on the lower surface of the first dielectric substrate 11U corresponding to the conductor portion 21U, and a conductor. It is comprised from many via | veer 22U which electrically connects the part 21 and the 2nd conductor layer 21U. A large number of vias 22U are arranged on two lines K1 and K2 having a distance W along the signal propagation direction and on a line K3 in the width direction perpendicular to the lines. The row of vias 22U arranged on the lines K1, K2 constitutes the first side wall 23U of the first integrated waveguide 20U, and the row of vias 22U arranged on the line K3 is the first integrated waveguide. A 20U first short-circuit wall 24U is formed. The interval between these vias 22U is shorter than the cutoff wavelength. These rows of conductive vias act as conductor walls for propagating electromagnetic waves. The first short-circuit wall 24U is a conductor wall formed at the destination of signal propagation, and the electric field is zero on this wall surface. Since the via functions as a conductor wall, the first short-circuit wall 24U and the first side wall 23U may be formed of a continuous plate-like conductor instead of the via.

As shown in FIG. 4, in the second conductive layer 19U, a distance in the -x-axis direction from the first short-circuit wall 24U is, to 1/4 of the position of the guide wavelength lambda _g corresponding to a reference frequency, a second A first slot 25U is formed in which the conductor layer 19U is cut into a rectangle parallel to the widthwise y-axis direction. The width L of the first slot 25U is configured to be smaller than the interval W between the pair of first side walls 23U of the first integrated waveguide 20U. Hereinafter, this interval W is referred to as the integrated waveguide width, and this width L is referred to as the long side width of the slot.

  Further, the second element 10D is configured as shown in FIG. The second element 10D is equivalent to the first element 10U that is turned upside down and rotated 180 degrees. In the first element 10U, a signal propagates from the input signal line 14U toward the first integrated waveguide 20U, whereas in the second element 10D, a signal is output from the second integrated waveguide 20D to the output signal line. Only the propagation towards 14D is different.

  A third conductor layer 13D is formed on the third surface 12D which is the lower surface of the second dielectric substrate 11D. Further, as shown in FIG. 4, a fourth conductor layer 19D is formed on the entire surface of the fourth surface 18D, which is the upper surface of the second dielectric substrate 11D. The third conductor layer 13D is connected to the output signal line 14D and the output signal line 14D from the signal output port Port 2 side, and extends in the −x-axis direction opposite to the signal propagation direction. 16D, a first portion 15D of the third conductor layer 13D formed on both sides of the second signal line 16D, and a conductor portion 21D of the second integrated waveguide 20D. Since these configurations are the same as those of the first element 10U, description thereof is omitted.

  A large number of vias 22D are arranged on two lines K1 and K2 having a distance W along the signal propagation direction and on a line K3 in the width direction perpendicular to the lines. The row of vias 22D arranged on the lines K1, K2 constitutes the second side wall 23D of the second integrated waveguide 20D, and the row of vias 22D arranged on the line K3 is the second integrated waveguide. The 20D 2nd short circuit wall 24D is comprised. The second short-circuit wall 24D is a conductor wall formed in the original direction in which the signal propagates, and the electric field is zero on this wall surface.

As shown in FIG. 4, in the fourth conductor layer 19D, the fourth conductive layer 19D has a distance in the x-axis direction from the second short-circuit wall 24D at a position that is ¼ of the guide wavelength λ _g corresponding to the reference frequency. A second slot 25U is formed in which the body layer 19U is cut into a rectangle parallel to the widthwise y-axis direction. The long side width L of the second slot 25U is configured to be smaller than the integrated waveguide width W of the second integrated waveguide 20U.

  As shown in FIG. 4, the first element 10U and the second element 10D are formed on the upper surface of the second dielectric substrate 11D and the second conductor layer 19U formed on the lower surface of the first dielectric substrate 11U. The fourth conductor layer 19 </ b> D is disposed on both surfaces 51 and 52 of the base 50 in the facing direction. The first slot 25U and the second slot 25D are parallel, and the long sides thereof have the same position in the x-axis direction, which is the signal propagation direction, in the first element 10U and the second element 10D. The base 50 is composed of a first base 53 made of copper, a second base 54 made of resin and having an exposed surface coated with a copper coating 57, and a third base 55 made of aluminum. It consists of a structure. A waveguide 56 made of a rectangular parallelepiped cavity is formed so as to connect the first slot 25U and the second slot 25D in the thickness direction of the base 50 constituted by these. The four side wall surfaces of the waveguide 56 are made of copper of the first base 53, copper coating 57 of the second base 54, and aluminum of the third base 55. The input end face 58 of the waveguide 56 completely encloses the first slot 25U, and the output end face 59 completely encloses the second slot 25D. Further, the width (long side width) in the y-axis direction of the input end face 58 and the output end face 59 is the same as the width of the second conductor layer 19U and the width of the fourth conductor layer 19D. The short side width 59 (the width in the x-axis direction) 59 is wider than the short side widths of the first slot 25U and the second slot 25D. Therefore, the input end face 58 is blocked by the second conductor layer 19U on the entire circumference of the first slot 25U, and the output end face 59 is blocked by the fourth conductor layer 19D on the entire circumference of the second slot 25D. , Blocked. The portion of the first base 53 of the waveguide 56 has protrusions 61 and 62 that protrude into the cavity and extend in the y-axis direction. The distance between the protrusions 61 and 62 is the first slot 25U and the second slot. A throttle portion 60 is provided which is narrowed to the short side width of the slot 25D. The long side width (the width in the y-axis direction) of the throttle unit 60 is the same as the long side width of the first slot 25U and the second slot 25D.

The action of the first exposed portion B is to convert the electromagnetic field excitation mode from the TEM mode to the TE ₁₀ mode, and the second exposed portion B is to convert the electromagnetic field excitation mode from the TE ₁₀ mode to the TEM mode. is there. In the input signal line 14U configured by a microstrip line, an electric field is generated from the input signal line 14U toward the second conductor layer 19U on the lower surface, and in the first coplanar part C, the first portion of the first conductor layer 13U is generated. 15U becomes the ground potential, and the conductor portion 21U of the first integrated waveguide 20U is also at the ground potential. Therefore, in the first slot portion C, the electric field propagates in parallel with the upper surface of the first dielectric substrate 11U. Excited in the direction. In the first integrated waveguide 20U, this TEM mode is converted into a TE ₁₀ mode in which an electric field is excited in the thickness direction (z-axis direction) of the first dielectric substrate 11U perpendicular to the signal propagation direction. . The relationship between the second integrated waveguide 20D and the second slot portion C is the same as this. In this way, mode conversion is performed smoothly.

The reflection characteristic at the input port Port 1 of the transmission line 100 is shown in FIG. Further, the transmission characteristic from the input port Port 1 to the output port Port 2 is shown in FIG. These characteristics are that the integrated waveguide width W of the first integrated waveguide 20U and the second integrated waveguide 20D is fixed to 1800 μm, and the short side width of the slot is fixed to 100 μm, and the first slot 25U and the second slot 25D. This is a characteristic simulated by electromagnetic field analysis by changing the long side width L (FIG. 2). The characteristics are expressed using the deviation of the long side width with respect to the reference length L ₀ = 1425 μm as a parameter. The design reference frequency is 77 GHz.

From the characteristics of FIG. 5A, it can be seen that the first resonance frequency in the vicinity of 78 GHz does not change even when the short side width L of the slot is changed. The first resonance frequency is determined by the distance between the first slot 25U and the first short-circuit wall 24U in the x-axis direction and the distance between the second slot 25D and the second short-circuit wall 24D in the x-axis direction. Both intervals are equal. That is, the frequency at which the interval length is equal to ¼ of the guide wavelength λ _G is the first resonance frequency. At the first resonance frequency, the standing wave of the electric field is zero at the positions of the first short-circuit wall 24U and the second short-circuit wall 24D, and the first resonance frequency is constant at the positions of the first slot 25U and the second slot 25D. It becomes an antinode of standing waves, and the maximum amplitude is obtained. As a result, the signal having the first resonance frequency is most easily propagated from the first slot 25U toward the second slot 25D.

  On the other hand, in the first slot 25U and the second slot 25D, an electric field is generated in a direction parallel to the surfaces of the first conductor layer 13U and the second conductor layer 13D. At both ends of the long side width (the width in the y-axis direction) of these slots, the electric field of the tangential component of the conductor becomes zero, and a standing wave having a half wavelength on the long side of the slot is induced. Therefore, in terms of dimensions, the resonance frequency in the slot is higher than the first resonance frequency. However, since there is no dielectric in the first slot 25U and the second slot 25D, the dielectric constant is smaller than the dielectric constants of the first integrated waveguide 20U and the second integrated waveguide 20D. For this reason, the resonance frequency is lowered. As a comprehensive result, it is understood that the second resonance frequency is lower than the first resonance frequency, and the second resonance frequency is increased as the long side width of the slot is reduced.

Next, the long side width L of the first slot 25U and the second slot 25D is fixed to 1700 μm and the short side width is fixed to 100 μm, and the integrated waveguide width W of the first integrated waveguide 20U is changed, that is, The characteristics of the transmission line 100 were simulated by changing the distance between the pair of first side walls 23U and the distance between the pair of second side walls 23D. A reflection characteristic at the input port Port 1 is shown in FIG. Also, the transmission characteristics from the input port Port 1 to the output port Port 2 are shown in FIG. These characteristics are simulated by electromagnetic field analysis using a deviation of the integrated waveguide width W from the reference value W ₀ = 1800 μm as a parameter. The design reference frequency is 77 GHz.

The distance in the propagation direction of the signal between the first slot 25U and the first short-circuit wall 24U and the distance in the propagation direction of the signal between the second slot 25D and the second short-circuit wall 24D are frequencies that are ¼ of the guide wavelength λ _G. Resonates. At this time, as the integrated waveguide width W becomes longer, the cutoff frequency becomes smaller. As a result, the guide wavelength becomes longer at the same frequency. As a result, the position of λ _G / 4 is further away from the first short-circuit wall 24U and the second short-circuit wall 24D with respect to the positions where the first slot 25U and the second slot 25D exist. Conversely, the frequency at which the positions of the first slot 25U and the second slot 25D are λ _G / 4 becomes lower as the integrated waveguide width W becomes longer. As a result, as shown in FIG. 6A, the first resonance frequency moves to a lower frequency side as the waveguide width W becomes longer, and as the integrated waveguide width W becomes shorter, It moves to the higher frequency side. On the other hand, the second resonance frequency is determined by the long side width L of the first slot 25U and the second slot 25D. In this simulation, since the long side width L of the slot is not changed, the second resonance frequency does not change even if the integrated waveguide width W is changed as shown in FIG. Also, from this result, it is understood that when the integrated waveguide width W is 1900 μm, a band where a reflection loss of 15 dB or more is secured can be a band of 4.6 GHz from 74.8 GHz to 78.2 GHz. The The band in which the reflection loss of 10 dB or more is obtained is 4.3 GHz from 74.2 GHz to 78.5 GHz. According to the characteristics of Patent Document 2, although the center frequency is 27 GHz and the center frequency is different, the bandwidth that causes the reflection loss of 15 dB or more is about 0.3 GHz, and the bandwidth that causes the reflection loss of 10 dB or more is 0.6 GHz. It is understood that the bandwidth of the transmission line of the present embodiment is expanded at each stage.

Next, the long side width L of the first slot 25U and the second slot 25D is fixed to 1700 μm, the short side width is set to 100 μm, and the integrated waveguide width W is fixed to 1900 μm. And the characteristics of the transmission line 100 were simulated. The reflection characteristics at the input port Port 1 are shown in FIG. Further, the transmission characteristic from the input port Port 1 to the output port Port 2 is shown in FIG. These characteristics are simulated by electromagnetic field analysis using a deviation of the short side width β of the diaphragm 60 from the reference value β ₀ = 100 μm as a parameter. The design reference frequency is 77 GHz.

As can be seen from FIG. 7A, it is understood that the narrower the short side width of the stop portion 60, the larger the reflection loss at the input port Port 1 and the better the characteristics.
In FIG. 2, the first dielectric substrate 11U is divided into regions A, B, C, and D shown in the x-axis direction. The region D is a region where the input signal line 14U is formed, the region C is a first coplanar portion, the region B is a first exposed portion, and the region A is a region where the first integrated waveguide 20U is formed.

  It is also possible to configure as shown in FIG. FIG. 8 shows the configuration of the first element 10U, but the configuration of the second element 10D is the same. Parts having the same functions as those in the first embodiment are denoted by the same reference numerals. In the present embodiment, the first coplanar portion C and the first exposed portion B in the first embodiment are excluded. That is, the input signal line 14U is directly connected to the conductor portion 21U that is the main portion of the first conductor layer 13U of the first integrated waveguide 20U. Even with such a configuration, a signal can be propagated from the input signal line 14U of the microstrip to the first integrated waveguide 20U. Similarly, the second element 10D is directly connected to the conductor portion 21D that is the main portion of the third conductor layer 13D of the second integrated waveguide 20D and to the output signal line 14D that is a microstrip. Even with such a configuration, a signal can be propagated from the second integrated waveguide 20D to the output signal line 14D.

  Further, the impedance of the first integrated waveguide 20U and the second integrated waveguide 20D can be changed by the integrated waveguide width W. Accordingly, the integrated waveguide width W is determined so that impedance matching is achieved between the first integrated waveguide 20U and the second integrated waveguide 20D. Alternatively, the first integrated waveguide 20U and the second integrated waveguide 20D may be cascade-connected with two or more integrated waveguides having different widths W. Thereby, adjustment of impedance becomes easy.

  The present invention can be used for a signal transmission circuit for an antenna such as a radar device or a reception circuit for a signal from an antenna. By using the present invention, the use frequency bandwidth of the radar apparatus can be widened, and UWB communication can be used.

The perspective view which shows the structure of the transmission line which concerns on one specific Example of this invention. The top view of the 1st element | device of the transmission line which concerns on the Example. The top view of the 2nd element of the transmission line which concerns on the same Example. Sectional drawing of the transmission line which concerns on the Example. In the transmission line according to the example, the reflection characteristics when the slot width is changed. In the transmission line according to the example, the transmission characteristics when the slot width is changed. In the transmission line according to the example, the reflection characteristics when the width of the integrated waveguide is changed. In the transmission line according to the example, the transmission characteristics when the width of the integrated waveguide is changed. In the transmission line according to the example, the reflection characteristics when the short side width of the narrowed portion of the waveguide is changed. In the transmission line according to the example, transmission characteristics when the short side width of the narrowed portion of the waveguide is changed. The top view of the 1st element | device of the transmission line which concerns on the other Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Transmission line 10U, 10D ... 1st element, 2nd element 11U, 11D ... 1st dielectric substrate, 2nd dielectric substrate 13U, 13D ... 1st conductor layer, 3rd conductor layer 14U, 14D ... 1st 1 signal line, 2nd signal line 19U, 19D ... 2nd conductor layer, 4th conductor layer 22U, 22D ... 1st side wall, 2nd side wall 25U, 25D ... 1st slot, 2nd slot 20U, 20D ... 1st 1 integrated waveguide, 2nd integrated waveguide 24U, 24D ... 1st short circuit wall, 2nd short circuit wall 56 ... Waveguide 50 ... Base

Claims (4)

In transmission lines using integrated waveguides,
A first dielectric substrate having a first surface that is an upper surface and a second surface that is a lower surface;
A first conductor layer formed on the first surface;
A second conductor layer formed on the second surface;
On the first conductor layer, except for a portion connected to the input signal line, provided along each side of the rectangular shape, penetrating the first dielectric substrate and the first conductor layer and the A first short-circuit wall formed on a side opposite to a side to which the input signal line is connected and electrically connected to the second conductor layer, and two parallel first side walls perpendicular thereto A first conducting member;
The second conductor layer is provided on the input signal line side at a position 1/4 of the guide wavelength from the first short-circuit wall, and is narrower than the distance between the two first side walls and perpendicular to the signal propagation direction. A first slot in which the conductor layer is cut out by a width,
A second dielectric substrate having a third surface that is a lower surface and a fourth surface that is an upper surface and a surface closer to the second surface, and is provided in parallel with the first dielectric substrate;
A third conductor layer formed on the third surface;
A fourth conductor layer formed on the fourth surface;
On the third conductor layer, except for the portion connected to the output signal line, provided along each side of the rectangular shape, penetrating through the second dielectric substrate, the third conductor layer and the A second short-circuit wall formed on a side opposite to the side to which the output signal line is connected and electrically connected to the fourth conductor layer, and two parallel second side walls orthogonal to the second short-circuit wall A second conducting member;
The fourth conductor layer is provided on the output signal line side at a position 1/4 of the guide wavelength from the second short-circuit wall, and is narrower than the interval between the two second side walls and perpendicular to the signal propagation direction. A second slot in which the conductor layer is cut out by a certain width,
The first dielectric substrate and the second dielectric substrate are disposed so that the first slot and the second slot are parallel to each other, and the first slot and the second slot are disposed therein. And a base on which a waveguide connecting the two is formed.   The transmission line according to claim 1, wherein the waveguide has a narrowed portion in which a distance between short sides of the waveguide is narrow. The first conductor layer is
A first signal line connected to the input signal line formed on the first surface, and a first conductor layer formed on both sides of the first signal line and electrically connected to the second conductor layer A first coplanar portion comprising a first portion of
Connected to the first coplanar portion, the first signal line passes through the central portion, the first conductor layer is missing in the width direction perpendicular to the signal transmission direction, and the surface of the first dielectric substrate is exposed. The first exposed portion,
The transmission line according to claim 1, further comprising: The third conductor layer is
A second signal line connected to the output signal line formed on the third surface, and a third conductor layer formed on both sides of the second signal line and electrically connected to the fourth conductor layer A second coplanar portion comprising a first portion of
Connected to the second coplanar part, the second signal line passes through the central part, the third conductor layer is missing in the width direction perpendicular to the signal transmission direction, and the surface of the second dielectric substrate is exposed. The second exposed portion,
The transmission line according to any one of claims 1 to 3, wherein the transmission line is provided.

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