Waveguide device and radar device

Abstract

To provide a waveguide device capable of connecting a millimeter wave IC transmission / reception terminal with an antenna radiation element efficiently each other.SOLUTION: In a waveguide device 1, a high frequency circuit 10 having a transmission / reception terminal 11 and a signal ground (SG) terminal 12 is disposed on an upper surface side of a substrate 100, a first member 102 having a conductive lower surface electrically connected to the SG terminal is disposed on a lower surface side of the substrate, a second member 200 having a conductive upper surface is disposed on the lower surface side of the first member, a ridge 201 having a strip-shaped conductive upper surface is disposed on the upper surface side of the second member, and a second waveguide 5 is formed between the conductive upper surface of the ridge and the lower surface of the first member. A first waveguide 3 includes a core conductor 300 and a peripheral conductor 103 penetrating the substrate 100 in a vertical direction. An upper feeding part 302 is disposed on the substrate, and connects the transmission / reception terminal and the upper end of the core conductor at an electromagnetic wave level. A lower end of a lower feeding conductor 303, the upper end of which is in contact with the lower end of the core conductor, is in contact with or high-frequency-coupled to the conductive upper surface of the ridge.SELECTED DRAWING: Figure 33

Description

[Technical Field]

[0001] The present invention relates to a waveguide device and a radar device. [Background technology]

[0002] In recent years, research and development into millimeter-wave sensing and communications has expanded, creating a demand for high-gain, low-loss, wideband, and multi-channel antennas. In response to this demand, progress has been made in the development of WRG (Waffle Iron Ridge waveGuide) technology, which is useful as a next-generation antenna and waveguide (see Patent Documents 1 and 2). Figure 3 of Patent Document 1 discloses the world's first basic structure of a WRG. Patent Document 2 discloses a subordinate ancillary structure, in which two conductive members constituting this basic structure are fixed outside the waveguide region, as one of the structures of a WRG for high-frequency bands such as millimeter waves.

[0003] One of the features of WRG technology is that in the multiple waveguides within the antenna, located from the millimeter-wave IC (MMIC: Monolithic Microwave Integrated Circuit) to the antenna radiating element that transmits and receives millimeter-wave electromagnetic waves, separation walls are formed to prevent mutual coupling between adjacent waveguides. This prevents leakage of propagating electromagnetic waves, maintaining transmission loss at the same level as metal waveguides and minimizing interference with electromagnetic waves transmitted through other adjacent waveguides. Conventional microstrip waveguides and microstrip antennas do not have such separation walls.

[0004] A major application of millimeter-wave antennas is imaging radar sensing, which has multiple transmit and receive channels. When using microstrip antennas for this purpose, in addition to the large loss in the waveguide, interference due to mutual coupling between adjacent waveguides and antenna radiating elements can cause problems with target detection accuracy. On the other hand, using WRG technology for such multi-channel antennas not only significantly reduces waveguide loss but also significantly reduces mutual coupling between waveguides within the antenna. Furthermore, using antenna radiating elements suitable for WRG, such as mini-horn antennas and slot antennas, can further reduce mutual coupling. This ensures accurate signal transmission and reception between the antenna radiating elements and the transmit and receive terminals of the millimeter-wave integrated circuit (IC) that transmits and receives these signals. As a result, in millimeter-wave radar sensing, for example, the target signal contained in the received electromagnetic waves from the target can be accurately detected, enabling accurate target detection.

[0005] With WRG technology, this separation wall is realized by magnetic walls provided on both sides of the ridge waveguide, specifically with a periodic structure such as a rod array. If this magnetic wall is realized with a single rod array, the separation effect can be expected to be about 30 dB. To further enhance this separation effect, if two rod arrays are provided between the two ridge waveguides, the separation effect can be expected to be about 40 dB, achieving high separation performance suitable for an array antenna.

[0006] Such magnetic walls have the function of confining electromagnetic waves in the corresponding frequency band. The structures that make up these walls are called artificial magnetic conductors (AMCs), and can be realized with structures other than rod arrays (see, for example, Patent Document 2). Specifically, the description in the middle of paragraph

[0015] of Patent Document 2 is helpful: "The texture or structure is often periodic or quasi-periodic and is designed to interact with waves so as to behave macroscopically as an artificial magnetic conductor (AMC), electromagnetic band gap (EBG) surface, or soft surface."

[0007] Future imaging radars using WRGs will increasingly have more transmit and receive channels for more accurate target detection. To increase the number of channels, millimeter-wave ICs with a corresponding number of transmit and receive terminals are used. A waveguide within the antenna, for example, is sometimes provided, connecting these transmit and receive terminals to the transmit and receive apertures (antenna radiating elements) in a one-to-one relationship. The millimeter-wave IC is typically mounted on a high-frequency circuit board and connected to the ridge waveguide of the WRG via a waveguide (usually a microstrip line) on the board. Conventionally, this connection has been achieved by mounting a transducer or other device on the board, connecting it to a rectangular waveguide, and then connecting this rectangular waveguide to the ridge waveguide of the WRG (see Patent Documents 3 and 4). In addition, in experiments using waveguide devices, a structure has been proposed in which the electromagnetic waves of the experimental subject are guided through a coaxial cable and connected to a ridge-shaped coaxial connector (see Non-Patent Document 1). [Prior art documents] [Patent documents]

[0008] [Patent Document 1] WO2003-065497(EP1331688) [Patent Document 2] Special Publication No. 2011-527171 [Patent Document 3] Japanese Patent Application Laid-Open No. 2011-120155 [Patent Document 4] Japanese Patent Application Publication No. 2018-207487 [Non-patent literature]

[0009] [Non-Patent Document 1] Per-Simon Kildal, Ashraf Uz Zaman, Eva Rajo-Iglesias, Esperanza Alfonso, Alejandro Valero-Nogueira, "Design and Experimental Verification of Ridge Gap Waveguide in Bed of Nails for Parallel Plate Mode Suppression", IET Microwaves, Antennas and Propagation, January 2009 Summary of the Invention [Problem to be solved by the invention]

[0010] The prior art of Patent Document 3 requires the provision of transducers and rectangular waveguides for each waveguide corresponding to each antenna radiating element. Increasing the number of transmit / receive channels increases the installation space required for these, resulting in a larger waveguide device. The prior art of Patent Document 4 makes it difficult to achieve stable connections between the transmit / receive terminals of a millimeter-wave IC mounted on a substrate and the end of a waveguide mounted within the substrate, especially during mass production. Increasing the number of transmit / receive channels also increases the installation space required for waveguides and the like, resulting in an increase in the substrate area around the millimeter-wave IC. Furthermore, the prior art of Non-Patent Document 1 requires coaxial connectors to be placed on the ridge waveguides to be connected. When this technique is applied to a waveguide device with a large number of transmit / receive channels, coaxial connectors must be placed on all corresponding ridge waveguides, and further coaxial connectors must be placed on the waveguides on the transmit / receive terminal side of the millimeter-wave IC that receives these, resulting in a larger device. The present invention has been made in consideration of the above-mentioned problems, and aims to provide a waveguide device and a radar device that can connect a millimeter-wave IC transmitting / receiving terminal and an antenna radiating element simply, space-savingly, inexpensively, and efficiently, even in a waveguide device with a large number of channels. [Means for solving the problem]

[0011] The present invention relates to a first waveguide including a substrate having an upper surface and a lower surface, a high-frequency circuit arranged on the upper surface side of the substrate and having a terminal for transmitting or receiving and a signal ground terminal, a first member arranged on the lower surface or on the lower surface side of the substrate along the substrate and having a conductive lower surface that is electrically connected to the signal ground terminal of the high-frequency circuit, a core conductor that passes through the substrate and the first member in the vertical direction, and a peripheral conductor that is arranged around the core conductor along the core conductor with an insulator interposed therebetween and in contact with the conductive lower surface of the first member, a second member arranged along the lower surface side of the first member and having a conductive upper surface, and a second member between the first member and the second member. a ridge disposed between the first member and the second member and having a waveguide surface which is a strip-shaped conductive upper surface facing the conductive lower surface of the first member; a second waveguide constituted by the waveguide surface of the ridge and the conductive lower surface of the first member; an electromagnetic wave blocking wall disposed between the first member and the second member and disposed adjacent to the second waveguide; an upper feed section disposed on the upper surface of the substrate and electromagnetically connecting the transmitting or receiving terminal of the high-frequency circuit to an end of the core conductor on the upper surface side of the substrate; and a lower feed conductor which brings into contact with or high-frequency couples a lower end of the core conductor on the lower surface side of the first member with an upper surface of the ridge disposed below the lower end. In the above configuration, the core conductor and the lower power-feed conductor may be formed from a core extension conductor that is continuously formed from the same material. In the above configuration, the upper feeding portion may be a waveguide formed by a microstrip line, a coplanar line, or a post wall. In the above configuration, a plurality of through via holes may be provided around the microstrip line or the coplanar line so as to surround the microstrip line or the coplanar line. In the above configuration, the upper end of the core conductor may be formed on the upper surface of a substrate outside an MMIC package that constitutes the high-frequency circuit. In the above configuration, the upper power supply portion may be configured to bring the terminal for transmitting or receiving of the high-frequency circuit into contact with the end of the core conductor on the upper surface side of the board, and to bring the peripheral conductor into contact with a ground used for transmitting or receiving of the high-frequency circuit. In the above configuration, the terminal for transmitting or receiving and the end of the core conductor on the upper surface side of the board may be arranged to overlap in a vertical stereoscopic view. In the above configuration, a pin-shaped conductor may be arranged so that one end of the pin-shaped conductor is in contact with the terminal for transmission or reception, and the pin-shaped conductor may constitute the core conductor and the lower feed conductor. In the above configuration, the terminal for transmitting or receiving may contact one end of a socket pin of an IC socket arranged on the substrate, and the socket pin may constitute the core conductor and the lower feed conductor. In the above configuration, the lower end of the lower feed conductor may be disposed on the upper surface of the ridge or in a recess or through-hole formed in the upper surface of the ridge, and may be in contact with or high-frequency coupled to the ridge. In the above configuration, the lower end of the lower power supply conductor may be positioned opposite one end face of the ridge in the direction in which the ridge extends, or may be positioned within a through slit formed in the ridge, and may be in contact with or high-frequency coupled to the ridge. In the above configuration, the inner diameter of the recess or the through hole may be equal to or less than half the wavelength of the electromagnetic wave propagating through the second waveguide.

[0012] In the above configuration, the ridge may have an uneven portion provided on the upper surface thereof close to the lower end of the lower power supply conductor, a thickness-changing portion provided on the left and right side surfaces in the direction in which the ridge extends, or a convex portion provided on the end surface of the ridge or the end surface of the through slit in the direction in which the ridge extends. In the above configuration, the core conductor may have a board-side recess at its lower end, and the lower power supply conductor may have a tapered side at its upper end that narrows from bottom to top, and the upper end may be inserted into the board-side recess and come into contact with the core conductor. In the above configuration, the substrate may have a substrate through-hole around the side surface of the portion corresponding to the core conductor, and the core extension conductor may have a tapered side surface at its upper end that narrows from bottom to top, and the upper end may contact the upper power supply portion. In the above configuration, the ridge may have a ridge-side recess formed on the upper surface thereof, and the lower power supply conductor may have a tapered side at its lower end that narrows from top to bottom, and the lower end may be inserted into the ridge-side recess, so that the lower power supply conductor and the ridge come into contact with each other. In the above configuration, the ridge and the second member may have a ridge through-hole that penetrates the ridge and the second member in the vertical direction, and a lower portion of the lower power supply conductor may be inserted into the ridge through-hole to come into contact with or be high-frequency coupled to the ridge.

[0013] In the above configuration, the ridge and the second member may have a ridge through-hole that penetrates the ridge and the second member in the vertical direction, and the lower portion of the lower power supply conductor may be inserted into the ridge through-hole and contact the second member that constitutes the ridge via solder. In the above configuration, a conductive elastic body may be arranged on the upper end of the lower power supply conductor, and the lower end of the lower power supply conductor may be urged toward the upper surface of the ridge by the conductive elastic body and contact the upper surface.

[0014] In the above configuration, a first rod-shaped conductor may be arranged on the second member at a position beyond the end of the ridge on the upper surface of the ridge in the direction of extension, the first rod-shaped conductor having one end adjacent to the portion of the upper surface of the ridge that is in contact with or high-frequency coupled to the lower end of the lower power supply conductor, and a second rod-shaped conductor may be arranged on the second member at a position beyond the other end of the ridge in the direction of extension. In the above configuration, an upper end of the first rod-shaped conductor or the second rod-shaped conductor may be in contact with or high-frequency coupled to a lower surface of the first member.

[0015] In the above configuration, the first rod-shaped conductor or the second rod-shaped conductor may be composed of a wall portion whose width in a direction along the extension direction of the ridge and in a direction perpendicular to the height direction has a length of at least 1 / 4 of the free space wavelength λo of the electromagnetic wave at the center frequency of the operating frequency band. In the above configuration, the core conductor and the peripheral conductor may each be made of a single conductor, and the single peripheral conductor may be disposed adjacent to the single core conductor. In the above configuration, the core conductor may be made of one conductor, the peripheral conductor may be made of two conductors, and the one core conductor may be disposed between the two peripheral conductors.

[0016] In the above configuration, the core conductor may consist of one conductor, the peripheral conductor may consist of multiple linear conductors, and the multiple peripheral conductors may be arranged along a portion of the outer periphery of the single core conductor, or approximately half of the multiple peripheral conductors may be arranged along a portion of the outer periphery of the single core conductor, and the remaining half of the multiple peripheral conductors may be arranged along the periphery of another portion opposite to the portion of the outer periphery. In the above configuration, the core conductor may consist of one conductor, the peripheral conductor may consist of multiple linear conductors or multiple plate-shaped conductors, and the multiple peripheral conductors may be arranged along almost the entire circumference of the single core conductor. In the above configuration, the core conductor may be made of one conductor, and the peripheral conductor may be made of one cylindrical conductor, and the peripheral conductor may be disposed so as to surround the outer periphery of the one core conductor. In the above configuration, the first member can be formed of a ground pattern formed on the lower surface of the substrate.

[0017] In the above configuration, the electromagnetic wave blocking wall can be composed of rods having conductive top and side surfaces formed on at least one of the bottom surface of the first member or the top surface of the second member, and the multiple rods can be configured to block the propagation of electromagnetic waves in directions other than the propagation direction defined by the ridge, at least at the operating frequency.

[0018] In the above configuration, the electromagnetic wave blocking wall can be composed of conductive posts that join the lower surface of the first member and the upper surface of the second member, and the multiple posts can be configured to block the propagation of electromagnetic waves in directions other than the propagation direction defined by the ridge, at least at the operating frequency.

[0019] In the above configuration, the electromagnetic wave blocking wall has an EBG (Electromagnetic Band Gap) structure formed on at least one of the lower surface of the first member or the upper surface of the second member, and the EBG structure can be configured to block the propagation of electromagnetic waves in directions other than the propagation direction defined by the ridge, at least at the operating frequency.

[0020] In the above configuration, the high-frequency circuit may have a plurality of the transmitting or receiving terminals, a plurality of the first waveguides each corresponding one-to-one to the plurality of transmitting or receiving terminals, a plurality of the second waveguides each corresponding one-to-one to the plurality of first waveguides, and a plurality of the lower feed conductors each corresponding one-to-one to the plurality of second waveguides, and the plurality of lower feed conductors may be bundled by an insulating restraining member so that their lower ends can be inserted into the corresponding recesses or through holes formed in the upper surface of the ridge.

[0021] The present invention provides a radar device having a waveguide device of the above configuration, a waveguide that vertically penetrates the second member adjacent to the end of the ridge in the extension direction, a rod-shaped conductor or wall portion that faces the end of the ridge in the extension direction of the ridge, and an antenna radiating element that radiates electromagnetic waves propagated through the waveguide.

[0022] The present invention provides a radar device comprising: a waveguide device having the above-described configuration; an antenna radiating element; one or more waveguides that propagate electromagnetic waves between the second waveguide and the antenna radiating element; and a radar calculation unit that calculates position and relative velocity information of a detection target based on the electromagnetic waves transmitted and received by the antenna radiating element. [Effects of the Invention]

[0023] According to the present invention, even in a waveguide device with a large number of channels, it is possible to connect a millimeter-wave IC transmitting / receiving terminal and an antenna radiating element simply, space-savingly, inexpensively and efficiently. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a perspective view showing a schematic configuration example of a waveguide device 1 according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line AA' in FIG. [Figure 3] 1A is a top view of the WRG structure 4, FIG. 1B is a partial perspective view of the WRG structure 4, and FIG. 1C is a partial cross-sectional view taken along line BB' in FIG. [Figure 4A] 1 is a diagram showing a first example of a connection configuration of components in IC mounting board 2, and is a partial top view of IC mounting board 2 as seen from the upper surface side. FIG. [Figure 4B] 1 is a diagram showing a first example of a connection configuration of components in IC mounting board 2, and is a partial bottom view of IC mounting board 2 as seen from the bottom side. FIG. [Figure 4C] FIG. 1A is a diagram showing the structure of a microstrip line, FIG. 1B is a diagram showing the structure of a coplanar line, and FIG. 1C is a diagram showing the structure of a post-wall waveguide. [Figure 5A] 10 is a diagram showing a second example of a connection configuration of components in IC mounting board 2, and is a partial top view of IC mounting board 2 as seen from the upper surface side. FIG. [Figure 5B] 10 is a diagram showing a second example of a connection configuration of components in IC mounting board 2, and is a partial bottom view of IC mounting board 2 as seen from the bottom side. FIG. [Figure 6] FIG. 10 is a perspective view showing a schematic configuration example of a waveguide device 1A according to a second embodiment. [Figure 7] FIG. 7 is a partial cross-sectional view taken along line AA' in FIG. [Figure 8A] 1 is a partial cross-sectional view showing a first example of a direct connection configuration between a transmitting / receiving terminal 11 and a core conductor 300. FIG. [Figure 8B] 10 is a partial cross-sectional view showing a second example of a direct connection configuration between the transmitting and receiving terminal 11 and the core conductor 300. FIG. [Figure 9] FIG. 10 is a schematic diagram showing an example of the arrangement of the tip of the ridge 201 in a direct connection configuration. [Figure 10A] 10(a) to 10(h) are top views showing structural examples of the first waveguide 3 according to Modification 1. FIG. [Figure 10B] FIG. 10B is a partial cross-sectional view showing a specific example of the configuration of FIG. 10A(h). [Figure 11A] 10 is a partial cross-sectional view showing a first configuration example of a ridge contact type connection configuration (hereinafter referred to as a "ridge contact configuration") according to Modification 2. FIG. [Figure 11B] FIG. 10 is a partial cross-sectional view showing a second configuration example of a ridge contact configuration according to Modification 2. [Figure 12]FIG. 10 is a partial perspective view showing a state in which a plurality of lower power supply conductors are bundled together in the second configuration example. [Figure 13] FIG. 10 is a diagram showing a third configuration example of the ridge contact configuration according to the second modification. [Figure 14A] FIG. 10 is a partial cross-sectional view showing a first configuration example of a ridge contact configuration according to Modification 3. [Figure 14B] FIG. 10 is a diagram showing a second configuration example of a ridge contact configuration according to Modification 3. [Figure 15A] 10 is a partial cross-sectional view of a waveguide device 1 to which a first configuration example of a ridge contact configuration according to Modification 3 is applied. FIG. [Figure 15B] 10 is a partial cross-sectional view of a waveguide device 1 to which a second configuration example of a ridge contact configuration according to Modification 3 is applied. FIG. [Figure 15C] 10 is a partial cross-sectional view of a waveguide device 1 to which a third configuration example of a ridge contact configuration according to Modification 3 is applied. FIG. [Figure 15D] 10 is a partial cross-sectional view of a waveguide device 1 to which a fourth configuration example of a ridge contact configuration according to Modification 3 is applied. FIG. [Figure 16A] 10 is a partial cross-sectional view of a waveguide device 1 to which a fifth configuration example of a ridge contact configuration according to Modification 3 is applied. FIG. [Figure 16B] 10 is a partial cross-sectional view of a waveguide device 1 to which a sixth configuration example of a ridge contact configuration according to Modification 3 is applied. FIG. [Figure 17] (a) is a diagram showing the configuration of a core conductor 309 according to variant example 4, and (b) is a cross-sectional oblique view showing the state in which the core conductor 309 of (a) is arranged in the through hole of the substrate 100 and the through hole 204 of the WRG structure portion 4A. [Figure 18] 17(a) to (d) are diagrams showing the electromagnetic field distribution in the arrangement configuration of FIG. 17(b), where (a) and (c) are perspective views, (b) is a side view, and (d) is a front view. [Figure 19A] 13 is a partial bottom view showing the positional relationship between the ridge 201 and each terminal of the MMIC 10 in a direct-coupled configuration according to Modification 5. FIG. [Figure 19B] FIG. 10 is a partial cross-sectional view showing a configuration example in which the lower end of a core conductor 300 according to Modification 5 is fixed by soldering. [Figure 19C] FIG. 19C is a partial cross-sectional view for explaining an example of a soldering method applicable to the soldering in FIG. 19B. [Figure 20] FIG. 10(a) is a partial perspective view showing a first configuration example of high-frequency coupling according to Modification 6, and FIG. 10(b) is a partial cross-sectional view taken along line AA' in FIG. [Figure 21] (a) is a side view showing an example of the configuration of a core conductor 310 used for high-frequency coupling, (b) is a diagram showing an example of the configuration of a first waveguide 3, and (c) is a partially cross-sectional oblique view showing an example of the connection configuration of the core conductor 310 to the substrate 100. [Figure 22] FIG. 21 is a cross-sectional view taken along line AA' in FIG. 20(a). [Figure 23] 10(a) to 10(d) are diagrams showing the electromagnetic field distribution in a first configuration example of high-frequency coupling, where 10(a) and 10(c) are perspective views, 10(b) is a side view, and 10(d) is a front view. [Figure 24] FIG. 20 is a partial cross-sectional view showing a second configuration example of high-frequency coupling according to Modification 6. [Figure 25] 25 is a diagram showing the results of a simulation of the transmission characteristics and reflection characteristics of the first waveguide 3 having the configuration shown in FIG. 24. FIG. [Figure 26A] FIG. 20 is a partial perspective view showing a third configuration example of high-frequency coupling according to Modification 6. [Figure 26B] 26A, and (b) is a partially enlarged view of (a). [Figure 26C] 26B is a diagram showing the results of a simulation of the transmission characteristics and reflection characteristics of the first waveguide 3 having the configuration shown in FIG. 26A. FIG. [Figure 27A] FIG. 20 is a partial perspective view showing a fourth configuration example of high-frequency coupling according to Modification 6. [Figure 27B] FIG. 20 is a partial perspective view showing a fifth configuration example of high-frequency coupling according to the sixth modification. [Figure 28A] FIG. 13 is a cross-sectional view showing a schematic configuration example of a waveguide device 1B according to a seventh modification. [Figure 28B] FIG. 13 is a cross-sectional view showing a schematic configuration example of a waveguide device 1C according to an eighth modification. [Figure 28C]FIG. 13 is a top view of a WRG structure 4E according to a ninth modification. [Figure 28D] FIG. 28B is a cross-sectional view of a waveguide device 1D according to a ninth modification taken along line AA' in FIG. 28C. [Figure 29A] 13 is a cross-sectional view showing a schematic configuration example of a waveguide device 1E according to a first configuration example of a ninth modified example. FIG. [Figure 29B] 13 is a cross-sectional view showing a schematic configuration example of a waveguide device 1F according to a second configuration example of the ninth modification. FIG. [Figure 29C] FIG. 20 is a cross-sectional view showing a schematic configuration example of a waveguide device 1G according to a tenth modification. [Figure 29D] 10A and 10B are diagrams showing simulation results of the transmission characteristics and reflection characteristics of the first waveguide 3 and the second waveguide 5 of the waveguide device 1E. [Figure 29E] 10A and 10B are diagrams showing simulation results of the transmission characteristics and reflection characteristics of the first waveguide 3 and the second waveguide 5 of the waveguide device 1G. [Figure 30] 10(a) to 10(e) are schematic diagrams showing other structural examples of impedance matching between the first waveguide and the second waveguide by changing the thickness of the ridge, etc. FIG. [Figure 31A] (a) to (c) are partial cross-sectional views showing first to third structural examples of the electromagnetic wave shielding wall 210, and (d) to (f) are partial top views of the waveguide device having the structures of (a) to (c) as seen from the position cut along line CC'. [Figure 31B] (a) is a partial cross-sectional view showing fourth and fifth structural examples of the electromagnetic wave shielding wall 210, and (b) is a partial top view of the waveguide device having the structure of (a) as seen from the position cut along line CC'. [Figure 32] FIG. 1 is a cross-sectional view showing an example of a schematic configuration of a radar device 600. [Figure 33] 1 is a diagram schematically illustrating a basic structure of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments described below are merely examples of means for realizing the present invention, and may be modified or changed as appropriate depending on the configuration of the device to which the present invention is applied and various conditions. The present invention is not limited to the following embodiments. In the following drawings, identical or similar parts are denoted by identical or similar reference numerals. It should be noted, however, that the drawings are schematic and conceptual, and the vertical and horizontal dimensions and scales of components or parts differ from those of the actual parts. Therefore, specific dimensions and scales should be determined with reference to the following explanation. Of course, the drawings also include parts with different dimensional relationships and ratios. 〔term〕

[0026] "Millimeter waves" refer to electromagnetic waves with frequencies in the range of 30 GHz to 300 GHz. The wavelength of "millimeter waves" in a vacuum is in the range of 1 mm to 10 mm. Electromagnetic waves with wavelengths in the range of 10 mm to 30 mm are sometimes called "quasi-millimeter waves." The frequency band handled by the waveguide device of the present disclosure may be a band with a lower frequency than millimeter waves, or may be a band with a higher frequency than millimeter waves. The waveguide device may be used, for example, to propagate electromagnetic waves in the terahertz wave band (approximately 300 GHz or higher and 3 THz or lower).

[0027] A "high frequency circuit" is a semiconductor integrated circuit chip or package that generates or processes high frequency waves in the millimeter wave band. A "package" is a package that includes one or more semiconductor integrated circuit chips that generate or process high frequency waves in the millimeter wave band. A millimeter wave IC in which one or more millimeter wave ICs are integrated on a single semiconductor substrate is particularly called an MMIC (Monolithic Microwave Integrated Circuit). In this disclosure, examples using an "MMIC" as the "millimeter wave IC" will be mainly described. Furthermore, a "high frequency circuit" also includes, for example, a circuit composed of Schottky diodes used in a chemical reaction path and a high-power magnetron used for power transmission.

[0028] The package corresponds to a surface-mount type package. Examples include those with an L-shaped terminal configuration, such as SOP (Small Outline Package) and QFP (Quad Flat Package), and those with a J-shaped terminal configuration, such as SOJ (Small Outline J-leaded package) and QFJ (Quad Flat J-leaded package). In addition, it includes those with electrode pad terminal configurations, such as QFN (Quad Flat Non-leaded package) and LGA (Land Grid Array), and those with needle-shaped terminal configurations, such as PGA (Pin Grid Array). It also includes those with solder ball terminal configurations, such as BGA (Ball Grid Array) and EBGA (Enhanced BGA). An "IC mounting board" refers to a mounting board on which a millimeter-wave IC is mounted, and includes a "millimeter-wave IC" and a "substrate" as components. A simple "substrate" refers to a mounting board without a millimeter-wave IC mounted on it. [First embodiment] 〔composition〕

[0029] First, a first embodiment of the present invention will be described. FIGS. 1 to 5B are diagrams illustrating the first embodiment. FIG. 1 is a perspective view illustrating a schematic configuration example of a waveguide device 1 according to the first embodiment. FIG. 2 is a cross-sectional view taken along line A-A' in FIG. 1. In FIG. 2, wiring and other components formed on a substrate are partially shown floating in the air to clearly show the connection configuration. The waveguide device of the present invention can be used not only for transmitting and receiving high-frequency signals, but also for applications that do not use radio waves as signals, such as chemical reaction channels and power transmission. As shown in FIGS. 1 and 2, the waveguide device 1 includes an IC mounting substrate 2, multiple first waveguides 3, a WRG (Waffle Iron Ridge Wave Guide) structure 4, and multiple second waveguides 5, the number of which corresponds to the number of the first waveguides 3. The IC mounting substrate 2 includes a substrate 100 having an upper surface and a lower surface, a millimeter-wave IC 10 (hereinafter referred to as "MMIC 10") disposed (mounted) on the upper surface of the substrate 100, and a first member 102 disposed on the lower surface of the substrate 100.

[0030] Here, the term "top surface" refers to the collection of surfaces (including a single surface) that includes all surfaces included in the field of view when viewing an object such as substrate 100 from a far point above the Z axis, with the +Z direction of the Z axis in Figures 1 and 2 defined as up and the -Z direction as down. Similarly, the term "bottom surface" refers to the collection of surfaces that includes all surfaces included in the field of view when viewing an object from below the Z axis. In other words, even for objects with complex shapes with multiple surfaces, such as stepped shapes, the collection of these multiple surfaces is the top or bottom surface. Furthermore, whether or not the bottoms of recesses or holes present on the surface of each surface are included in the top and bottom surfaces is defined on a case-by-case basis. Furthermore, even if the object is flipped 180 degrees and the top surface defined in Figures 1 and 2 faces downward (in the -Z direction), it is still considered the top surface. Similarly, even if the bottom surface faces upward (in the +Z direction), it is still considered the bottom surface. The same applies to objects facing in other directions. Furthermore, "top side" refers to the upward direction, including the top surface. Similarly, "bottom side" refers to the downward direction, including the bottom surface.

[0031] 1 and 2, the +X direction is the forward direction, the −X direction is the rearward direction, the +Y direction is the leftward direction, and the −Y direction is the rightward direction. This also applies to subsequent figures from the same perspective. The IC mounting board 2 further includes a ground pattern 101 provided on the upper surface of the substrate 100. Here, the substrate 100 may be formed of, for example, a dielectric substrate. The substrate 100 is not limited to a flat plate, but may have a complex shape such as a 3D shape. In this case, a wiring pattern or the like can be formed using, for example, MID (Molded Interconnect Device) technology. The first member 102 can be formed of a ground pattern provided on the lower surface of the substrate 100, a thin conductive plate (e.g., a metal plate) separate from the substrate 100, or a thin plate of a dielectric material separate from the substrate 100 with a conductive surface formed on at least the lower surface thereof. In the first embodiment, the first member 102 is formed of a ground pattern provided on the lower surface of the substrate 100.

[0032] The MMIC 10 has a large number of terminals. The large number of terminals are arranged, for example, on the bottom surface of the MMIC 10. The large number of terminals include a plurality of pairs of transmitting / receiving terminals 11 for transmitting or receiving high-frequency electromagnetic waves and signal ground terminals 12. In addition, the large number of terminals may include, for example, one or more of an antenna input / output terminal, a power supply terminal, a control terminal, and a shield ground terminal. The MMIC 10 of the first embodiment is configured, for example, in a BGA package, and the large number of terminals are configured as solder ball-type terminals.

[0033] The first waveguide 3 includes a core conductor 300 formed adjacent to the MMIC 10 in a top view, for example, at a position adjacent to the outside of the outline of the MMIC 10, penetrating the substrate 100 and the first member 102 in the vertical direction, and a peripheral conductor 103 formed around the core conductor 300, penetrating the substrate 100 in the vertical direction. Here, "around" refers to a distance within which the core conductor 300 and the peripheral conductor 103 can form a waveguide equivalent to a coaxial waveguide or a triplate strip waveguide. The core conductor 300 and the peripheral conductor 103 are made of a conductor such as copper.

[0034] As an example, the first waveguide 3 of the first embodiment includes a core conductor 300 that is generally circular in top view and six peripheral conductors 103 that are generally circular in top view and arranged around the core conductor 300 along a circle concentric with the core conductor 300. Note that the configuration of the first waveguide 3 is not limited to this. Other configuration examples will be described separately in modified examples. The core conductor 300 can be configured, for example, by embedding a conductor in a through-hole provided in the substrate 100 or by inserting a separate conductor. An upper end 301 of the core conductor 300 is connected to the transmitting / receiving terminal 11 via a feed waveguide 302 provided on the upper surface of the substrate 100. Specifically, one end of the feed waveguide 302 is connected to the transmitting / receiving terminal 11, and the other end is connected to the upper end 301 of the core conductor 300.

[0035] The feed waveguide 302 is composed of a microstrip line formed by a transmission line made of a conductor formed on the upper surface of the substrate 100 and a first member 102 located on the lower surface of the transmission line, sandwiching the substrate 100. That is, a high-frequency electromagnetic field propagates between the transmission line and the first member 102 constituting the ground conductor. Note that although a BGA package is used as an example of the package of the MMIC 10, the configuration of the first embodiment in which connection is made via the feed waveguide 302 can flexibly accommodate not only BGA packages but also other terminal-type packages.

[0036] 3(a) is a top view of the WRG structure 4, FIG. 3(b) is a partial perspective view of the WRG structure 4, and FIG. 3(c) is a partial cross-sectional view taken along line B-B' in FIG. 3(a). As shown in FIGS. 1, 2, and 3(a) to 3(c), the WRG structure 4 includes a second member 200, a plurality of ridges 201 provided on the upper surface of the second member 200, a plurality of rods 202 having conductive surfaces provided adjacent to both sides of each ridge 201, and openings 203 penetrating the second member 200 to the rear surface. The second member 200 has a conductive upper surface 200S, which is a conductive surface formed at least on the upper surface.

[0037] The ridges 201 extend opposite the conductive lower surface 102S, which is the conductive surface on the lower surface of the first member 102, and have a waveguide surface 201S consisting of a strip-shaped conductive upper surface. A plurality of rods 202 are arranged adjacent to at least both sides of each ridge 201, forming an electromagnetic wave shielding wall 210. The electromagnetic wave shielding wall 210 formed by the plurality of conductive rods 202 becomes an artificial magnetic wall. The plurality of rods 202 forming the artificial magnetic wall are called an artificial magnetic conductor. The waffle iron structure of the WRG structure 4 will be described in detail later, so only an overview will be given here.

[0038] In the first embodiment, leakage of a high-frequency electromagnetic field is suppressed by the confinement effect of the electromagnetic wave shielding wall 210 formed by the artificial magnetic conductor. As a result, a second waveguide 5 is formed by the opposing conductive lower surface 102S of the first member 102 and the conductive waveguide surface 201S of the ridge 201, and the high-frequency electromagnetic field is propagated via the second waveguide 5. The multiple rods 202 extend upward from the second member 200. In the examples of FIGS. 3(a) to (c), the multiple rods 202 have approximately the same length (height).

[0039] The conductive lower surface 102S of the first member 102 extends two-dimensionally along a plane (a plane parallel to the XY plane) perpendicular to the axial direction (Z direction) of the rod 202. It is recommended that this range be at least in the region facing the ridge 201 and the rod 202. In the first embodiment, the conductive lower surface 102S is a smooth plane, but the conductive lower surface 102S does not necessarily have to be a smooth plane. Here, in the first embodiment, the space between the conductive lower surface 102S of the first member 102 and the conductive upper surface 200S of the WRG structure 4 is filled with air. Note that the space may be filled with gas, vacuum, or the like, instead of air, or at least a portion of the space may be filled with a dielectric.

[0040] The opening 203 is a hole that penetrates the ridge 201 and the second member 200 from top to bottom, and serves as a waveguide that propagates electromagnetic waves to an antenna radiating element or the like, or as an antenna radiation hole. When the opening 203 is used as an antenna radiation hole, the waveguide device of the present invention can function as a radar device. Note that the arrangements of the ridges, rods, openings, walls, etc. in the drawings in this specification, such as Figures 2 and 3, are illustrative drawings intended only to explain the various components in the waveguide device of the present invention, and are not based on an arrangement intended to achieve a specific function unless explicitly stated.

[0041] 2, the IC mounting substrate 2 and the WRG structure 4 are arranged such that the core conductor 300 of the first waveguide 3 faces the upper waveguide surface 201S adjacent to the front end of the ridge 201. In the example of FIG. 2, the tip of the core conductor 300 is in contact with the waveguide surface 201S. That is, the lower end of the core conductor 300 serves as a feed conductor that feeds electromagnetic waves propagating through the first waveguide 3 to the second waveguide 5. Specifically, the core portion of the core conductor 300 (i.e., the core of the substrate portion) and its lower half serving as a feed conductor (i.e., the portion from the lower end of the substrate to the waveguide surface 201S) (hereinafter referred to as the "lower feed conductor") are continuously formed of the same material. That is, the core conductor 300 according to the first embodiment is made of a core extension conductor, and the lower feed conductor is made of an extended portion of the core. As will be explained in the embodiment below, the core wire of the board portion and the lower power supply conductor may be made of different conductive materials.

[0042] The contact between the lower feed conductor of the core conductor 300 and the waveguide surface 201S can be fixed by soldering, a conductive adhesive, or the like, although not shown. In the present invention, "contact" refers to a state in which two components having conductive surfaces are physically abutted and fixed with screws or the like, two components having conductive surfaces are integrally formed, or two components having conductive surfaces are in contact with each other via a conductive material (including a conductive fixing material such as metal, a conductive adhesive, or a conductive oil) between them, and the two components are electrically connected to each other. The propagation of electromagnetic waves between the first waveguide 3 and the second waveguide 5 does not necessarily require the lower feed conductor to be in contact with the waveguide surface 201S. Specifically, the lower feed conductor and the waveguide surface 201S may be high-frequency coupled without contact. The high-frequency coupling configuration will be described in detail in the sixth modification and the third embodiment.

[0043] Here, the first waveguide 3 is configured to have a function equivalent to a coaxial waveguide or a triplate strip waveguide, and propagates electromagnetic waves fed from the MMIC 10 via the feed waveguide 302. The same applies to electromagnetic waves fed from the second waveguide 5 to the first waveguide 3. High-frequency coupling refers to the phenomenon in which capacitive coupling occurs between the lower feed conductor and the waveguide surface 201S because they are close to each other but not in contact with each other, and coupling occurs in the high-frequency region in the frequency band used (for example, a frequency of around 80 GHz in the case of millimeter-wave radar), resulting in an electrically conductive state. [First connection configuration example]

[0044] Next, a specific example of the connection configuration of each component in the IC mounting substrate 2, including the first waveguides 3, the terminal sets of the MMIC 10, the feed waveguides 302, and the first member 102, will be described. FIG. 4A is a diagram showing a first example of the connection configuration of each component in the IC mounting substrate 2, and is a partial top view of the IC mounting substrate 2 as viewed from the top surface. FIG. 4B is a diagram showing the first example of the connection configuration of each component in the IC mounting substrate 2, and is a partial bottom view of the IC mounting substrate 2 as viewed from the bottom surface. FIG. 4C(a) is a diagram showing the structure of a microstrip line, FIG. 4C(b) is a diagram showing the structure of a coplanar line, and FIG. 4C(c) is a diagram showing the structure of a post-wall waveguide.

[0045] As shown in FIGS. 4A and 4B, the IC mounting substrate 2 is provided with a plurality of first waveguides 3 penetrating the substrate 100 and the first member 102. For ease of explanation, the examples shown in FIGS. 4A and 4B show three first waveguides 3, but in reality, many more first waveguides 3 are provided. The upper end 301 of the core conductor 300 of each first waveguide 3 is electromagnetically connected to each transmitting / receiving terminal 11, which is formed from a BGA terminal of the MMIC 10, by each feeding waveguide 302 formed from a microstrip line. Here, the feeding waveguide 302 corresponds to the upper feeding part 302 described later in FIG. 33. As shown in FIG. 4C(a), the microstrip line is formed from a wiring pattern 302L provided on the upper surface of the substrate 100 and a first member 102 provided on the lower surface of the substrate 100 with the substrate 100 sandwiched therebetween.

[0046] 4A and 4B, each signal ground terminal 12 (hereinafter referred to as "SG terminal 12") of the MMIC 10 is connected to the first member 102 via a peripheral conductor 103 of the first waveguide 3 or a through-hole 104 provided in the substrate 100. In addition, the lower end of the peripheral conductor 103 of each first waveguide 3 is connected to the first member 102. Some of the peripheral conductors 103 are also connected to the ground pattern 101, which is connected to the first member 102 via a through via hole 111. That is, the peripheral conductors 103 and the SG terminal 12 are connected to the first member 102 and have the potential (ground potential) of the first member 102. On the other hand, the core conductor 300 has the potential of the electromagnetic wave supplied from the MMIC 10 via the transmitting / receiving terminal 11 or the electromagnetic wave supplied from the second waveguide 5 to the first waveguide 3. This allows electromagnetic waves to propagate between the core conductor 300 and the peripheral conductor 103 in the first waveguide 3. Note that to prevent a short circuit between the core conductor 300 and the first member 102, an area where no ground pattern (first member 102) is formed is provided around the core conductor 300 on the underside of the substrate 100. In the first embodiment, when forming the ground pattern that becomes the first member 102 on the underside of the substrate 100, an area is formed in accordance with the position of each core conductor 300.

[0047] Furthermore, the feed waveguide 302 is not limited to a microstrip line structure, and may be a coplanar line as shown in FIG. 4C(b) or a post-wall waveguide as shown in FIG. 4C(c). In the case of a coplanar line, the feed waveguide 302 is composed of a wiring pattern 302L provided on the upper surface of the substrate 100 and ground patterns 101 provided on both sides of the wiring pattern 302L on the upper surface of the substrate 100. In the case of a post-wall waveguide, the feed waveguide 302 is composed of the ground pattern 101 and the first member 102 arranged opposite each other across the substrate 100, and two rows of post walls formed between them by arranging a plurality of through holes 104 in two parallel rows that penetrate the substrate 100 from top to bottom. Each through hole 104 is electrically connected to the ground pattern 101 on the upper surface of the substrate 100 and to the first member 102 on the lower surface of the substrate 100. With this configuration, electromagnetic waves propagate between the ground pattern 101 and the first member 102 and between the two rows of post walls. [Second connection configuration example]

[0048] Fig. 5A is a diagram showing a second connection example of each component in IC mounting board 2, and is a partial top view of IC mounting board 2 as seen from the top surface. Fig. 5B is a diagram showing the second connection example of each component in IC mounting board 2, and is a partial bottom view of IC mounting board 2 as seen from the bottom surface. As shown in Figs. 5A and 5B, feed waveguide 302 according to the second connection example has a configuration in which multiple through via holes 105 are provided on both sides of feed waveguide 302 in the longitudinal direction of the transmission line in the first connection example.

[0049] Each through via hole 105 is connected to the first member 102 on the underside of the substrate 100, and each SG terminal 12 of the MMIC 10 can be connected to the first member 102 via the nearest through via hole 105. This eliminates the need to connect to the first member 102 via a peripheral conductor 103 or ground pattern 101, which are located relatively far away, allowing for a compact configuration. Furthermore, the through via holes 105 provided along the longitudinal direction of the feed waveguide 302 can reduce transmission loss of electromagnetic waves. Other connection configurations are the same as those in the first connection configuration example described above. [Effects of the first embodiment]

[0050] As described above, the waveguide device 1 of the first embodiment includes a substrate 100 having an upper surface and a lower surface, an MMIC 10 arranged on the upper surface side of the substrate 100 and having a set of a transmitting / receiving terminal 11 and an SG terminal 12 for transmitting or receiving, a first member 102 arranged along the lower surface side of the substrate 100 and having a conductive lower surface 102S that is electrically connected to the SG terminal 12 of the MMIC 10, a core conductor 300 that passes through the substrate 100 and the first member 102 in the vertical direction, and a peripheral conductor 103 that is arranged around the core conductor 300 along the core conductor 300 with an insulator (dielectric of the substrate 100) interposed therebetween and that is in contact with the conductive lower surface 102S of the first member 102, a first waveguide 3 that includes a second member 200 arranged along the lower surface side of the first member 102 and has a conductive upper surface, and a first member 102 and a second member 200 arranged along the lower surface side of the first member 102 and having a conductive upper surface. the first member 102 and the second member 200, and has a ridge 201 having a waveguide surface 201S which is a strip-shaped conductive upper surface facing the conductive lower surface 102S of the first member 102; a second waveguide 5 constituted by the waveguide surface 201S of the ridge 201 and the conductive lower surface 102S of the first member 102; an electromagnetic wave blocking wall 210 (comprised of a plurality of rods 202) arranged between the first member 102 and the second member 200 and arranged adjacent to the second waveguide 5; a feed waveguide 302 arranged on the upper surface of the substrate 100, and electromagnetically connecting the transmitting / receiving terminal 11 of the MMIC 10 and the end of the core conductor 300 on the upper surface side of the substrate; and a lower feed conductor (composed of the lower end of the core conductor 300) which contacts or high-frequency couples the end of the core conductor 300 on the lower surface side of the first member 102 to one end of the second waveguide 5 arranged below said end. In the waveguide device 1 of the first embodiment, the SG terminal 12 of the MMIC 10 is connected to the conductive lower surface 102S of the first member 102 via the peripheral conductor 103, the through hole 104, or the penetrating via hole 105.

[0051] With the configuration described above, the installation space required for the first waveguide 3 on the substrate 100 can be reduced compared to a conventional configuration in which a rectangular waveguide or the like is formed on a substrate. Specifically, the installation space can be reduced to ½ or less of the free space wavelength λo of the highest frequency of the electromagnetic wave (millimeter wave) propagating through the first waveguide 3. This makes it possible to provide a waveguide device that can connect the transmitting / receiving terminal 11 of a millimeter wave IC (MMIC) and an antenna radiating element in a simple, space-saving, inexpensive, and efficient manner, even when there are a large number of transmitting and receiving channels.

[0052] Furthermore, since the degree of freedom in installation is high and the first waveguide 3 can be formed near the MMIC 10, the distance between the transmitting / receiving terminal 11 and the first waveguide 3 can be shortened compared to conventional cases. This significantly reduces the transmission loss of electromagnetic waves. Furthermore, unlike the conventional rectangular waveguide configuration, the first waveguide 3 is a transmission line type power supply system (non-resonant type), which enables wideband power supply. Furthermore, the configuration of the first waveguide 3 can be configured to have a function equivalent to that of a coaxial waveguide or a triplate strip waveguide, which reduces the loss (dielectric loss angle tanδ) due to the material (dielectric) of the substrate 100. As a result, the transmission loss due to the substrate material can be reduced.

[0053] Furthermore, since the feed path between the transmitting / receiving terminal 11 and the first waveguide 3 is formed by the feed waveguide 302 made of a microstrip waveguide, the position at which the first waveguide 3 is formed can be designed relatively freely. For example, the first waveguide 3 can be formed at a position that matches the arrangement interval of the ridges 201 of the WRG structure 4. This allows the end of the core conductor 300 on the lower surface side of the first member 102 to be in contact with or high-frequency coupled to one end of the second waveguide 5 without bending the ridge 201 side, thereby preventing the WRG structure 4 from becoming complicated and large. Second Embodiment 〔composition〕

[0054] Next, a second embodiment of the present invention will be described. Figs. 6 to 9 are diagrams illustrating the second embodiment. Fig. 6 is a perspective view showing a schematic configuration example of a waveguide device 1A according to the second embodiment. Fig. 7 is a partial cross-sectional view taken along line A-A' in Fig. 6. The second embodiment differs from the first embodiment in that the transmitting / receiving terminal 11 and the SG terminal 12 of the MMIC 10 are connected to the upper ends of the core conductor 300 and the peripheral conductor 103 in a state of contact with each other via connection conductors. Hereinafter, this connection configuration will be referred to as a "direct connection configuration."

[0055] 6 and 7, a waveguide device 1A according to the second embodiment includes an IC mounting substrate 2A instead of the IC mounting substrate 2 and a first waveguide 3A instead of the first waveguide 3 in the waveguide device 1 according to the first embodiment. The IC mounting substrate 2A has a plurality of first waveguides 3A penetrating a substrate 100, and an MMIC 10 is mounted on the upper surface of the substrate 100 so as to cover the plurality of first waveguides 3A from above.

[0056] In the second embodiment, the MMIC 10 has terminals arranged in a grid pattern on the underside of a package such as a BGA package. In the second embodiment, a BGA package is used as an example. The upper ends of the core conductors 300 of the multiple first waveguides 3A are located at positions corresponding to the mounting positions of the transmitting and receiving terminals 11 of the MMIC 10 on the substrate 100. In addition, the upper ends of the peripheral conductors 103 are located at positions corresponding to the mounting positions of the SG terminals 12 of the MMIC 10 on the substrate 100.

[0057] That is, the MMIC 10 is arranged so that each transmitting / receiving terminal 11 and each SG terminal 12 overlaps the upper end of the core conductor 300 and peripheral conductor 103 of each first waveguide 3A. Note that it may be difficult to arrange all of the SG terminals 12 at positions that overlap the upper end of the peripheral conductor 103, depending on the configuration and number of the peripheral conductors 103. Therefore, a configuration may be adopted in which the SG terminals 12 are connected to each other by a wiring pattern on the substrate 100 or the like, so that they can be connected to the peripheral conductor 103 even if they do not overlap. In the second embodiment, each transmitting / receiving terminal 11 and each SG terminal 12 are connected in contact with the upper end of the core conductor 300 and peripheral conductor 103 by a connecting conductor such as solder. Hereinafter, this connection configuration may be referred to as a "direct connection configuration."

[0058] The MMIC 10 employs a BGA package, with each terminal being a solder ball. Therefore, the transmit / receive terminals 11 can be directly connected to the upper ends of the core conductors 300 by reflow soldering using these solder balls as connecting conductors. Similarly, the SG terminals 12 can be directly connected to the upper ends of the peripheral conductors 103 by reflow soldering. Note that as long as the upper ends of the core conductors 300 and peripheral conductors 103 can be positioned at the mounting locations of the transmit / receive terminals 11 and SG terminals 12 of the MMIC 10, packages with other terminal shapes, such as lead and pad types, can be used. However, a grid-like arrangement of terminals on the underside of an IC package, such as a BGA or PGA, allows for a compact configuration of the MMIC 10 itself, which is effective in preventing the device from becoming larger due to the larger ICs used in multi-channel applications. BGAs are available with a variety of terminal center distances, such as 0.65 mm, 0.8 mm, and 1.0 mm. In order to prevent the device from becoming larger, it is effective to use one with as short a center-to-center distance as possible, but it is necessary to design the diameter of the core conductor 300 to match this center-to-center distance and to configure the position so that the core conductor 300 and the peripheral conductor 103 are not connected to the transmitting / receiving terminal 11 at the same time. [First direct connection configuration example]

[0059] Next, we will explain an example of a direct coupling configuration that is effective for a configuration in which terminals can be arranged in a grid pattern on the underside of the package of the MMIC 10, such as a BGA. FIG. 8A is a partial cross-sectional view showing a first example of a direct coupling configuration between the transmitting / receiving terminal 11 and the core conductor 300. FIG. 8A is a cross-sectional view viewed from the opposite side from the view point of FIG. 7. In the first example of a direct coupling configuration, as shown in FIG. 8A, IC pins are attached to the transmitting / receiving terminals 11 of the MMIC 10 as the core conductors 300. The IC pins are attached to each transmitting / receiving terminal 11 before the MMIC 10 is mounted on the substrate 100. The IC pins are then inserted into through-holes 100h formed vertically through the substrate 100 and the first member 102 to form the core conductors 300. Note that the SG terminal 12 of the MMIC 10 may also be similarly configured to have an IC pin attached as a peripheral conductor 103. In this case, the IC pins are shorter than the IC pins of the core conductors 300. In this case, as in the first embodiment, the lower end of the IC pin as the core conductor 300 serves as the lower feed conductor, and in the example of Fig. 8A, the lower end of the lower feed conductor is in contact with the waveguide surface 201S. Note that, as in the first embodiment, the lower feed conductor may be disposed in a position close to but not in contact with the second waveguide 5 to achieve high-frequency coupling. [Second direct connection configuration example]

[0060] FIG. 8B is a partial cross-sectional view showing a second example of a direct connection between the transmitting / receiving terminal 11 and the core conductor 300. FIG. 8B is a cross-sectional view taken from the opposite side of FIG. 7. In the second example of a direct connection, as shown in FIG. 8B, the MMIC 10 is mounted on the substrate 100 via the IC socket 14. In addition, IC pins serving as the core conductor 300 are attached by soldering or the like to terminals 11' of the IC socket 14 corresponding to the transmitting / receiving terminals 11 of the MMIC 10. The IC pins are attached to the terminals 11' before the IC socket 14 is mounted on the substrate 100, and the IC pins are inserted into through-holes 100h formed vertically through the substrate 100 and the first member 102 to form the core conductors 300. Note that a similar configuration may be adopted in which IC pins serving as peripheral conductors 103 are attached by soldering or the like to terminals 12' of the IC socket 14 corresponding to the SG terminals 12 of the MMIC 10. In this case, an IC pin shorter than the IC pin of the core conductor 300 is attached. In this case, as in the first embodiment, the lower end of the IC pin serving as the core conductor 300 serves as the lower feed conductor, and in the example of Fig. 8B, the lower end of the lower feed conductor is in contact with the waveguide surface 201S. Note that, as in the first embodiment, the lower feed conductor may be disposed in a position close to but not in contact with the second waveguide 5 to achieve high-frequency coupling. [Example of Ridge 201 layout structure]

[0061] Next, an example of the arrangement of the tip of the ridge 201 in a direct-coupled configuration will be described. FIG. 9 is a schematic diagram showing an example of the arrangement of the tip of the ridge 201 in a direct-coupled configuration. FIG. 9 shows a simplified example of the arrangement of the tip of the ridge 201 relative to each transmitting / receiving terminal 11 of the MMIC 10 when the WRG structure 4 is viewed from the bottom, with some components omitted. As indicated by the dashed circles in FIG. 9, the MMIC 10 has a large number of solder ball-type terminals arranged in a grid pattern. In the example of FIG. 9, the MMIC 10 has a transmitting section (TX) 15, a receiving section (RX) 16, and a heat sink 17.

[0062] The transmitter 15 transmits high-frequency electromagnetic waves generated by the MMIC 10 via the transmitter / receiver terminal 11. The receiver 16 receives electromagnetic waves fed via, for example, the first waveguide 3A. The heat sink 17 includes a ball terminal (thermal ball) that dissipates heat from the IC to the outside. Each transmitter / receiver terminal 11 of the transmitter 15 is directly connected to the upper end of the core conductor 300 of the first waveguide 3, so that the core conductor 300 extends straight from directly below the transmitter / receiver terminal 11. However, as shown in the example of FIG. 9 , there are cases where the arrangement width W1 of the ridge 201 of the WRG structure 4 is smaller than the arrangement width W2 of the transmitter / receiver terminal 11. In such cases, it is difficult to align the lower end of the core conductor 300 with the waveguide surface 201S of the ridge 201 when using a linear ridge 201. This situation may occur when W2 is set to a relatively small value, such as 0.65 mm. Therefore, in the second embodiment, as shown in the example of FIG. 9, the front end of the ridge 201 is bent toward the lower end of the core conductor 300. This allows the positional relationship to be aligned. However, this configuration is not limiting, and W2 can also be aligned with W1 to correspond to a linear ridge 201. [Effects of the second embodiment]

[0063] As described above, the waveguide device 1A of the second embodiment includes a first waveguide 3A including a substrate 100 having an upper surface and a lower surface, an MMIC 10 arranged on the upper surface side of the substrate 100 and having a set of a transmitting / receiving terminal 11 and an SG terminal 12 for transmitting or receiving, a first member 102 arranged along the lower surface side of the substrate 100 and having a conductive lower surface 102S that is electrically connected to the SG terminal 12 of the MMIC 10, a core conductor 300 that passes through the substrate 100 and the first member 102 in the vertical direction, and a peripheral conductor 103 that is arranged around the core conductor 300 along the core conductor 300 with an insulator (dielectric of the substrate 100) interposed therebetween and in contact with the conductive lower surface 102S of the first member 102, a second member 200 arranged along the lower surface side of the first member 102 and having a conductive upper surface, and a second member 200 arranged between the first member 102 and the second member 200 and having a conductive upper surface of the first member 102. 33 ))。 The first member 102 includes a ridge 201 having a waveguide surface 201S, which is a strip-shaped conductive upper surface facing the conductive lower surface 102S; a second waveguide 5 formed by the waveguide surface 201S of the ridge 201 and the conductive lower surface 102S of the first member 102; an electromagnetic wave shielding wall 210 (made up of a plurality of rods 202) arranged between the first member 102 and the second member 200 and adjacent to the second waveguide 5; a connecting conductor (made up of a solder ball of the BGA terminal corresponding to the transmitting and receiving terminal 11 and corresponding to the upper feeding part 302 in Figure 33 ) that fixes the transmitting and receiving terminal 11 of the MMIC 10 and the end of the core conductor 300 on the upper surface side of the substrate in a state of contact with each other on the upper surface of the substrate 100; and a lower feeding conductor (made up of the lower end of the core conductor 300) that contacts or high-frequency couples the end of the core conductor 300 on the lower surface side of the first member 102 with one end of the second waveguide 5 arranged below the end. In the waveguide device 1A of the second embodiment, the SG terminal 12 of the MMIC 10 is connected to the conductive lower surface 102S of the first member 102 via the peripheral conductor 103.

[0064] In addition to the effects of the first embodiment, the configuration described above allows the transmitting / receiving terminal 11 and the first waveguide 3 to be directly connected, thereby significantly reducing the transmission loss of electromagnetic waves. Furthermore, the space required to connect the transmitting / receiving terminal 11 and the first waveguide 3 can be significantly reduced, thereby enabling further miniaturization of the device. In the second embodiment, an IC pin is bonded to the solder ball-type transmitting / receiving terminal 11 of the BGA package, and this IC pin serves as the core conductor 300. This allows the core conductor 300 of the first waveguide 3A to be formed through a relatively simple procedure, such as inserting an IC pin previously bonded to a ball terminal into a through-hole provided in the substrate 100. The same applies to a configuration in which an IC pin is bonded to a terminal of the IC socket 14 corresponding to the transmitting / receiving terminal 11, and this IC pin serves as the core conductor 300. [Modification 1 of the first and second embodiments]

[0065] Next, Modification 1 of the first and second embodiments will be described. Fig. 10A and Fig. 10B are drawings showing Modification 1. Fig. 10A(a) to (h) are top views showing structural examples of the first waveguide 3 according to Modification 1. Note that the structural examples shown in Fig. 10A(a) to (h) are structural examples common to the first waveguides 3 and 3A, and therefore will be described below as structural examples of the first waveguide 3 without distinguishing between them. That is, the core conductor 300 and the peripheral conductor 103 of the first waveguide 3 according to the first and second embodiments can have any of the structures shown in Fig. 10A(a) to (h). [Variation 1-1]

[0066] First, a description will be given of Modification 1-1 of the first waveguide 3 shown in Fig. 10A(a). The first waveguide 3 according to Modification 1-1 is provided so as to penetrate the substrate 100 and the first member 102 in the vertical direction. The same applies to the structural examples of Figs. 10A(b) to (h), so the description will be omitted as appropriate.

[0067] As shown in FIG. 10A(a), the first waveguide 3 according to Modification 1-1 includes a core conductor 300 that is elliptical in top view and one peripheral conductor 103 that is rectangular in top view and adjacent to the core conductor 300 with a predetermined gap therebetween. The peripheral conductor 103 is connected to a first member 102. That is, the first waveguide 3 according to Modification 1-1 includes the core conductor 300 in the shape of an elliptical cylinder and one peripheral conductor 103 that is plate-shaped and adjacent to the core conductor 300 with a predetermined gap therebetween, with the dielectric of the substrate 100 sandwiched between them. In the example shown in FIG. 10A(a), the core conductor 300 is elliptical with its major axis in the Y direction and its minor axis in the X direction, and the peripheral conductor 103 is rectangular with its major side in the Y direction and its minor side in the X direction. The peripheral conductor 103 is adjacent to the core conductor 300 on the −X direction side. Although the shape of the core conductor 300 may be a perfect circle when viewed from above, an elliptical shape increases the area facing the peripheral conductor 103, thereby increasing transmission efficiency. The predetermined interval is designed to be an appropriate interval depending on factors such as impedance matching with the second waveguide 5. This also applies to the structural examples of FIGS. 10A(b) to (h). With this configuration, electromagnetic waves can propagate between the elliptical cylindrical core conductor 300 and one plate-like peripheral conductor 103. [Variation 1-2]

[0068] Next, a modified example 1-2 of the first waveguide 3 shown in Fig. 10A(b) will be described. As shown in Fig. 10A(b), the first waveguide 3 according to this modified example 1-2 has a configuration in which a peripheral conductor 103 having the same shape as that of modified example 1-1 is arranged adjacent to the core conductor 300 on the +X-direction side. That is, the core conductor 300 is sandwiched between the two peripheral conductors 103 on both sides in the X-direction. With this configuration, the first waveguide 3 can propagate electromagnetic waves between the elliptical cylindrical core conductor 300 and the two plate-like peripheral conductors 103. [Variation 1-3]

[0069] Next, Modification 1-3 of the first waveguide 3 shown in Fig. 10A(c) will be described. As shown in Fig. 10A(c), the first waveguide 3 according to Modification 1-3 has a configuration similar to that of Modification 1-2, except that the peripheral conductors 103 having the shape of Modification 1-1 are arranged adjacent to the core conductor 300 on both sides in the +Y and -Y directions, rotated by 90° around the Z axis. That is, the core conductor 300 is sandwiched between the four peripheral conductors 103 on both sides in the X and Y directions. With this configuration, the first waveguide 3 can propagate electromagnetic waves between the elliptical cylindrical core conductor 300 and the four plate-like peripheral conductors 103. [Variation 1-4]

[0070] Next, a modified example 1-4 of the first waveguide 3 shown in FIG. 10A(d) will be described. The first waveguide 3 according to this modified example 1-4 has a structure similar to that of the first waveguides 3 and 3A according to the first and second embodiments. Specifically, the first waveguide 3 according to this modified example 1-4 includes a core conductor 300 that is elliptical in top view and six peripheral conductors 103 that are circular in top view and arranged concentrically around the core conductor 300. The six peripheral conductors 103 are arranged in opposing positions in the X direction, with three on the −X-direction side of the core conductor 300 and three on the +X-direction side. With this configuration, the first waveguide 3 can propagate electromagnetic waves between the elliptical cylindrical core conductor 300 and the six circular cylindrical peripheral conductors 103. Note that the core conductor 300 may also be circular in top view. [Variation 1-5]

[0071] Next, a modified example 1-5 of the first waveguide 3 shown in Fig. 10A(e) will be described. As shown in Fig. 10A(e), the first waveguide 3 according to this modified example 1-5 has a configuration in which the number of peripheral conductors 103 in the above modified example 1-4 is increased from six to ten. With this configuration, the first waveguide 3 forms a waveguide closer to a coaxial waveguide, and electromagnetic waves can propagate between the elliptical cylindrical core conductor 300 and the ten circular cylindrical peripheral conductors 103. Note that the core conductor 300 may have a circular shape when viewed from above. [Variation 1-6]

[0072] Next, a modified example 1-6 of the first waveguide 3 shown in Fig. 10A(f) will be described. As shown in Fig. 10A(f), the first waveguide 3 according to this modified example 1-6 has a configuration in which the three peripheral conductors 103 on the +X direction side are deleted from the above modified example 1-4. With this configuration, the first waveguide 3 can propagate electromagnetic waves between the elliptical cylindrical core conductor 300 and the three circular cylindrical peripheral conductors 103. Note that the core conductor 300 may have a circular shape when viewed from above. [Variation 1-7]

[0073] Next, Modification 1-7 of the first waveguide 3 shown in FIG. 10A(g) will be described. As shown in FIG. 10A(g), the first waveguide 3 according to Modification 1-7 has a configuration similar to that of Modification 1-1, except that the core conductor 300 has a rectangular shape in top view. That is, the core conductor 300 is configured in a plate shape. In the example shown in FIG. 10A(g), the thickness of the core conductor 300 is greater than the thickness of the peripheral conductor 103. This configuration allows electromagnetic waves to propagate between the plate-shaped core conductor 300 and one plate-shaped peripheral conductor 103. By making the core conductor 300 plate-shaped, the opposing area with the peripheral conductor 103 can be increased, thereby improving transmission efficiency. The configuration in which the core conductor 300 is plate-shaped can also be applied to other configurations, such as that shown in FIG. 10A(b). [Variation 1-8]

[0074] Next, a modified example 1-8 of the first waveguide 3 shown in Fig. 10A(h) will be described. As shown in Fig. 10A(h), the first waveguide 3 according to this modified example 1-8 has a configuration in which a core conductor 300 having an elliptical shape in top view is arranged in the center of a through hole having an elliptical shape in top view, and a peripheral conductor 103 having an elliptical cylindrical shape is arranged on the inner periphery of the through hole. A space filled with air (insulator) is formed between the core conductor 300 and the peripheral conductor 103, thereby forming a coaxial waveguide. Note that the through hole and the core conductor 300 may also have a perfect circular shape in top view.

[0075] Next, a specific configuration example of Modification 1-8 will be described with reference to FIG. 10B. FIG. 10B is a partial cross-sectional view showing a specific configuration example of FIG. 10A(h). FIG. 10B is a cross-sectional view viewed from the opposite side to that of FIG. 7. As shown in FIG. 10B, the first waveguide 3 according to Modification 1-8 can be applied to a configuration (see FIG. 8A) in which an IC pin is bonded to a solder ball-type transmitting / receiving terminal 11 of an MMIC 10. Specifically, a through hole 100h is formed vertically penetrating the substrate 100 and the first member 102, and a peripheral conductor 103 is disposed cylindrically on the inner wall of the through hole 100h by coating or the like. The lower end of the peripheral conductor 103 is connected to the first member 102. An IC pin serving as a core conductor 300 is inserted through the center of the through hole 100h. The diameter of the through hole 100h and the diameter of the IC pin are designed so that the core conductor 300 and the peripheral conductor 103 do not come into contact with each other. The structure of the first waveguide 3 is not limited to the structures of the above-described modified examples 1-1 to 1-8. For example, in the structure of Fig. 10A(c), one of the four rectangular peripheral conductors 103 facing each other in the X direction or the Y direction may be configured as a peripheral conductor 103 having a perfect circular or elliptical shape when viewed from above, or a structure combining a plurality of types of conductor shapes may be used. [Modification 2 of the First and Second Embodiments]

[0076] Next, Modification 2 of the first and second embodiments will be described. Figures 11 to 13 are drawings showing Modification 2. Note that although Figures 11 to 13 illustrate a configuration in which the configuration of Modification 2 is applied to the waveguide device 1 of the first embodiment, Modification 2 is a configuration that can be applied to both the waveguide devices 1 and 1A of the first and second embodiments. Below, we will explain the case in which Modification 2 is applied to the waveguide device 1 as a representative example. [Variation 2-1]

[0077] First, a first configuration example of the ridge contact configuration according to Modification 2-1 will be described with reference to FIG. 11A. As shown in FIG. 11A, the waveguide device 1 according to the first configuration example includes, as a first waveguide 3, a core conductor 300 and a lower feed conductor 303 configured separately from the core conductor 300. Additionally, a peripheral conductor 103 is provided adjacent to the core conductor 300 with a predetermined gap therebetween when viewed from above. A recess 300s is provided in the center of the lower end of the core conductor 300. The lower feed conductor 303 has a tapered shape (frustum shape) tapering toward the upper end. The upper end of the lower feed conductor 303 is inserted into the recess 300s and is in contact with the lower end of the core conductor 300 by soldering, a conductive adhesive, or the like, and is fixed in an electrically conductive state. On the other hand, the lower end of the lower feed conductor 303 is fixed by soldering, a conductive adhesive, or the like onto the waveguide surface 201S facing the lower end of the lower feed conductor 303 of the ridge 201. With this configuration, the electromagnetic wave propagating from above to below through the first waveguide 3 is propagated in the second waveguide 5 in a direction along the longitudinal direction of the ridge 201. [Variation 2-2]

[0078] Next, a second configuration example of the ridge contact configuration according to Modification 2-2 will be described with reference to FIG. 11B. As shown in FIG. 11B, the waveguide device 1 according to the second configuration example includes, as the first waveguide 3, a core conductor 300 and a lower feed conductor 303A that is separate from the core conductor 300. Additionally, the waveguide device 1 includes a peripheral conductor 103 that is adjacent to the core conductor 300 with a predetermined gap therebetween when viewed from above. The lower feed conductor 303A has a configuration that is upside down compared to the lower feed conductor 303 of Modification 2-1. The upper end of the lower feed conductor 303A is fixed to the lower surface of the substrate 100 by soldering, a conductive adhesive, or the like in a state of electrical continuity with the lower end of the core conductor 300. Meanwhile, in WRGB4, a recess 201c for inserting the lower feed conductor 303A is provided on the waveguide surface 201S that faces the lower end of the lower feed conductor 303A of the ridge 201. The lower end of the lower power supply conductor 303A is inserted into the recess 201c, and at least a part of the inserted portion is in contact with the inner periphery of the recess 201c. Note that the lower power supply conductor 303A has a tapered shape, which makes it easy to insert into the recess 201c.

[0079] The lower feed conductor 303A may be simply inserted into the recess 201c, or may be fixed with a conductive adhesive or the like. The depth of the recess 201c and the insertion length of the lower feed conductor 303A are designed to be appropriate for high propagation efficiency, taking into account the matching relationship between the characteristic impedance and the second waveguide 5. The lower feed conductor 303A has a tapered shape. However, this configuration is not limited thereto. For example, the lower feed conductor 303A may be cylindrical, and the recess 201c may be tapered so that its diameter increases from bottom to top. In this case, the core conductor 300 and the lower feed conductor 303A may be integrally formed into a cylindrical shape with the same diameter. Alternatively, the recess 201c may be tapered while the lower feed conductor 303A remains tapered. Here, the electromagnetic wave propagating from top to bottom through the first waveguide 3 propagates in the second waveguide 5 in a direction along the longitudinal direction of the ridge 201. With this configuration, while the lower end of the lower feed conductor 303A is inserted into the recess 201c (i.e., inside the recess 201c), the propagation direction of the electromagnetic wave can be changed and propagated toward the second waveguide 5. This improves the transmission efficiency of the electromagnetic wave compared to a configuration in which the lower end of the lower feed conductor 303A is simply in contact with the waveguide surface 201S of the ridge 201.

[0080] Furthermore, when the core conductor 300 and the lower feed conductor are configured separately, as in the case of the lower feed conductor 303A, multiple lower feed conductors 303A are inserted into the recesses 201c of multiple ridges 201. In this case, as shown in FIG. 12 , the inserted multiple lower feed conductors 303A can be restrained by a restraining member 400 made of an insulating material such as a resin material. The restraining member 400 is designed to restrain the multiple lower feed conductors 303A in a state where they can be inserted into the respective recesses 201c simultaneously. This configuration can reduce the number of steps required to insert the multiple lower feed conductors 303A into the respective recesses 201c. [Variation 2-3]

[0081] Next, a third configuration example of the ridge contact configuration according to Modification 2-3 will be described with reference to FIG. 13 . As shown in FIG. 13 , the waveguide device 1 according to the third configuration example includes a core conductor 300 and a lower feed conductor 304, which is configured separately from the core conductor 300, as the first waveguide 3. Additionally, a peripheral conductor 103 is provided adjacent to the core conductor 300 with a predetermined gap therebetween when viewed from above. A portion of the lower feed conductor 304 is disposed inside the lower end of the core conductor 300, and the other portion protrudes downward from the core conductor 300. The upper end of the lower feed conductor 304 is biased downward by an elastic member such as a coil spring. The lower feed conductor 304 is supported by a stopper (not shown) to prevent it from slipping off the core conductor 300. The core conductor 300 and the lower feed conductor 304 configured as described above can be configured, for example, by a spring connector. The lower end of the lower feed conductor 304 is pressed by the elastic member into contact with the waveguide surface 201S that faces the lower end of the lower feed conductor 304 of the ridge 201. With this configuration, the elastic force of the elastic member can strengthen the contact state between the lower feed conductor 304 and the waveguide surface 201S, so that the manufacturing process can omit a step of fixing the lower feed conductor to the waveguide surface 201S by soldering or the like. [Modification 3 of the first and second embodiments] Next, a third modification of the first and second embodiments will be described. Figures 14A to 16B are drawings showing this third modification. Below, a case where this modification is applied to the waveguide device 1 will be described as a representative example. [Variation 3-1]

[0082] First, a first configuration example of the ridge contact configuration according to Modification 3-1 will be described with reference to FIGS. 14A and 15A. The waveguide device 1 according to this configuration example includes a core conductor 305 instead of the core conductor 300 of the first embodiment. As shown in FIGS. 14A and 15A, the core conductor 305 has a rod-like configuration and is integrated with the lower feed conductor. That is, the core conductor 305 serves as a core extension conductor, similar to the core conductor 300 of the first embodiment. The lower end of the core conductor 305 is fixed to the waveguide surface 201S at one longitudinal end of the ridge 201 by, for example, soldering or a conductive adhesive. In the example shown in FIG. 15A, a through hole 100h for the core conductor is formed through the substrate 100 and the first member 102 at a position directly below the other end of the feed waveguide 302. The core conductor 305 is inserted into the through-hole 100h from below with its lower end fixed on the waveguide surface 201S, and its upper end is connected to the other end of the feed waveguide 302. The connection between the upper end and the other end can be performed by, for example, soldering (reflow) or a conductive adhesive.

[0083] When this configuration example is applied to the waveguide device 1A of the second embodiment, a through hole 100h is provided directly below the transmitting / receiving terminal 11 of the MMIC 10. The core conductor 305 has a tapered shape (frustum shape) tapering toward the upper end, making it easy to insert into the through hole 100h on the substrate 100 side. The core conductor 305 may be formed simultaneously with the formation of the ridge 201 of the WRG structure 4. Alternatively, the core conductor 305 may be formed in a cylindrical shape instead of a tapered shape, and the through hole 100h on the substrate 100 side may be tapered toward the upper end. With this configuration, the core conductors 305 fixed to the multiple ridges 201, respectively, can be inserted into the respective through holes 100h of the IC mounting substrate 2, thereby facilitating connection between the core conductors 305 and the ridges 201. [Variation 3-2]

[0084] Next, a second configuration example of the ridge contact configuration according to Modification 3-2 will be described with reference to FIGS. 14B and 15B. The waveguide device 1 according to this configuration example includes a core conductor 306 instead of the core conductor 300 of the first embodiment. As shown in FIGS. 14B and 15B, the core conductor 306 is similar to the core conductor 305 of Modification 3-1 except for a partial shape difference. Specifically, the core conductor 306 includes an upper portion 306a that is tapered (frustum-shaped) toward the upper end and a cylindrical lower portion 306b. The diameter of the lower end of the upper portion 306a is smaller than the diameter of the lower portion 306b. The diameter of the lower portion 306b is larger than the diameter of the through hole 100h for the core conductor provided in the IC mounting substrate 2. 15B, when core conductor 306 is inserted into through hole 100h provided in IC mounting board 2, the upper end of lower part 306b abuts against the lower surface of board 100, preventing further insertion of core conductor 306. In addition to the effect of modification 3-1, core conductor 306 according to modification 3-2 has lower part 306b that acts as a stopper to prevent core conductor 306 from being inserted too far during manufacturing. [Variation 3-3]

[0085] Next, a third configuration example of the ridge contact configuration according to Modification 3-3 will be described with reference to FIG. 15C . The waveguide device 1 according to this configuration example includes, as a first waveguide 3, a core conductor 300 and a lower feed conductor 307 configured separately from the core conductor 300, and a WRG structure 4A instead of the WRG structure 4 of the first embodiment. The core conductor 300 according to this configuration example has the same shape as the core conductor 300 of the first and second embodiments, but is shorter than the core conductor 300. Specifically, it has a length approximately equal to the thickness of the substrate 100. The lower feed conductor 307 has a cylindrical shape with a diameter smaller than that of the core conductor 300. The upper end of the lower feed conductor 307 is fixed to the lower surface of the core conductor 300 by soldering, a conductive adhesive, or the like, in a state of electrical continuity with the core conductor 300. On the other hand, the WRG structure 4A has a through hole 204 that passes through the ridge 201 and the second member 200 in the vertical direction at a position opposite to the lower end of the lower feed conductor 307. The diameter of the through hole 204 is configured to be slightly larger than the diameter of the lower feed conductor 307. The inner diameter of the through hole 204 has a length that is less than half the wavelength λ of the electromagnetic wave propagating through the second waveguide 5.

[0086] The lower end of the lower feed conductor 307 is inserted into the through hole 204, and its lower end reaches the lower end of the through hole 204. That is, the length of the lower feed conductor 307 is such that its lower end reaches the lower end of the through hole 204. Furthermore, the outer periphery of the lower end of the lower feed conductor 307 inserted into the through hole 204 contacts the inner periphery of the through hole 204. That is, the lower feed conductor 307 and the ridge 201 are electrically connected. With this configuration, the lower end of the lower feed conductor 307 is inserted into the through hole 204 (i.e., inside the through hole 204), and the propagation direction of the electromagnetic wave can be changed toward the second waveguide 5 and propagated therethrough. This improves the transmission efficiency of the electromagnetic wave compared to when the lower end of the lower feed conductor is simply in contact with the waveguide surface 201S of the ridge 201. Furthermore, since the inner diameter of the through-hole 204 is less than half the wavelength λ, it is possible to prevent the electromagnetic waves propagating from the first waveguide 3 from passing through the through-hole 204 and being emitted to the outside. [Variation 3-4]

[0087] Next, a fourth configuration example of the ridge contact configuration according to Modification 3-4 will be described with reference to FIG. 15D . The waveguide device 1 according to this configuration example includes a lower feed conductor 307S instead of the lower feed conductor 307 in the waveguide device 1 of Modification 3-3. The lower feed conductor 307S is separate from the core conductor 300. The lower feed conductor 307S has the same shape as the lower feed conductor 307, except that it is shorter than the lower feed conductor 307 of Modification 3-3. Furthermore, a through hole 204 that vertically penetrates the ridge 201 and the second member 200 is provided at a position facing the lower end of the lower feed conductor 307S of the WRG structure 4A. The lower end of the lower feed conductor 307S is inserted into the through hole 204, and its lower end is located above the lower end of the through hole 204. Furthermore, the side surface of the lower end of the lower power supply conductor 307S inserted into the through hole 204 is in a position near the inner periphery of the through hole 204 and is in a state of not contacting the inner periphery. However, the lower end of the lower power supply conductor 307S is connected to the second member 200 by the solder 401. That is, the lower power supply conductor 307S and the ridge 201 are electrically connected to each other.

[0088] With this configuration, the propagation direction of the electromagnetic wave can be changed to the direction toward the second waveguide 5 while the lower end of the lower feed conductor 307S is inserted into the through hole 204 (i.e., inside the through hole 204). This improves the transmission efficiency of the electromagnetic wave compared to when the lower end of the lower feed conductor is simply brought into contact with the waveguide surface 201S of the ridge 201. Furthermore, since the lower feed conductor 307S and the ridge 201 are electrically connected, the transmission efficiency of the electromagnetic wave can be improved more than when they are close to each other but not in contact with each other. [Variation 3-5]

[0089] Next, a fifth configuration example of the ridge contact configuration according to Modification 3-5 will be described with reference to FIG. 16A . The waveguide device 1 according to this configuration example includes, as the first waveguide 3, a core conductor 300A and a bottom feed conductor 305S that is separate from the core conductor 300A. The core conductor 300A has the same shape as the core conductor 300 of the first and second embodiments, but is shorter than the core conductor 300. Specifically, the core conductor 300A has a length that is shorter than the thickness of the substrate 100. The bottom feed conductor 305S is separate from the core conductor 300A and has the same shape as the core conductor 305 of Modification 3-1. However, it is shorter in length and diameter than the core conductor 305.

[0090] In the example of FIG. 16A , the upper end of the core conductor 300A is connected to the other end of the feed waveguide 302, and the lower end is located at the vertical center of the through hole for the core conductor. That is, the lower half of the core conductor 300 is cut away. Similar to the core conductor 305 of Variation 3-1, the lower end of the lower feed conductor 305S is fixed to the waveguide surface 201S at one longitudinal end of the ridge 201 by, for example, soldering or a conductive adhesive. The upper end of the lower feed conductor 305S is inserted into the through hole of the substrate 100, and the upper end contacts the lower end of the core conductor 300A. The lower end of the core conductor 300A and the upper end of the lower feed conductor 305S may be fixed by, for example, soldering or a conductive adhesive. The lower feed conductor 305S may be formed simultaneously with the formation of the ridge 201 of the WRG structure 4. With this configuration, by inserting multiple lower power supply conductors 305S fixed to multiple ridges 201, respectively, into the respective through holes of the IC mounting substrate 2, the core conductor 300A can be easily connected to the lower power supply conductors 305S and the ridges 201. [Variation 3-6]

[0091] Next, a sixth configuration example of the ridge contact configuration according to Modification 3-6 will be described with reference to FIG. 16B . The waveguide device 1 according to this configuration example includes a core conductor 300A and a lower feed conductor 306S instead of the core conductor 300. The core conductor 300A has the same shape and arrangement as in Modification 3-5. The lower feed conductor 306S is configured separately from the core conductor 300A and has the same shape as the core conductor 306 in Modification 3-2. However, it is shorter and has a smaller diameter than the core conductor 306. The lower feed conductor 306S has a truncated cone-shaped upper portion 306Sa and a cylindrical lower portion 306Sb, similar to the upper portions 306a and 306b of the core conductor 306 in Modification 3-2. The lower end of the lower portion 306Sb is fixed to the waveguide surface 201S at one longitudinal end of the ridge 201 by, for example, soldering or a conductive adhesive.

[0092] The upper portion 306Sa of the lower feed conductor 306S is inserted into the through-hole of the substrate 100, and its upper end contacts the lower end of the core conductor 300A. In this state, the upper end of the lower portion 306Sb abuts against the lower surface of the substrate 100, preventing the lower feed conductor 306S from being inserted any further. The lower end of the core conductor 300A and the upper end of the lower feed conductor 306S may be fixed by, for example, soldering or a conductive adhesive. The lower feed conductor 306S may also be formed simultaneously with the formation of the ridge 201 of the WRG structure 4. With this configuration, in addition to the effects of the above-described Modification 3-5, the lower portion 306Sb of the lower feed conductor 306S acts as a stopper to prevent the lower feed conductor 306S from being inserted too far during manufacturing. [Modification 4 of the First and Second Embodiments]

[0093] Next, Modification 4 of the first and second embodiments will be described. Figures 17 to 18 are drawings showing Modification 4. Although Figures 17 to 18 show an example in which Modification 4 is applied to the waveguide device 1 of the first embodiment, Modification 4 is applicable to both the waveguide devices 1 and 1A of the first and second embodiments. Below, we will describe the case in which Modification 4 is applied to the waveguide device 1 as a representative example.

[0094] As shown in FIG. 17(b), the waveguide device 1 according to the fourth modification includes a first waveguide 3B and a WRG structure 4A instead of the first waveguide 3 and the WRG structure 4 of the first embodiment. The first waveguide 3B according to the fourth modification includes a core conductor 309 and a peripheral conductor 103. As shown in FIG. 17(a), the core conductor 309 has a cylindrical upper portion 309a with a height h1 and a cylindrical lower portion 309b with a height h2 that is larger in diameter and longer than the upper portion 309a. The lower portion 309b corresponds to the lower feed conductor 303 in FIG. 33. The WRG structure 4A according to the fourth modification includes a through-hole 204 that vertically penetrates the ridge 201 and the second member 200 at one end on the front side of the ridge 201. Furthermore, a thick portion 201t that protrudes upward and has a rectangular shape when viewed from above is provided on the waveguide surface 201S adjacent to the rear side of the through-hole 204 of the ridge 201. This thick portion 201t forms a step on the waveguide surface 201S of the ridge 201. The thick portion 201t is provided to achieve a matching (impedance matching) state that minimizes reflection of electromagnetic waves at the connection between the first waveguide 3B and the second waveguide 5. An upper portion 309a of the core conductor 309 is inserted into a through-hole provided in the substrate 100, and the upper end of the upper portion 309a contacts the other end of the feed waveguide 302, although this is not shown.

[0095] Meanwhile, a portion of the lower portion 309b of the core conductor 309 is inserted from above along the side surface of the through hole 204 on the ridge 201 side. That is, the outer periphery of the inserted portion of the lower portion 309b contacts the inner periphery of the through hole 204. The length h3 of the lower portion 309b inserted into the through hole 204 is set to an appropriate length that enables matching of the connection between the first waveguide 3B and the second waveguide 5 according to Modification 4. The portion of the through hole 204 below the lower portion 309b of the core conductor 309 is filled with a conductor 500 such as aluminum, and the lower end of the lower portion 309b is in contact with this conductor. Note that this configuration is not limited to this, and a configuration without filling with the conductor 500 may also be used. With this configuration, it can be seen that, as shown in FIGS. 18(a) to 18(d), electromagnetic waves from the MMIC 10 propagate through the first waveguide 3B from above to below the substrate 100 with sufficient propagation efficiency. In addition, it can be seen that the electromagnetic waves propagated from the first waveguide 3B propagate with sufficient propagation efficiency through the second waveguide 5 from one end to the other end of the ridge 201. Note that although electromagnetic waves can be propagated in the same way without filling with the conductor 500, the propagation efficiency is better when filled. [Modification 5 of the First and Second Embodiments]

[0096] Next, Modification 5 of the first and second embodiments will be described. Figures 19A to 19C are drawings showing Modification 5. Figures 19A to 19C illustrate a configuration in which the configuration of Modification 5 is applied to waveguide device 1A, but Modification 5 is a configuration that can be applied to both the waveguide devices 1 and 1A of the first and second embodiments. Below, we will describe the case in which Modification 5 is applied to waveguide device 1A as a representative example.

[0097] As shown in FIGS. 19A and 19B , the waveguide surface 201S at one end of the ridge 201 is positioned opposite the lower end of the core conductor 300, the upper end of which is directly connected to the transmitting / receiving terminal 11 of the MMIC 10. Additionally, when viewed from the bottom side of the first member 102, the one end of the ridge 201 is surrounded by the SG terminal 12 and the shield ground terminal 13. The core conductor 300 may be configured as an IC pin via the IC pin or IC socket 14 of the second embodiment (see FIGS. 8A and 8B ). The surrounding SG terminal 12 and shield ground terminal 13 are each directly connected to the upper end of the peripheral conductor 103 that constitutes the first waveguide 3A. In the case of an IC pin configuration, the IC pin serving as the core conductor 300 can be disposed in the transmitting / receiving terminal 11 from the beginning of manufacturing. The SG terminal 12 and shield ground terminal 13 can be connected to the upper end of the peripheral conductor 103 by reflow soldering using solder ball terminals. The lower end of the peripheral conductor 103 is in contact with the first member 102 .

[0098] The lower end of the core conductor 300 is fixed to the upper surface (waveguide surface 201S) on one end side of the ridge 201 by soldering with a solder material 410. As the solder material 410, for example, a high-temperature solder material with a relatively high melting point, which is based on tin and contains silver, antimony, indium, etc., can be used. Here, although iron soldering can also be applied to the soldering with the solder material 410, in order to reduce the thermal load on other components due to high-temperature soldering and to shorten the soldering time, an example of a soldering method using a laser beam will be described below.

[0099] Specifically, as shown in FIG. 19C , a through-hole 204A for soldering is pre-formed in the WRG structure 4 at the soldering position on the top surface of the ridge 201, vertically penetrating the ridge 201 and the second member 200. The through-hole 204A has a diameter smaller than that of the core conductor 300. In other words, in the example of FIG. 19C , the lower end (lower power supply conductor) of the core conductor 300 is not inserted into the through-hole 204A. In the manufacturing process for high-temperature soldering, a laser beam LB is irradiated from the underside of the second member 200 through the through-hole 204A with pinpoint accuracy onto the solder material 410. This melts the solder material 410, allowing for soldering. This soldering method, for example, allows for non-contact soldering. This reduces the thermal load on other components due to pinpoint irradiation and shortens the physical operation time compared to contact-type soldering methods such as soldering irons. [Modification 6 of the First and Second Embodiments]

[0100] Next, Modification 6 of the first and second embodiments will be described. Figures 20 to 27B are drawings showing Modification 6. Figures 20 to 27B illustrate a configuration in which the configuration of Modification 6 is applied to the waveguide device 1 of the first embodiment, but Modification 6 is applicable to both the waveguide devices 1 and 1A of the first and second embodiments. Below, we will describe the case where Modification 6 is applied to the waveguide device 1 as a representative example. [Variation 6-1]

[0101] As shown in FIGS. 20(a) and 20(b), in the waveguide device 1 according to Modification 6-1, the upper end of the core conductor 310 is inserted into through holes provided in the substrate 100 and the first member 102, and the lower end is inserted into a through hole 204B provided in the WRG structure 4A in a non-contact manner while maintaining high-frequency coupling. Specifically, as shown in FIG. 21(a), the core conductor 310 according to Modification 6-1 has a cylindrical upper portion 310a with a height h1 and a cylindrical lower portion 310b with a height h2 that is larger in diameter and longer than the upper portion 310a. The lower portion 310b corresponds to the lower feed conductor 303 in FIG. 33. The upper portion 310a and the lower portion 310b are concentrically arranged. To cite a specific example of numerical values, the height h1 and diameter φa of the upper portion 310a can be, for example, 0.23 mm and 0.25 mm. In this case, the height h2 and diameter φb of the lower portion 310b may be, for example, 0.70 mm and 0.40 mm.

[0102] As shown in FIGS. 20(b) and 22, the WRG structure 4A according to Modification 6-1 has a through-hole 204B that vertically penetrates the ridge 201 and the second member 200 at a position on the waveguide surface 201S facing the lower end of the core conductor 310 at one end on the front side of the ridge 201. To give a specific example of numerical values, the diameter φc of the through-hole 204B can be, for example, 0.45 mm, corresponding to the above-mentioned numerical example. Furthermore, a thick portion 201t that protrudes upward and has a rectangular shape in top view is provided on the waveguide surface 201S adjacent to the rear side of the through-hole 204B of the ridge 201. This thick portion 201t forms a step on the waveguide surface 201S of the ridge 201. The thick portion 201t is provided to achieve a matching (impedance matching) state without reflection of electromagnetic waves at the connection portion between the first waveguide 3 and the second waveguide 5. 21(b) and 21(c) and 22, the upper portion 310a of the core conductor 310 is inserted into a through-hole provided in the substrate 100, and the upper end of the upper portion 310a, although not shown, is connected to the other end of the feed waveguide 302 by soldering, a conductive adhesive, or the like. In the case of a direct coupling configuration, it is directly connected to the transmitting / receiving terminal 11 of the MMIC 10.

[0103] Meanwhile, a portion of the lower portion 310b of the core conductor 310 is inserted from above into the portion of the through hole 204B on the ridge 201 side. At this time, the outer periphery of the inserted portion of the lower portion 310b is out of contact with the inner periphery of the through hole 204B and maintains a high-frequency coupled state. Specifically, the out-of-contact state occurs near the point where the difference between the outer diameter of the lower portion 310b and the inner diameter of the through hole 204B is approximately 0.5 mm. That is, there is a gap of 0.025 mm between the outer periphery of the lower portion 310b and the inner periphery of the through hole 204B. Furthermore, the portion of the through hole 204B below the lower portion 310b of the core conductor 310 is hollow.

[0104] In Modification 6-1, the inner diameter of the through hole 204B is less than half the wavelength λ of the propagating electromagnetic wave (millimeter wave). This prevents the electromagnetic wave from the first waveguide 3 from propagating below the lower portion 310b of the core conductor 310, thereby reducing transmission loss. Furthermore, the length h3 of the lower portion 310b of the core conductor 310 inserted into the through hole 204B can be set to a length that adjusts the connection between the first waveguide 3 and the second waveguide 5 to a matched state. As a result, as shown in FIGS. 23(a) to 23(d), it can be seen that the electromagnetic wave from the MMIC 10 propagates through the first waveguide 3 from above to below the substrate 100 with sufficient propagation efficiency. Additionally, it can be seen that the electromagnetic wave propagated from the first waveguide 3 propagates through the second waveguide 5 from one end of the ridge 201 to the other end with sufficient propagation efficiency. [Variation 6-2]

[0105] Next, a second configuration example of the high-frequency coupling according to Modification 6 will be described. Fig. 24 is a partial cross-sectional view showing the second configuration example of the high-frequency coupling according to Modification 6. This view is taken from the same perspective as the cross-sectional view taken along line A-A' in Fig. 20(a). Fig. 25 is a diagram showing simulation results of the transmission characteristics and reflection characteristics of the first waveguide 3 having the configuration shown in Fig. 24. In Fig. 25, the horizontal axis represents frequency (GHz) and the vertical axis represents transmission loss and return loss (dB).

[0106] As shown in FIG. 24, the waveguide device 1 according to Modification 6-2 has an elongated lower portion 310b of the core conductor 310. Specifically, the lower end of the lower portion 310b of the core conductor 310 inserted into the through hole 204B has a length that reaches the lower end of the through hole 204B. When the length of the through hole 204B is set to 1.325 mm, the S parameters of the first waveguide 3 are calculated using a circuit simulator, and the results are shown in FIG. 25. In this simulation, the characteristic impedance of the first waveguide 3 is set to 35 Ω. The relative permittivity of the substrate 100 is set to 3.0, and the dielectric loss angle tan δ of the dielectric is set to 0.003.

[0107] Here, the end of the first waveguide 3 on the upper surface side of the substrate 100 is designated as port 1, and the end of the second waveguide 5 opposite the end on the thick portion 201t side is designated as port 2. In this case, the S parameter S21 is the ratio (output power / input power) of the power of the electromagnetic wave input to port 1 to the power of the electromagnetic wave output from port 2. The larger this value (pass coefficient), the better the propagation characteristics can be said to be. However, in FIG. 25, the pass loss is converted into a negative dB value, and the smaller the absolute value of the numerical value, the smaller the loss.

[0108] The solid line in Figure 25 shows the simulation results for the transmission characteristics (S21). The simulation results, as shown by M11, M12, and M13 in the figure, yielded the following results at the target frequencies. Specifically, S21 (passage loss) was -1.158 dB at a frequency of 81 GHz, -1.093 dB at a frequency of 76 GHz, and -1.127 dB at a frequency of 79 GHz. Furthermore, the S-parameter S11 is the ratio (reflected power / input power) of the power of the electromagnetic wave input to port 1 to the power of the electromagnetic wave reflected by the load and returned to port 1. The smaller this value (reflection coefficient), the less reflection there is. However, in Figure 25, the return loss is converted to a negative dB value, and the larger the absolute value of the number, the less reflection there is.

[0109] Next, the dashed line in Figure 25 shows the simulation results for the reflection characteristics (S11). As shown in M08, M09, and M10 in the figure, the simulation results were as follows at the target frequencies: S11 (return loss) was -23.011 dB at a frequency of 81 GHz, -22.444 dB at a frequency of 76 GHz, and -22.407 dB at a frequency of 79 GHz.

[0110] The absolute values ​​of the insertion loss and return loss of this modification 6-2 are greater than those of the above modification 6-1 (not shown) at all frequencies of 81 GHz, 76 GHz, and 79 GHz. That is, when the insertion length of the lower portion 310b of the core conductor 310 into the through hole 204B is increased, the insertion loss increases while the reflection loss decreases. Therefore, it can be predicted that there is an optimal value for the insertion length. [Variation 6-3]

[0111] Next, a third configuration example of the high-frequency coupling according to Modification 6 will be described. Fig. 26A is a partial perspective view showing the third configuration example of the high-frequency coupling according to Modification 6. Fig. 26B(a) is a cross-sectional view taken along line A-A' in Fig. 26A, and Fig. 26B(b) is a partially enlarged view of Fig. 26B(a). Fig. 26C is a diagram showing simulation results of the transmission characteristics and reflection characteristics of the first waveguide 3 having the configuration shown in Fig. 26A. In Fig. 26C, the horizontal axis represents frequency (GHz), and the vertical axis represents transmission loss and return loss (dB).

[0112] 26A, the waveguide device 1 according to the modified example 6-3 includes a WRG structure 4B instead of the WRG structure 4A in the waveguide device 1 according to the modified example 6-1. Although not shown, the waveguide device 1 according to the modified example 6-3 has the upper end of the core conductor 310 inserted into the through holes provided in the substrate 100 and the first member 102, and connected to the feed waveguide 302, similar to the modified example 6-1.

[0113] 26A and 26B(a) and (b), the WRG structure 4B according to the modification 6-3 has a slit 204S that passes through the ridge 201 vertically to the conductive upper surface 200S of the second member 200, at the position of the waveguide surface 201S that faces the lower end of the core conductor 310 at one end on the front side of the ridge 201. In other words, the ridge 201 is divided into two at the position of the slit 204S.

[0114] The lower end of the lower portion 310b of the core conductor 310 according to Variation 6-3 is inserted into the slit 204S in a high-frequency coupled state, since it is close to but not in contact with the inner wall of the slit 204S. Similar to the WRG structure 4A of Variation 6-1, a thick portion 201t, which protrudes upward and has a rectangular shape in a top view, is provided on the waveguide surface 201S adjacent to the rear side of the slit 204S of the ridge 201. In this configuration, the S parameters of the first waveguide 3 were measured using a circuit simulator. In this simulation, the characteristic impedance of the first waveguide 3 was set to 35 Ω. The relative permittivity of the substrate 100 was set to 3.0, and the dielectric loss angle tanδ of the dielectric was set to 0.003. The end of the first waveguide 3 on the upper surface of the substrate 100 was designated port 1, and the end of the second waveguide 5 opposite the end on the thick portion 201t side was designated port 2.

[0115] 25 of Modification 6-2, the S parameter S21 is converted into a negative dB value as a passing loss, and the S parameter S11 is converted into a negative dB value as a return loss. Also, the solid line in Fig. 26C shows the simulation results of the passing characteristic (S21), and the dashed line in Fig. 26C shows the simulation results of the reflection characteristic (S11).

[0116] As shown by the solid line in FIG. 26C, the simulation result for S-parameter S21 was approximately 0 dB over the entire target frequency range of 77 to 81 GHz. Furthermore, as shown by the dashed line in FIG. 26C, the simulation result for S-parameter S11 was the smallest at approximately 79 GHz, at approximately 27 dB. Furthermore, the S-parameter S11 was approximately 17.5 dB at 77 GHz, which is the end of the target frequency range of 77 to 81 GHz, and approximately 18 dB at 81 GHz, gradually decreasing from both ends toward 79 GHz. From the above simulation results, even when slits 204S were used instead of through-holes 204B, good results were obtained for both the insertion loss and return loss over the target frequency range of 77 to 81 GHz. [Variation 6-4]

[0117] Next, a fourth configuration example of high-frequency coupling according to Modification 6 will be described. FIG. 27A is a partial cross-sectional view showing the fourth configuration example of high-frequency coupling according to Modification 6. As shown in FIG. 27A , a waveguide device 1 according to Modification 6-4 includes a core conductor 311 that is longer than the core conductor 300 of the first embodiment, instead of the core conductor 300 of the first embodiment. The core conductor 311 of Modification 6-4 has the configuration of a core extension conductor, similar to the core conductor 300 of the first embodiment. The WRG structure 4 according to Modification 6-4 has a recess 201c for inserting the lower end of the core conductor 311 on the waveguide surface 201S that faces the lower end of the core conductor 311 of the ridge 201. The lower end of the core conductor 311 is inserted into the recess 201c, and the outer periphery of the inserted portion is located near the inner periphery of the recess 201c and is close to, but not in contact with, the inner periphery, thereby achieving high-frequency coupling. With this configuration, similar to the above-described modified example 6-1, the electromagnetic wave propagated from the first waveguide 3 can be propagated to the second waveguide 5 with sufficient propagation efficiency. [Variation 6-5]

[0118] Next, a fifth configuration example of high-frequency coupling according to Modification 6 will be described. FIG. 27B is a partial cross-sectional view showing the fifth configuration example of high-frequency coupling according to Modification 6. As shown in FIG. 27B, in the waveguide device 1 according to Modification 6-5, the inner periphery of the through hole 204 and the outer periphery of the lower feed conductor 307 are in close proximity but not in contact with each other in the waveguide device 1 according to Modification 2-5 shown in FIG. 15C , and thus a high-frequency coupling state is achieved. Specifically, the outer diameter of the lower feed conductor 307 according to Modification 6-5 is configured to be smaller than the inner diameter of the through hole 204, and the inserted portion of the lower feed conductor 307 into the through hole 204 is in close proximity but not in contact with the inner periphery of the through hole 204, thereby achieving a high-frequency coupling state. For example, the distance between the outer periphery of the lower feed conductor 307 and the inner periphery of the through hole 204 is approximately 0.1 mm. With this configuration, similar to the above-described modified example 6-2, the electromagnetic wave propagated from the first waveguide 3 can be propagated to the second waveguide 5 with sufficient propagation efficiency. [Seventh Modification of the First and Second Embodiments]

[0119] Next, Modification 7 of the first and second embodiments will be described. Fig. 28A is a cross-sectional view showing a schematic configuration example of a waveguide device 1B according to Modification 7. Note that Fig. 28A illustrates a configuration in which the configuration of Modification 7 is applied to the waveguide device 1 of the first embodiment, but Modification 7 is a configuration that can be applied to both the waveguide devices 1 and 1A of the first and second embodiments. Below, a case in which it is applied to the waveguide device 1 will be described as a representative.

[0120] As shown in FIG. 28A , the waveguide device 1B has a configuration in which the WRG structure 4 in the waveguide device 1 of the first embodiment is replaced with a WRG structure 4C. The WRG structure 4C includes a rod-shaped conductor 202A provided on the conductive upper surface 200S of the second member 200, at a position forward beyond a ridge front end face 201a, which is the front end face of the ridge 201, and facing the ridge front end face 201a. Furthermore, the WRG structure 4C includes a rod-shaped conductor 202B provided on the conductive upper surface 200S of the second member 200, at a position rearward beyond a ridge rear end face 201b, which is the rear end face of the ridge 201, and facing the ridge rear end face 201b. Specifically, the rod-shaped conductor 202B is provided at a position facing the ridge rear end face 201b in the X direction, with the opening 203 sandwiched therebetween.

[0121] The rod-shaped conductors 202A and 202B are made of rod-shaped conductors and are configured so that their upper surfaces are positioned at the same height as the waveguide surface 201S of the ridge 201. In other words, the upper surfaces of the rod-shaped conductors 202A and 202B are adjacent to the waveguide surface 201S of the ridge 201. The rod-shaped conductors 202A and 202B may be made entirely of a conductor, or may be configured such that a conductive surface is provided on the surface of a rod-shaped dielectric, for example.

[0122] In the example shown in FIG. 28A , the number of rod-shaped conductors 202A and 202B on the front and rear sides of the ridge 201 is two, but this configuration is not limited thereto. Alternatively, one rod-shaped conductor or three or more rod-shaped conductors may be provided. With this configuration, the rod-shaped conductors 202A and 202B form an artificial magnetic wall, which prevents electromagnetic waves propagating through the first waveguide 3 from traveling from the front end of the ridge 201 to the space outside the front. In addition, it prevents electromagnetic waves propagating rearward through the second waveguide 5 from traveling beyond the opening 203 to the space beyond. In other words, the rod-shaped conductors 202A and 202B can restrict the path of the electromagnetic waves so that they propagate along a desired path. In this seventh modification, the rod-shaped conductor 202A on the front side of the ridge 201 corresponds to the first rod-shaped conductor, and the rod-shaped conductor 202B on the rear side of the ridge 201 corresponds to the second rod-shaped conductor. [Variation 8 of the First and Second Embodiments]

[0123] Next, an eighth modification of the first and second embodiments will be described. Fig. 28B is a cross-sectional view showing a schematic configuration example of a waveguide device 1C according to this eighth modification. Note that Fig. 28B illustrates a configuration in which the configuration of this eighth modification is applied to the waveguide device 1 of the first embodiment, but this eighth modification is applicable to both the waveguide devices 1 and 1A of the first and second embodiments. Below, a case in which it is applied to the waveguide device 1 will be described as a representative.

[0124] As shown in FIG. 28B , the waveguide device 1C includes a WRG structure 4D instead of the WRG structure 4 in the waveguide device 1 of the first embodiment. The WRG structure 4D includes, in place of both the rod-shaped conductor 202A on the front side of the ridge 201 and the rod-shaped conductor 202B on the rear side, rod-shaped conductors 202C and 202D, respectively, which are extended to a height such that their upper ends contact the conductive lower surface 102S of the first member 102. In the example shown in FIG. 28B , there are two rod-shaped conductors 202C and two rod-shaped conductors 202D on the front side and the rear side of the ridge 201, respectively. However, this configuration is not limited thereto, and one rod-shaped conductor each, or three or more rod-shaped conductors each, may be provided. With this configuration, the side surfaces of the rod-shaped conductors 202C and 202D facing the ridge front end surface 201a and the ridge rear end surface 201b form electric walls, respectively. This prevents electromagnetic waves propagating through the first waveguide 3 from traveling from the front end of the ridge 201 into the space outside the front. In addition, it is possible to prevent electromagnetic waves propagating rearward through the second waveguide 5 from traveling beyond the opening 203 into the space beyond the opening 203. That is, the rod-shaped conductors 202C and 202D on the front and rear sides of the ridge 201 can restrict the path of the electromagnetic waves so that they propagate along a desired path. In this eighth modification, the rod-shaped conductor 202C on the front side of the ridge 201 corresponds to the first rod-shaped conductor, and the rod-shaped conductor 202D on the rear side of the ridge 201 corresponds to the second rod-shaped conductor. [Modification 9 of the First and Second Embodiments] Next, a ninth modification of the first and second embodiments will be described. Fig. 28C is a top view of a WRG structure 4E according to this ninth modification. Fig. 28D is a cross-sectional view of a waveguide device 1D according to this ninth modification taken along line A-A' in Fig. 28C.

[0125] 28C and 28D, the waveguide device 1D includes a WRG structure 4E instead of the WRG structure 4 in the waveguide device 1 of the first embodiment. The WRG structure 4E includes wall portions 202E and 202F, which are obtained by expanding the widths of the rod-shaped conductors 202C on the front side of the ridge 201 and the rod-shaped conductors 202D on the rear side of the ridge 201 in the WRG structure 4D of the eighth modification, respectively, in the front-rear direction (X direction) and the left-right direction (Y direction).

[0126] In the example shown in FIGS. 28C and 28D, the width of the ridge 201 in the left-right direction is set to λo / 8. Here, λo is the free-space wavelength of the electromagnetic wave at the center frequency of the operating frequency band of the waveguide device 1D. Additionally, in the example shown in FIGS. 28C and 28D, the width of the walls 202E and 202F in the left-right direction is set to λo / 4 or more. This configuration allows the side surfaces of the walls 202E and 202F facing the ridge front end face 201a and the ridge rear end face 201b to form electric walls, respectively. This prevents electromagnetic waves propagating through the first waveguide 3 from traveling from the front end of the ridge 201 to the space outside the front. Additionally, it prevents electromagnetic waves propagating backward through the second waveguide 5 from traveling beyond the opening 203 to the space beyond. That is, the path of the electromagnetic wave can be restricted so that it propagates along a desired path by the wall portions 202E and 202F on the front and rear sides of the ridge 201. In this ninth modification, the wall portion 202E on the front side of the ridge 201 corresponds to a first rod-shaped conductor having a width of λo / 4 or more, and the wall portion 202F on the rear side of the ridge 201 corresponds to a second rod-shaped conductor having a width of λo / 4 or more. [Modification 10 of the First and Second Embodiments]

[0127] Next, a tenth modification of the first and second embodiments will be described. Fig. 29A is a side cross-sectional view showing a schematic configuration example of a waveguide device 1E according to a first configuration example of the tenth modification. Fig. 29B is a side cross-sectional view showing a schematic configuration example of a waveguide device 1F according to a second configuration example of the tenth modification. Fig. 29C is a side cross-sectional view showing a schematic configuration example of a waveguide device 1G according to a third configuration example of the tenth modification. [Variation 10-1]

[0128] 29A , a waveguide device 1E according to a first configuration example has a configuration in which, in the waveguide device 1 according to the first embodiment, the lower end of a core conductor 300 having the configuration of a core extension conductor is in contact with the center position in the front-to-rear direction of the waveguide surface 201S of the ridge 201. With this configuration, the electromagnetic waves propagated from the first waveguide 3 can be branched into two directions, forward and backward, at the center in the front-to-rear direction of the waveguide surface 201S of the ridge 201 that constitutes the second waveguide 5. In other words, power can be fed evenly forward and backward.

[0129] Next, we will explain the results of simulating the transmission loss and return loss of the first waveguide 3 and the second waveguide 5 according to the first structural example of the ninth modified example. FIG. 29D shows the results of simulating the transmission and reflection characteristics of the first waveguide 3 and the second waveguide 5 of the waveguide device 1E. Note that in FIG. 29D, the solid line graphs corresponding to S31 and S32 only show the results for S31, but similar results were obtained for S32. Here, the front end of the second waveguide 5 is designated as port 1, the rear end as port 2, and the end of the first waveguide 3 on the upper surface side of the substrate 100 as port 3. Therefore, S31 is the ratio of the power of the electromagnetic wave input to port 1 to the power of the electromagnetic wave output from port 3. Furthermore, S32 is the ratio of the power of the electromagnetic wave input to port 2 to the power of the electromagnetic wave output from port 3. Furthermore, S33 is the ratio of the power of the electromagnetic wave input to port 3 to the power of the electromagnetic wave reflected by the load and returning. In FIG. 29D, S31, S32, and S33 are converted into negative dB values ​​as the insertion loss and return loss.

[0130] The solid line in FIG. 29D shows the simulation results of the transmission characteristics (passage loss), where both S31 and S32 were approximately -3 dB in the target frequency range of 70 to 88 GHz. The dashed line in FIG. 29D shows the simulation results of the reflection characteristics (return loss), where the return loss was as follows at the target frequency: S33 (return loss) was less than -40 dB at frequencies between 78 and 79 GHz, approximately -17 dB at 70 GHz, and a maximum of approximately -16 dB at 88 GHz, decreasing from 70 GHz and 88 GHz to 78 to 79 GHz. From these simulation results, it can be seen that S31 and S32 were both -3 dB, indicating that electromagnetic wave power supply was uniform. Furthermore, S33 also showed favorable results, with low return loss in the target frequency band. [Variation 10-2]

[0131] 29B , in the waveguide device 1F according to the second configuration example, the lower end of a core conductor 300 having the configuration of a core extension conductor in the waveguide device 1A according to the second embodiment is brought into contact with the center position in the front-to-rear direction of the waveguide surface 201S of the ridge 201. With this configuration, the electromagnetic waves propagated from the first waveguide 3A can be branched into two directions, forward and backward, at the center in the front-to-rear direction of the waveguide surface 201S of the ridge 201 that constitutes the second waveguide 5. In other words, power can be supplied evenly to the front and rear. [Variation 10-3]

[0132] 29C is a configuration in which the configuration of Modification 10-3 is applied to the waveguide device 1 of the first embodiment, but Modification 10-3 is a configuration that can be applied to both the waveguide devices 1 and 1A of the first and second embodiments. Below, we will explain the case in which it is applied to the waveguide device 1 as a representative example.

[0133] As shown in FIG. 29C , the waveguide device 1G according to the third configuration example has a configuration in which the lower end of a core conductor 311, which is an extension of the core conductor 300 having the configuration of a core extension conductor in the waveguide device 1 according to the first embodiment, is inserted into a recess 201c provided at the center of the waveguide surface 201S of the ridge 201 in the front-to-rear direction. Specifically, the waveguide device 1G has a configuration in which Modification 6-4 of the first embodiment is applied to the waveguide device 1. That is, the outer periphery of the lower end of the core conductor 311 is in close proximity to, but not in contact with, the inner periphery of the recess 201c, thereby achieving high-frequency coupling. With this configuration, as with Modification 10-1, electromagnetic waves propagating from the first waveguide 3 can be branched into two directions, forward and backward, at the center of the waveguide surface 201S of the ridge 201 that constitutes the second waveguide 5 in the front-to-rear direction. That is, power can be supplied evenly forward and backward.

[0134] Next, we will explain the results of simulations of the transmission loss and return loss of the first waveguide 3 and the second waveguide 5 according to the above-described Modification 10-3. Figure 29E shows the simulation results of the transmission and reflection characteristics of the first waveguide 3 and the second waveguide 5 of the waveguide device 1G. In Figure 29E, the solid line graphs corresponding to S31 and S32 only show the results for S31, but similar results were obtained for S32. Here, the front end of the second waveguide 5 is designated port 1, the rear end is designated port 2, and the end of the first waveguide 3 on the upper surface side of the substrate 100 is designated port 3. In Figure 29E, S31, S32, and S33 are converted into negative dB values ​​as the transmission loss and return loss. The solid lines in Figure 29E show the simulation results of the transmission characteristics (passage loss). The transmission loss for both S31 and S32 was approximately -3 dB in the target frequency range of 70 to 88 GHz. The dashed line in Figure 29E shows the simulation results of the reflection characteristics (return loss), and the return loss results were as follows at the target frequencies: S33 (return loss) was approximately -32.5 dB at a frequency of 78 GHz and reached a minimum of approximately -34 dB at approximately 78.5 GHz; it was approximately -16 dB at 70 GHz and a maximum of approximately -14 dB at 88 GHz, decreasing from 70 GHz and 88 GHz to 78.5 GHz. From these simulation results, it can be seen that S31 and S32 were both approximately -3 dB, indicating that electromagnetic wave power supply was approximately uniform. Furthermore, S33 also showed low return loss in the target frequency band, resulting in favorable results. [Modification 11 of the First and Second Embodiments]

[0135] Next, an eleventh modification of the first and second embodiments will be described. Figures 30(a) to 30(d) are schematic diagrams showing another structural example of impedance matching using a thickness-changing portion of the ridge 201 according to the eleventh modification. Figures 30(a) to 30(d) correspond to the two-way power feeding configuration of the tenth modification. [First structure example]

[0136] In a first structural example of Modification 11, as shown in FIG. 30( a), the matching structure of Modification 11 is applied to a configuration in which the lower end of the core conductor 300 is in contact with the center position of the waveguide surface 201S of the ridge 201 in the front-to-rear direction. In the first structural example, as shown in FIG. 30( a), thick portions 201t are provided on the waveguide surface 201S of the ridge 201, protruding upward, at positions close to the front and rear of the lower end of the core conductor 300. Here, "close" means that the uneven portion or the portion with a varying thickness is within a distance range that affects the matching conditions for electromagnetic wave propagation between the first waveguide 3 and the second waveguide 5. In addition, thick portions 201st are provided on the left and right side surfaces of the front and rear of the ridge 201, protruding left and right, respectively, at positions close to the left and right of the lower end of the core conductor 300. With this configuration, stepped portions (uneven portions) due to the thick portions 201t are formed on the top surface of the ridge 201 at positions close in both the front-rear direction to the lower end of the core conductor 300. Furthermore, stepped portions (uneven portions) due to the thick portions 201st are formed on the left and right side surfaces of the ridge 201 at positions close in both the left-right direction to the lower end of the core conductor 300. As a result, the thick portions 201t on the top surface and the thick portions 201st on the side surfaces can match (impedance match) the waveguide connections with the two-way feed paths of the first waveguide 3 and the second waveguide 5. [Second structure example]

[0137] In a second structural example of Modification 11, as shown in FIG. 30(b), the matching structure of Modification 11 is inserted in a high-frequency coupled state by placing the lower end of the core conductor 300 in a recess 201c provided at the center of the waveguide surface 201S of the ridge 201 in the front-to-rear direction, but in close proximity to the recess 201c. As shown in FIG. 30(b), the second structural example, like the first structural example, has thick portions 201t provided on the top surface of the ridge 201 in positions close to the lower end of the core conductor 300 in both the front-to-rear direction. In addition, thick portions 201st are provided on the side surfaces of the ridge 201 in positions close to the lower end of the core conductor 300 in both the left-to-right direction in a top view. This allows the thick portions 201t on the top surface and the thick portions 201st on the side surfaces to match (impedance match) the waveguide connections with the two-way feed paths of the first waveguide 3 and the second waveguide 5. In the second structural example, the outer periphery of the lower end of the core conductor 300 may be in contact with the inner periphery of the recess 201c. [Third structure example]

[0138] 30(c), a third structural example of Modification 11 is configured such that the lower end of the core conductor 300 is inserted into a through-hole 204 provided at the center of the waveguide surface 201S of the ridge 201 in the front-to-rear direction, in a high-frequency coupled state, while being in close proximity to the through-hole 204 but not in contact with the matching structure of Modification 11. Similar to the first structural example, as shown in FIG. 30(c), the third structural example has thick portions 201t provided on the top surface of the ridge 201 at positions close to the lower end of the core conductor 300 in both the front-to-rear direction. In addition, thick portions 201st are provided on the side surfaces of the ridge 201 at positions close to the lower end of the core conductor 300 in both the left-to-right direction in a top view. This allows the thick portions 201t on the top surface and the thick portions 201st on the side surfaces to match (impedance match) the connections between the first waveguide 3 and the second waveguide 5 and the feed paths in two directions. In the third structural example, the outer periphery of the lower end of the core conductor 300 and the inner periphery of the through hole 204 may be in contact with each other. [Fourth structure example]

[0139] In a fourth structural example of the eleventh modification, as shown in FIG. 30(d), the matching structure of the eleventh modification is arranged such that the lower end of the core conductor 300 is in close proximity to, but not in contact with, a slit 204S provided at the center of the waveguide surface 201S of the ridge 201 in the X direction, thereby providing a high-frequency coupling state. As shown in FIG. 30(d), in the fourth structural example, thick portions 201t are provided protruding upward at positions close to the lower end of the core conductor 300 on the waveguide surface 201S of the ridge 201 in the front-rear direction, with the slit 204S sandwiched between them. In addition, thick portions 201st are provided protruding left and right at positions close to the thick portions 201t on the left and right side surfaces of the front end of the ridge 201, with the slit 204S sandwiched between them. Furthermore, thick portions 201st are provided protruding left and right at positions close to the thick portions 201t on the left and right side surfaces of the rear end of the ridge 201, with the slit 204S sandwiched between them. Furthermore, a front-rear direction connecting portion 201ct is provided at a position close to the lower end of the core conductor 300 inside the slit 204S so as to connect both end faces facing each other inside the slit 204S.

[0140] With this configuration, stepped portions (uneven portions) due to the thick portions 201t are formed on the top surface of the ridge 201 at positions close in both the front-rear direction to the lower end of the core conductor 300. Furthermore, stepped portions (uneven portions) due to the thick portions 201st are formed on the left and right side surfaces of the ridge 201 at positions close in both the front-rear direction to the lower end of the core conductor 300 at both ends of the front-rear direction across the slit 204S. Furthermore, a front-rear direction connecting portion 201ct is formed on the inside of the slit 204S at a position close to and below the lower end of the core conductor 300. As a result, the thick portions 201t on the top surface, the thick portions 201st on the left and right side surfaces, and the front-rear direction connecting portion 201ct enable matching (impedance matching) of the connections between the first waveguide 3 and the second waveguide 5 and the power feed paths in two directions. In the fourth structural example, the outer periphery of the lower end of the core conductor 300 may be in contact with both inner ends of the slit 204S. [Details of the waffle iron structure]

[0141] Next, the waffle iron structure of the WRG structure will be described in more detail with reference to FIG. 3(c). As shown in FIG. 3(c), the rods 202 arranged on the second member 200 each have a tip 202a facing the conductive lower surface 102S. In the illustrated example, the tip 202a of the rods 202 are coplanar. This plane forms the surface 202c of the artificial magnetic conductor. Each rod 202 does not need to be conductive throughout; it is sufficient that a conductive layer extends along at least the top and side surfaces of the rod-shaped structure. This conductive layer may be located on the surface of the rod-shaped structure, but the surface layer may be made of an insulating coating or resin layer, and no conductive layer may be present on the surface of the rod-shaped structure. Furthermore, the second member 200 does not need to be conductive throughout as long as it can support the rods 202 and realize the artificial magnetic conductor.

[0142] It is sufficient that the conductive upper surface 200S, which is the surface of the second member 200 on which the plurality of rods 202 are arranged, is conductive, and the surfaces of the adjacent plurality of rods 202 are electrically connected by a conductor. The conductive layer of the second member 200 may be covered with an insulating coating or a resin layer. In other words, it is sufficient that the entire combination of the second member 200 and the plurality of rods 202 has an uneven conductive layer facing the conductive lower surface 102S of the first member 102.

[0143] The space between the surface 202c of each artificial magnetic conductor and the conductive lower surface 102S of the first member 102 does not allow electromagnetic waves having frequencies within a specific frequency band to propagate. Such a frequency band is called a "forbidden band." The artificial magnetic conductor is designed so that the frequency of the electromagnetic waves propagating within the waveguide device 1 (hereinafter sometimes referred to as the "operating frequency") is included in the forbidden band. The forbidden band can be adjusted by the height of the rods 202, i.e., the depth of the grooves formed between adjacent rods 202, the width and spacing of the rods 202, and the size of the gap between the tip 202a of the rod 202 and the conductive lower surface 102S.

[0144] The waveguide device is used for at least one of transmitting and receiving electromagnetic waves in a predetermined band (hereinafter referred to as the "operating frequency band"). The free-space wavelength of electromagnetic waves with a center frequency in the operating frequency band of the waveguide device is denoted as λo. The end of each rod 202 that contacts the second member 200 is referred to as the "base." Each rod 202 has a tip 202a and a base 202b. Examples of the dimensions, shape, and arrangement of each member are as follows. For example, as shown in FIG. 3(c), the width (size in the X and Y directions) of the rod 202 can be set to less than λo / 2. Within this range, the occurrence of lowest-order resonance in the X and Y directions can be prevented. Note that resonance may occur not only in the X and Y directions but also in the diagonal directions of the XY cross section. Therefore, it is preferable that the length of the diagonal line of the XY cross section of the rod 202 is also less than λo / 2. Furthermore, the distance from the base 202b of the rod 202 to the conductive lower surface 102S of the first member 102 can be set to be longer than the height of the rod 202 and less than λo / 2. If this distance is λo / 2 or more, resonance occurs between the base 202b of the rod 202 and the conductive lower surface 102S, and the electromagnetic wave confinement effect is lost.

[0145] Furthermore, the distance L from the tip 202a of each rod 202 to the conductive lower surface 102S is set to be less than λo / 2. This is because if this distance is greater than λo / 2, a propagation mode occurs in which electromagnetic waves travel back and forth between the tip 124a of each rod 202 and the conductive lower surface 102S, making it impossible to confine the electromagnetic waves. The tip 202a of each of the multiple rods 202 is not in electrical contact with the conductive lower surface 102S. Here, the state in which the tip 202a of each rod 202 is not in electrical contact with the conductive lower surface 102S refers to either a state in which there is a gap between the tip 202a and the conductive lower surface 102S, or a state in which an insulating layer exists on either the tip 202a or the conductive lower surface 102S, and the tip 202a of each rod 202 is in contact with the conductive lower surface 102S via the insulating layer. In order to ensure ease of manufacture, when propagating electromagnetic waves in the millimeter wave band, the distance L can be set to, for example, λo / 16 or more.

[0146] Furthermore, the gap between two adjacent rods 202 among the multiple rods 202 has a width of, for example, less than λo / 2. The width of the gap between two adjacent rods 202 is defined by the shortest distance from one surface (side surface) of the two rods 202 to the other surface (side surface) of the two rods 202. The width of this gap between the rods is determined so that the lowest-order resonance does not occur in the region between the rods. The conditions for resonance are determined by a combination of the height of the rods 202, the distance between the two adjacent rods, and the capacitance of the gap between the tip end 202a of the rod 202 and the conductive lower surface 102S. Therefore, the width of the gap between the rods is determined appropriately depending on other design parameters. There is no clear lower limit to the width of the gap between the rods, but to ensure ease of manufacturing, it may be, for example, λo / 16 or more when propagating millimeter-wave electromagnetic waves. Note that the width of the gap does not need to be constant. The gap between the rods 202 may have various widths as long as it is less than λo / 2.

[0147] Furthermore, the arrangement of the multiple rods 202 is not limited to the illustrated example, as long as it functions as an artificial magnetic conductor. The multiple rods 202 do not need to be arranged in orthogonal rows and columns; the rows and columns may intersect at angles other than 90 degrees. The multiple rods 202 do not need to be arranged in a straight line along the rows or columns; they may be distributed without any simple regularity. The shape and size of each rod 202 may also vary depending on its position on the second member 200. Furthermore, the surface 124c of the artificial magnetic conductor formed by the tips 202a of the multiple rods 202 does not need to be strictly flat; it may be a flat or curved surface with minute irregularities. In other words, the height of each rod 202 does not need to be uniform; individual rods 202 may have diversity within the range in which the arrangement of the rods 202 functions as an artificial magnetic conductor.

[0148] Each rod 202 is not limited to the illustrated rectangular column shape and may have, for example, a cylindrical shape. Furthermore, each rod 202 does not need to have a simple columnar shape. An artificial magnetic conductor can be realized by structures other than an array of rods 202, and various artificial magnetic conductors can be used in the waveguide device of the present disclosure. When the tip 202a of each rod 202 is rectangular column-shaped, the length of its diagonal is preferably less than λo / 2. When the tip 202a is elliptical, the length of its major axis is preferably less than λo / 2. Even if the tip 202a has another shape, the diameter of the tip 202a is preferably less than λo / 2 at its longest point. The height of the rod 202, i.e., the length from the base 202b to the tip 202a, can be set to a value shorter than the distance (less than λo / 2) between the conductive lower surface 102S and the conductive upper surface 200S, for example, λo / 4.

[0149] 3(c), conductive upper surface 200S is planar, but the embodiment of the present disclosure is not limited thereto. For example, conductive upper surface 200S may be the bottom of a surface whose cross section parallel to the XZ plane is shaped like a U or V. Conductive upper surface 200S has such a structure when rod 202 has a shape (tapered shape) in which the width increases from tip 202a to base 202b. Even with such a structure, the illustrated device can function as a waveguide device according to the embodiment of the present disclosure as long as the distance between conductive lower surface 102S and conductive upper surface 200S is shorter than half the wavelength λo. [Other structural examples of the electromagnetic wave shielding wall 210] Next, a description will be given of another structural example of the electromagnetic wave shielding wall 210. Figures 31A and 31B are diagrams showing another structural example of the electromagnetic wave shielding wall 210.

[0150] 31A(a), (b), and (c) are partial cross-sectional views showing first, second, and third structural examples of the electromagnetic wave shielding wall 210. FIGS. 31A(d), (e), and (f) are partial top views of the waveguide devices having the structures of FIGS. 31A(a), (b), and (c), seen from the position cut along line CC'. FIG. 31B(a) is a partial cross-sectional view showing a fourth structural example of the electromagnetic wave shielding wall 210. FIG. 31B(b) is a partial top view of the waveguide device having the structure of FIG. 31B(a), seen from the position cut along line CC'. [First structure example]

[0151] A first structural example of the electromagnetic wave shielding wall 210 is the structure disclosed in the above-described embodiment and its modified examples, as shown in Figures 31A(a) and (d). However, the space 206 between the first member 102 and the second member 200 is filled with a gas other than air, a vacuum, or a dielectric. In either case, an artificial magnetic conductor is formed by the row of rods 202 adjacent to the ridge 201, and an artificial magnetic wall is formed as the electromagnetic wave shielding wall 210. This makes it possible to confine electromagnetic waves in the operating frequency band. [Second structure example]

[0152] 31A(b) and (e), the second structural example of the electromagnetic wave shielding wall 210 includes, as a member corresponding to the ridge, a line 213 formed in a wiring layer in a dielectric layer filling the space 206 between the first member 102 and the second member 200. Specifically, a strip-shaped line 213 having a strip-shaped waveguide surface on at least the upper surface thereof is formed in the wiring layer. The configuration of the other components such as the rod 202 is similar to that of the first structural example. With this configuration, an artificial magnetic conductor is formed by the row of rods 202 adjacent to the line 213, and an artificial magnetic wall is formed as the electromagnetic wave blocking wall 210. This makes it possible to confine electromagnetic waves in the operating frequency band. The space 206 is not limited to being entirely filled with a dielectric material, and for example, the portion above the wiring layer may be filled with air, gas, or vacuum instead of a dielectric material. [Third structure example]

[0153] 31A(c) and (f), the third structural example of the electromagnetic wave shielding wall 210 includes a ridge 213 composed of a dielectric support portion 213a and a conductive line 213b formed on the support portion 213a. Specifically, the support portion 213a is provided on the conductive upper surface 200S of the second member 200, and has a strip-shaped upper surface extending along the X direction. The line 213b is provided in a strip shape on the upper surface of the support portion 213a, and has a waveguide surface that is the conductive upper surface. Other configurations are similar to those of Structural Example 1. The space 206 is filled with air, gas, vacuum, or the like. With this configuration, an artificial magnetic conductor is formed by the row of rods 202 adjacent to the ridge, and an artificial magnetic wall is formed as the electromagnetic wave blocking wall 210. This makes it possible to confine electromagnetic waves in the operating frequency band. [Fourth structure example]

[0154] 31B(a) and (b), the fourth structural example of the electromagnetic wave shielding wall 210 is configured with a post 212 instead of the rod 202 of the first to third structural examples. The post 212 is configured from the same material and has the same shape as the rod 202. However, the post 212 differs from the rod 202 in that the upper end of the post 212 is in contact with the conductive lower surface 102S of the first member 102 and the lower end of the post 212 is in contact with the conductive upper surface 200S of the second member 200.

[0155] 31B(a), post 212 is formed integrally with second member 200 as part of second member 200, protrudes upward from conductive upper surface 200S, and its upper end contacts conductive lower surface 102S of first member 102. At least the side surface of post 212 is conductive, and is electrically connected to, for example, conductive lower surface 102S of first member 102 and conductive upper surface 200S of second member 200.

[0156] The upper edge of the side surface of the post 212 preferably contacts the conductive lower surface 102S of the first member 102 and is electrically conductive with the conductive lower surface 102S. Alternatively, if the upper surface of the post 212 is conductive and continuous with the side surface, it is preferable that at least a portion of the upper surface of the post 212 contacts the conductive lower surface 102S of the first member 102 and is electrically conductive with the conductive lower surface 102S. Note that in the fourth structural example, the upper surface of the post 212 and the conductive lower surface 102S abut or are in close contact with each other, but they may also be connected. Here, "joined" refers to a state in which the post 212 is part of the first member 102 or is fixed integrally thereto by diffusion bonding, caulking, screwing, or the like. Furthermore, a structure in which a conductive member, such as a conductive adhesive, conductive oil, conductive rubber, or elastic conductive resin, is interposed between the upper surface of the post 212 and the conductive lower surface 102S may be used. The upper surface of post 212 and conductive lower surface 102S may have a small gap therebetween or may be electrically separated by a thin non-conductive film. In this case, post 212 can still provide the effect of suppressing electromagnetic wave leakage, but the effect is weaker than when the side surface of post 212 is electrically connected to conductive lower surface 102S. Even in this configuration, the space 206 may be filled with air, gas, vacuum, or the like, or may be partially or entirely filled with a dielectric material. With this configuration, the side surfaces of the posts 212 facing the ridge 201 are conductive, and the row of posts 212 adjacent to the ridge 201 forms an electric wall as an electromagnetic wave blocking wall 210. This makes it possible to confine electromagnetic waves in the operating frequency band. The post 212 is not limited to a columnar shape, and may be formed of, for example, a wall-like structure extending along the longitudinal direction of the ridge 201. [Application example to radar equipment]

[0157] Next, a radar device including a waveguide device according to an embodiment of the present disclosure will be described with reference to FIG. 32. FIG. 32 is a cross-sectional view showing a schematic configuration example of a radar device 600. The example of FIG. 32 employs the waveguide device 1B according to the seventh modification, but waveguide devices according to other embodiments and modifications may also be employed. As shown in FIG. 32, the radar device 600 includes the waveguide device 1B and an antenna member 250. The antenna member 250 includes a third member 260 formed of a plate-shaped conductive member and a horn radiation hole 270 extending vertically through the third member 260. The antenna member 250 is provided on the lower surface side of the second member 200, and is positioned so that the horn radiation hole 270 is located directly below the opening 203 of the WRG structure 4C of the waveguide device 1B. The number of horn radiation holes 270 corresponds to the number of ridges 201 of the waveguide device 1B. With this configuration, the opening 203 of the WRG structure 4C functions as a waveguide, and electromagnetic waves can be propagated between the second waveguide 5 and the horn radiation hole 270.

[0158] While FIG. 32 illustrates an example in which there is one set of aperture 203 and horn radiation hole 270, this configuration is not limiting. For example, multiple apertures 203 corresponding to each ridge 201 may be provided in the WRG structure 4C, and multiple horn radiation holes 270 corresponding to each ridge 201 may be provided in the third member 260 of the antenna member 250. Alternatively, a new ridge waveguide layer (not shown) may be provided below the aperture 203, and horn radiation holes or slit radiation holes may be disposed at the end of the ridge waveguide. This allows for the configuration of a radar device equipped with an array antenna. The radar device 600 also includes a radar calculation unit (not shown) that calculates the position and relative velocity information of a detection target based on the transmitted and received electromagnetic waves. As described above, the radar device 600 can transmit electromagnetic waves to the outside through the horn radiation hole 270 and receive electromagnetic waves reflected from the target. This allows the radar device to function as a radar device. [Basic configuration diagram]

[0159] FIG. 33 schematically illustrates the basic structure of a waveguide device 1 according to the present invention. As shown in FIG. 33, in the waveguide device 1, a high-frequency circuit 10 having a transmitting or receiving terminal 11 and a signal ground terminal 12 is disposed on the upper surface or on the upper side of a substrate 100. A first member 102 having a conductive lower surface electrically connected to the signal ground terminal 12 of the high-frequency circuit 10 is disposed along the lower surface or on the lower side of the substrate 100. A second member 200 having a conductive upper surface is disposed along the lower surface of the first member 102. In the waveguide device 1, a ridge 201 having a strip-shaped conductive upper surface is disposed on the upper surface or on the upper side of the second member 200. Although not shown, a plurality of rods (e.g., rods 202 in FIG. 3) serving as electromagnetic wave shielding walls are disposed on both sides of the ridge 201 in the extending direction. A second waveguide 5 is formed between the conductive upper surface of the ridge 201 and the lower surface of the first member 102.

[0160] The substrate 100 has a first waveguide 3 penetrating in the vertical direction, which is composed of a core conductor 300 and a peripheral conductor 103. An upper feed part 302 is arranged on the substrate 100 between the terminal 11 for transmitting or receiving and the upper end of the core conductor 300, and they are connected to each other at the electromagnetic wave level. The lower end of the core conductor 300 contacts the upper end of a lower feed conductor 303 extending below the substrate, and the lower end of the lower feed conductor 303 contacts or is high-frequency coupled to the conductive upper surface of the ridge 201. [Explanation of symbols]

[0161] 1, 1A to 1G... Waveguide device, 2, 2A... IC mounting substrate, 3, 3A to 3B... First waveguide, 4, 4A to 4D... WRG structure portion, 5... Second waveguide, 10... Millimeter-wave IC (MMIC), 11... Transmitting / receiving terminal, 12... SG terminal, 13... Shield ground terminal, 14... IC socket, 15... Transmitter portion, 100... Substrate, 101... Ground, 102... First member, 102S... Conductive lower surface, 103... Peripheral conductor, 104... Through hole, 105... Through via hole, 200... Second member, 200S... Conductive upper surface, 201... Ridge, 201a... Ridge front end face, 201b... Ridge rear 201c...recessed portion, 201S...waveguide surface, 201t, 201st...thick portion, 202...rod, 202A to 202D...rod-shaped conductor, 202E to 202F...wall portion, 203...opening portion, 201h, 204, 204A, 204B, 220...through hole, 204S...slit, 206...space, 210...electromagnetic wave shielding wall, 270...radiation hole, 300, 300A to 300C, 305, 306, 309, 310, 311...core conductor, 302...upper power supply portion, 303, 304, 307, 308...lower power supply conductor, 400...restraint member, 410...solder material, 500...conductor, 600...radar device

Claims

1. a substrate having an upper surface and a lower surface; a high-frequency circuit disposed on the upper surface or on the upper surface side of the substrate, the high-frequency circuit having a terminal for transmitting or receiving and a signal ground terminal; a first member disposed along the bottom surface of the substrate or on the bottom surface side of the substrate, the first member having a conductive bottom surface electrically connected to the signal ground terminal of the high-frequency circuit; a first waveguide including a core conductor that passes through the substrate and the first member in the vertical direction, and a peripheral conductor that is disposed along the core conductor around the core conductor with an insulator interposed therebetween and that is in contact with the conductive lower surface of the first member; a second member disposed along the first member on a lower surface side thereof and having a conductive upper surface; a ridge disposed between the first member and the second member, the ridge having a waveguide surface that is a strip-shaped conductive upper surface facing the conductive lower surface of the first member; a second waveguide formed by the waveguide surface of the ridge and the conductive lower surface of the first member; an electromagnetic wave blocking wall disposed between the first member and the second member and adjacent to a side of the second waveguide; an upper feeding portion disposed on the upper surface of the substrate and electromagnetically connecting the transmission or reception terminal of the high-frequency circuit to an end of the core conductor on the upper surface side of the substrate; a lower feed conductor that contacts or high-frequency couples the lower end of the core conductor on the lower surface side of the first member with the upper surface of the ridge located below the lower end.

2. 2. The waveguide device according to claim 1, wherein the core conductor and the lower feed conductor are configured as a core extension conductor formed continuously from the same material.

3. 3. The waveguide device according to claim 1, wherein the upper feeding portion is a waveguide formed by a microstrip line, a coplanar line, or a post wall.

4. 3. The waveguide device according to claim 2, wherein a plurality of through via holes are provided around the microstrip line or the coplanar line so as to surround the microstrip line or the coplanar line.

5. 4. The waveguide device according to claim 3, wherein an upper end of the core conductor is formed on an upper surface of a substrate outside an MMIC package that constitutes the high-frequency circuit.

6. 3. The waveguide device according to claim 1, wherein the upper power supply portion is configured to bring the terminal for transmitting or receiving of the high-frequency circuit into contact with the end of the core conductor on the upper surface side of the substrate, and to bring the peripheral conductor into contact with a ground used for transmitting or receiving of the high-frequency circuit.

7. The waveguide device according to claim 6 , wherein the terminal for transmitting or receiving and the end of the core conductor on the upper surface side of the substrate are arranged at positions that overlap each other in a vertical stereoscopic view.

8. 7. The waveguide device according to claim 6, wherein one end of a pin-shaped conductor is arranged in contact with the terminal for transmitting or receiving, and the pin-shaped conductor constitutes the core conductor and the lower feed conductor.

9. 7. The waveguide device according to claim 6, wherein the terminal for transmitting or receiving contacts one end of a socket pin of an IC socket arranged on the substrate, the socket pin constituting the core conductor and the lower feed conductor.

10. 3. A waveguide device according to claim 1, wherein a lower end of the lower feed conductor is disposed on an upper surface of the ridge or in a recess or through-hole formed in the upper surface of the ridge, and is in contact with or high-frequency coupled to the ridge.

11. 3. A waveguide device according to claim 1, wherein a lower end of the lower feed conductor is arranged opposite one end face of the ridge in the direction in which the ridge extends or is arranged within a through slit formed in the ridge, and is in contact with or high-frequency coupled to the ridge.

12. The waveguide device according to claim 10 , wherein the inner diameter of the recess or the through hole is equal to or less than half the wavelength of the electromagnetic wave propagating through the second waveguide.

13. 11. A waveguide device according to claim 10, further comprising: an uneven portion provided on the upper surface of the ridge adjacent to the lower end of the lower power supply conductor; a thickness-changing portion provided on the left and right side surfaces in the direction in which the ridge extends; or a convex portion provided on the end face of the ridge or the end face of the through slit in the direction in which the ridge extends.

14. 2. The waveguide device according to claim 1, wherein the core conductor has a substrate-side recess at its lower end, the lower power supply conductor has a tapered side at its upper end that narrows from bottom to top, and the upper end is inserted into the substrate-side recess and is in contact with the core conductor.

15. 3. The waveguide device according to claim 2, wherein the substrate has a through hole around the side surface of the portion corresponding to the core conductor, the core extension conductor has a tapered side surface at the upper end that narrows from bottom to top, and the upper end is in contact with the upper power supply portion.

16. 3. A waveguide device according to claim 1, further comprising a ridge-side recess formed on an upper surface of the ridge, the lower end of the lower feed conductor having a tapered side that narrows from top to bottom, the lower end of the lower feed conductor being inserted into the ridge-side recess, and the lower feed conductor and the ridge being in contact with each other.

17. 3. A waveguide device according to claim 1, wherein the ridge and the second member have a ridge through-hole that penetrates the ridge and the second member in the vertical direction, and a lower portion of the lower feed conductor is inserted into the ridge through-hole and is in contact with or high-frequency coupled to the ridge.

18. 3. A waveguide device according to claim 1, wherein the ridge and the second member have a ridge through-hole that penetrates the ridge and the second member in the vertical direction, and a lower portion of the lower power supply conductor is inserted into the ridge through-hole and is in contact with the second member that constitutes the ridge via solder.

19. 3. The waveguide device according to claim 1, wherein a conductive elastic body is disposed on an upper end of the lower power supply conductor, and a lower end of the lower power supply conductor is biased toward an upper surface of the ridge by the conductive elastic body and is in contact with the upper surface.

20. a first rod-shaped conductor has one end of the ridge adjacent to a portion of the upper surface of the ridge that is in contact with or high-frequency coupled with a lower end of the lower feed conductor, and is disposed on the upper surface of the second member at a position beyond the end of the ridge in the extending direction of the ridge; 3. The waveguide device according to claim 1, wherein a second rod-shaped conductor is disposed on the second member at a position beyond the other end of the ridge in the extending direction.

21. 21. The waveguide device according to claim 20, wherein an upper end of the first rod-shaped conductor or the second rod-shaped conductor is in contact with or high-frequency coupled to a lower surface of the first member.

22. 22. The waveguide device according to claim 21, wherein the width of the wall portion of the first rod-shaped conductor or the second rod-shaped conductor in a direction along the extension direction of the ridge and in a direction perpendicular to the height direction has a length of at least 1 / 4 of the free space wavelength λo of an electromagnetic wave at a center frequency of an operating frequency band.

23. 3. The waveguide device according to claim 1, wherein the core conductor and the peripheral conductor each comprise a single conductor, and the single peripheral conductor is disposed adjacent to the single core conductor.

24. 3. The waveguide device according to claim 1, wherein the core conductor is made of one conductor, the peripheral conductor is made of two conductors, and the core conductor is disposed between the two peripheral conductors.

25. 3. A waveguide device according to claim 1 or 2, wherein the core conductor consists of one conductor, the peripheral conductor consists of multiple linear conductors, and the multiple peripheral conductors are arranged along a portion of the outer periphery of the single core conductor, or the multiple peripheral conductors, approximately half of the multiple peripheral conductors, are arranged along a portion of the outer periphery of the single core conductor, and the remaining half of the multiple peripheral conductors are arranged along the periphery of another portion opposite the portion of the outer periphery.

26. 3. The waveguide device according to claim 1, wherein the core conductor consists of a single conductor, the peripheral conductor consists of a plurality of linear conductors or a plurality of plate-shaped conductors, and the plurality of peripheral conductors are arranged along almost the entire circumference of the single core conductor.

27. 3. The waveguide device according to claim 1, wherein the core conductor is made of a single conductor, the peripheral conductor is made of a single cylindrical conductor, and the peripheral conductor is arranged to surround the outer periphery of the single core conductor.

28. 3. The waveguide device according to claim 1, wherein the first member is formed of a ground pattern formed on the lower surface of the substrate.

29. 3. The waveguide device according to claim 1, wherein the electromagnetic wave blocking wall is composed of rods having conductive surfaces on the top and side surfaces formed on at least one of the bottom surface of the first member and the top surface of the second member, and wherein a plurality of the rods block propagation of electromagnetic waves in directions other than the propagation direction defined by the ridge, at least at the operating frequency.

30. 3. The waveguide device according to claim 1, wherein the electromagnetic wave blocking wall is composed of conductive posts that join the lower surface of the first member and the upper surface of the second member, and the plurality of posts block the propagation of electromagnetic waves in directions other than the propagation direction defined by the ridge, at least at the operating frequency.

31. 3. The waveguide device according to claim 1, wherein the electromagnetic wave blocking wall has an EBG (Electromagnetic Band Gap) structure formed on at least one of the lower surface of the first member and the upper surface of the second member, and the EBG structure blocks propagation of electromagnetic waves in directions other than the propagation direction defined by the ridge, at least at an operating frequency.

32. the high frequency circuit has a plurality of terminals for transmitting or receiving; a plurality of the first waveguides corresponding one-to-one to the plurality of terminals for transmitting or receiving; a plurality of second waveguides each corresponding to one of the plurality of first waveguides; a plurality of the lower feed conductors corresponding one-to-one to the plurality of second waveguides, The waveguide device according to claim 10, wherein the plurality of lower power supply conductors are bundled by an insulating restraining member so that their lower ends can be inserted into the upper surface of the corresponding ridge, the recess formed on the upper surface, or the through hole.

33. A waveguide device according to claim 1 or 2; A radar device comprising: a waveguide that vertically penetrates the second member adjacent to the end of the ridge in the extension direction; a rod-shaped conductor or wall portion that faces the end of the ridge in the extension direction of the ridge; and an antenna radiating element that radiates electromagnetic waves that have propagated through the waveguide.

34. A waveguide device according to claim 1 or 2; an antenna radiating element; one or more waveguides for propagating electromagnetic waves between the second waveguide and the antenna radiating element; a radar calculation unit that calculates position and relative velocity information of a detection target based on the electromagnetic waves transmitted and received by the antenna radiating element.

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