Terahertz device

Abstract

To increase antenna gain of a terahertz device.SOLUTION: A terahertz device 10 includes a terahertz element 50 and a reflector 40. The terahertz element 50 has an element main surface 51, and an element rear surface 52 facing the opposite side of the element main surface 51. The terahertz element 50 emits electromagnetic waves of a terahertz band, wherein a direction perpendicular to the element main surface 51 is defined as a z-direction. The reflector 40 is arranged at a position facing the element main surface 51 at an interval in the z-direction. The reflector 40 has a reflection plane 47a. The reflection plane 47a reflects the electromagnetic waves emitted by the terahertz element 50 in the z-direction to a direction crossing the z-direction.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to terahertz devices. [Background technology]

[0002] In recent years, as electronic devices such as transistors have become increasingly miniaturized and their size has reached nanoscale, a phenomenon known as the quantum effect has become observable. Development is underway to utilize this quantum effect to realize ultrafast devices and devices with new functions.

[0003] In such an environment, attempts are being made to utilize electromagnetic waves in the frequency range known as the terahertz band, which has a frequency range of 0.1 THz to 10 THz, for high-capacity communication, information processing, imaging, measurement, etc. This frequency range combines the properties of both light and radio waves, and if devices operating in this frequency band can be realized, they could be used for a wide range of applications, including the aforementioned imaging, high-capacity communication, and information processing, as well as measurements in various fields such as physical properties, astronomy, and biology.

[0004] As an element for emitting or receiving electromagnetic waves in the terahertz band, for example, an element having a structure in which a resonant tunneling diode and a fine slot antenna are integrated is known (see, for example, Patent Document 1). For example, Patent Document 2 discloses a terahertz device having a configuration in which elements such as those in Patent Document 1 are packaged. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-111542 [Patent Document 2] Japanese Patent Application Publication No. 2019-75544

[0006] [overview] However, there is room for improvement in antenna gain compared to conventional terahertz devices.

[0007] A terahertz device according to one aspect of the present disclosure includes a terahertz element having a main element surface and a back element surface facing the opposite side to the main element surface, emitting electromagnetic waves in the terahertz band and having a thickness direction perpendicular to the main element surface, and a reflector positioned opposite the main element surface with a gap in the thickness direction, the reflector having a reflective surface that reflects the electromagnetic waves emitted by the terahertz element in the thickness direction in a direction intersecting the thickness direction. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of the terahertz device according to the first embodiment. [Figure 2] FIG. 2 is a plan view of the terahertz device of FIG. 1 with the reflector omitted. [Figure 3] FIG. 3 is a plan view of the terahertz device of FIG. 2 with the waveguide omitted. [Figure 4] FIG. 4 is an end view showing the end face structure of the terahertz device of the first embodiment. [Figure 5] FIG. 5 is a rear view of the terahertz device of FIG. [Figure 6] FIG. 6 is an end view schematically showing an active element and its periphery. [Figure 7] FIG. 7 is an enlarged end view showing the end surface structure of the active element of FIG. [Figure 8] FIG. 8 is an enlarged plan view showing the terahertz element and its surroundings. [Figure 9] FIG. 9 is a perspective view of the reflector. [Figure 10] FIG. 10 is an end view showing the end face structure in a direction different from the end face structure in FIG. 4 of the terahertz device of the first embodiment. [Figure 11] FIG. 11 is an end view of a terahertz device of a comparative example. [Figure 12]FIG. 12 is a side view of the terahertz device according to the second embodiment. [Figure 13] FIG. 13 is an exploded perspective view of the terahertz device of FIG. [Figure 14] FIG. 14 is a rear view of the reflector. [Figure 15] FIG. 15 is a side view of the reflector. [Figure 16] FIG. 16 is a front view of the reflector. [Figure 17] FIG. 17 is an end view showing the end face structure of the terahertz device according to the second embodiment. [Figure 18] FIG. 18 is a perspective view of the terahertz device according to the third embodiment. [Figure 19] FIG. 19 is a plan view of the support substrate of the terahertz device of FIG. [Figure 20] FIG. 20 is an end view showing the end face structure of the terahertz device according to the third embodiment. [Figure 21] FIG. 21 is an end view showing the end face structure of the terahertz device according to the fourth embodiment. [Figure 22] FIG. 22 is a plan view of the terahertz device according to the fourth embodiment, from which the reflector and the antenna portion of the waveguide are omitted. [Figure 23] FIG. 23 is an explanatory diagram of phase matching in the terahertz device of the fourth embodiment. [Figure 24] FIG. 24 is an end view showing the end face structure of a modified terahertz device. [Figure 25] FIG. 25 is an end view showing the end face structure of a modified terahertz device. [Figure 26] FIG. 26 is an end view showing the end face structure of a modified terahertz device. [Figure 27] FIG. 27 is an end view showing the end face structure of a modified terahertz device. [Figure 28] FIG. 28 is an end view showing the end face structure of a modified terahertz device. [Figure 29] FIG. 29 is an end view showing the end face structure of a modified terahertz device. [Figure 30]FIG. 30 is an enlarged end view of the terahertz element and its surroundings in the end face structure of the terahertz device according to the modified example. [Figure 31] FIG. 31 is an enlarged end view of the terahertz element and its surroundings in the end face structure of the terahertz device according to the modified example.

[0009] [Detailed explanation] Hereinafter, embodiments of the terahertz device will be described with reference to the drawings. The embodiments shown below are intended to exemplify configurations and methods for embodying the technical ideas, and are not intended to limit the materials, shapes, structures, arrangements, dimensions, etc. of the components to those described below. Various modifications can be made to the following embodiments.

[0010] [First embodiment] A terahertz device 10 according to a first embodiment will be described with reference to Figures 1 to 9. Note that Figure 2 shows a plan view of the terahertz device 10 with a reflector 40, which will be described later, omitted.

[0011] 1, the terahertz device 10 has a configuration in which a support substrate 20, a waveguide 30, and a reflector 40 are stacked. The support substrate 20 is formed in a rectangular plate shape, the waveguide 30 is formed in a rectangular parallelepiped shape, and the reflector 40 is formed in a substantially rectangular parallelepiped shape with one end open. In this embodiment, the waveguide 30 is stacked on the support substrate 20, and the reflector 40 is stacked on the waveguide 30.

[0012] In the following description, the stacking direction of the support substrate 20, the waveguide 30, and the reflector 40 is referred to as the z direction, and two mutually orthogonal directions orthogonal to the z direction are referred to as the x direction and the y direction. The z direction can also be said to be the height direction of the terahertz device 10. When viewed from the z direction, the x direction forms one side of the terahertz device 10, and the y direction forms the other side of the terahertz device 10.

[0013] 1 and 2, the terahertz device 10 has a device principal surface 11 and a device rear surface 12 that constitute both end surfaces of the terahertz device 10 in the z direction, and four device side surfaces 13 to 16 that are located between the device principal surface 11 and the device rear surface 12 in the z direction and intersect with the device principal surface 11 and the device rear surface 12. In this embodiment, the device principal surface 11 and the device rear surface 12 face opposite each other in the z direction, and each of the device side surfaces 13 to 16 is perpendicular to the device principal surface 11 and the device rear surface 12. As shown in FIG. 2, a pair of device side surfaces 13 and 14 of the device side surfaces 13 to 16 that are spaced apart in the y direction constitute one side of the terahertz device 10 that is aligned in the x direction when viewed from the z direction. Furthermore, a pair of device side surfaces 15 and 16 of the four device side surfaces 13 that are spaced apart in the x direction constitute one side of the terahertz device 10 that is aligned in the y direction when viewed from the z direction.

[0014] The terahertz device 10 includes a terahertz element 50. The terahertz element 50 is an element that exchanges electromagnetic waves in the terahertz band with electrical energy. Note that the electromagnetic waves include the concepts of either light or radio waves, or both. The terahertz element 50 converts electrical energy supplied by oscillation into electromagnetic waves in the terahertz band. As a result, the terahertz element 50 emits electromagnetic waves in the terahertz band, in other words, terahertz waves. The frequency of the electromagnetic waves is, for example, 0.1 to 10 kHz. The detailed configuration of the terahertz element 50 will be described later.

[0015] 3, the support substrate 20 is a substrate that supports the terahertz device 50. The support substrate 20 is made of an electrically insulating material, such as a resin material. An example of such a resin material is epoxy resin.

[0016] As shown in Fig. 3, in this embodiment, the support substrate 20 has a square shape when viewed from the z direction. As shown in Figs. 3 and 4, the support substrate 20 has a substrate main surface 21 and a substrate back surface 22 that face opposite each other in the z direction, and four substrate side surfaces 23 to 26 that are located between the substrate main surface 21 and the substrate back surface 22 in the z direction and intersect with the substrate main surface 21 and the substrate back surface 22. In this embodiment, each of the substrate side surfaces 23 to 26 is perpendicular to the substrate main surface 21 and the substrate back surface 22. In this embodiment, the z direction can also be said to be a direction perpendicular to both the substrate main surface 21 and the substrate back surface 22.

[0017] As shown in FIG. 4, the substrate main surface 21 faces in the same direction as the device main surface 11, and the substrate back surface 22 faces in the same direction as the device back surface 12. In this embodiment, the substrate back surface 22 constitutes the device back surface 12. As shown in FIG. 3, the substrate side surface 23 faces in the same direction as the device side surface 13, the substrate side surface 24 faces in the same direction as the device side surface 14, the substrate side surface 25 faces in the same direction as the device side surface 15, and the substrate side surface 26 faces in the same direction as the device side surface 16. In other words, the substrate side surfaces 23 to 26 constitute part of the device side surfaces 13 to 16. As shown in FIG. 4, a waveguide 30 is stacked on the substrate main surface 21. A terahertz element 50 is mounted at the center of the substrate main surface 21 in the x and y directions.

[0018] 4, the support substrate 20 has a power supply line 27 as a transmission path connected to the terahertz element 50, an exterior terminal 28 for electrically connecting the terahertz device 10 to an external electronic device, and a connection conductor 29 connecting the power supply line 27 and the exterior terminal 28. The power supply line 27 is formed on the main surface 21 of the support substrate 20. The exterior terminal 28 is formed on the rear surface 22 of the support substrate 20.

[0019] The feed line 27 of this embodiment is a coplanar line. Alternatively, the feed line 27 may be a microstrip line, a strip line, a slot line, or the like. The feed line 27 is made of, for example, Cu (copper). The feed line 27 has a main conductor 27a and a ground conductor 27b. The main conductor 27a and the ground conductor 27b are disposed on both sides of the terahertz element 50 in the x direction. In one example, when viewed from the z direction, the main conductor 27a is disposed closer to the substrate side surface 25 than the terahertz element 50, and the ground conductor 27b is disposed closer to the substrate side surface 26 than the terahertz element 50. These conductors 27a and 27b are formed in strip shapes extending in the x direction when viewed from the z direction. In one example, the length of these conductors 27a and 27b in the x direction is longer than the length of the terahertz element 50 in the x direction.

[0020] When viewed from the z direction, the main conductor 27a and the ground conductor 27b have the same shape. The main conductor 27a and the ground conductor 27b are aligned with each other in the x direction and spaced apart from each other in the y direction.

[0021] Exterior terminal 28 is made of, for example, a laminate of a Ni (nickel) layer, a Pd (palladium) layer, and an Au (gold) layer. As shown in Figures 4 and 5, exterior terminal 28 has main terminal 28a and ground terminal 28b corresponding to main conductor 27a and ground conductor 27b.

[0022] When viewed from the z direction, the main terminals 28a and the ground terminals 28b have the same shape. The main terminals 28a and the ground terminals 28b are arranged aligned with each other in the x direction and spaced apart from each other in the y direction.

[0023] In this embodiment, the areas of main terminal 28a and ground terminal 28b when viewed from the z direction are larger than the areas of main conductor 27a and ground conductor 27b when viewed from the z direction. More specifically, the lengths of main terminal 28a and ground terminal 28b in the x direction are longer than the lengths of main conductor 27a and ground conductor 27b in the x direction. The lengths of main terminal 28a and ground terminal 28b in the y direction are longer than the lengths of main conductor 27a and ground conductor 27b in the y direction.

[0024] The connecting conductor 29 is made of, for example, Cu. As shown in FIG. 4 , the connecting conductor 29 is provided so as to penetrate the support substrate 20. More specifically, a through hole 20a is formed in the support substrate 20 in a portion corresponding to the main conductor 27a and the ground conductor 27b. The through hole 20a penetrates the support substrate 20 in the z direction. The connecting conductor 29 is provided inside the through hole 20a. In this embodiment, the shape of the through hole 20a as viewed from the z direction is a rectangle whose long side is in the x direction and whose short side is in the y direction.

[0025] The connecting conductor 29 includes a main connecting conductor 29a that connects the main conductor 27a and the main terminal 28a, and a ground connecting conductor 29b that connects the ground conductor 27b and the ground terminal 28b. In this embodiment, as shown in Fig. 3, the shape of each of the connecting conductors 29a and 29b when viewed from the z direction is the same as the shape of the through hole 20a when viewed from the z direction.

[0026] As shown in FIGS. 4 and 5 , in this embodiment, a back surface insulating layer 20R is formed on the substrate back surface 22 of the support substrate 20. The back surface insulating layer 20R is a resist layer made of an electrically insulating resin material. The back surface insulating layer 20R functions as a marker for determining the connection direction of the terahertz device 10. The back surface insulating layer 20R is located near the center of the substrate back surface 22 in the x direction, between the main terminal 28a and the ground terminal 28b in the x direction. When viewed from the z direction, the back surface insulating layer 20R has a rectangular shape with a recess on the main terminal 28a side. The back surface insulating layer 20R is formed by curing a film-like resist attached to the substrate back surface 22. The back surface insulating layer 20R may be formed using a liquid resist. The recess in the back surface insulating layer 20R may be located on the ground terminal 28b side. In short, the back surface insulating layer 20R may be provided so that the connection direction of the terahertz device 10 can be determined by the recess.

[0027] 3, the terahertz element 50 mounted on the substrate main surface 21 is formed in the shape of a rectangular plate. In this embodiment, the shape of the terahertz element 50 when viewed from the z direction is, for example, a square. Note that the shape of the terahertz element 50 when viewed from the z direction is not limited to a square, and may be a rectangle, a circle, an ellipse, or a polygon.

[0028] 3 and 4 , the terahertz element 50 has an element principal surface 51, an element back surface 52 facing the opposite side to the element principal surface 51, and element side surfaces 53 to 56 located between the element principal surface 51 and the element back surface 52 in the z direction and intersecting with the element principal surface 51 and the element back surface 52. The thickness direction of the terahertz element 50 is a direction perpendicular to the element principal surface 51. Here, since the element principal surface 51 is formed as an xy plane, the z direction can also be said to be the thickness direction of the terahertz element 50. In this embodiment, since the element back surface 52 is also formed as an xy plane, the thickness direction of the terahertz element 50 can also be said to be a direction perpendicular to both the element principal surface 51 and the element back surface 52.

[0029] The element principal surface 51 faces the same side as the substrate principal surface 21, and the element back surface 52 faces the same side as the substrate back surface 22. Therefore, the terahertz element 50 is mounted on the substrate principal surface 21 so that the element back surface 52 faces the substrate principal surface 21. In this embodiment, the terahertz element 50 is attached to the support substrate 20 with the element back surface 52 in contact with the substrate principal surface 21 or facing the substrate principal surface 21 via an intermediate layer. An example of the intermediate layer is an adhesive layer.

[0030] The terahertz element 50 has a radiation pattern that radiates electromagnetic waves in a direction perpendicular to both the element principal surface 51 and the element rear surface 52, that is, in the z direction which is the thickness direction of the terahertz element 50. In this embodiment, the terahertz element 50 radiates electromagnetic waves in a direction away from the support substrate 20 in the z direction. Since the power supply line 27 is formed on the substrate principal surface 21 of the support substrate 20, it can also be said that the power supply line 27 is arranged on the opposite side of the element principal surface 51 of the terahertz element 50 in the z direction to the radiation direction of the electromagnetic waves of the terahertz element 50.

[0031] In this embodiment, the element side surfaces 53 to 56 are perpendicular to the element main surface 51 and the element back surface 52. The element side surface 53 faces the same side as the substrate side surface 23, the element side surface 54 faces the same side as the substrate side surface 24, the element side surface 55 faces the same side as the substrate side surface 25, and the element side surface 56 faces the same side as the substrate side surface 26.

[0032] 6 and 7 show an example of a detailed configuration of the terahertz element 50. Fig. 6 is an example of a schematic cross-sectional view of the cross-sectional structure of the terahertz element 50, and Fig. 7 is a partially enlarged view of Fig. 6. As shown in FIGS. 6 and 7, the terahertz device 50 includes an element substrate 61, an active element 62, a first conductive layer 63, and a second conductive layer 64.

[0033] The element substrate 61 is made of a semiconductor and has semi-insulating properties. The semiconductor that constitutes the element substrate 61 is, for example, InP (indium phosphide), but may be a semiconductor other than InP. When the element substrate 61 is made of InP, its refractive index (absolute refractive index) is approximately 3.4. In this embodiment, the element substrate 61 has a rectangular plate shape, for example, a square shape when viewed from the z direction. The element main surface 51 and the element back surface 52 are the main surface and back surface of the element substrate 61, and each of the element side surfaces 53 to 56 is each of the side surfaces of the element substrate 61.

[0034] The active element 62 converts electromagnetic waves in the terahertz band into electrical energy. The active element 62 is provided on the element substrate 61. In this embodiment, the active element 62 is provided at the center of the element principal surface 51. The active element 62 is connected to the antenna 65 to convert supplied electrical energy into electromagnetic waves in the terahertz band. This causes the terahertz element 50 to emit electromagnetic waves in the terahertz band (terahertz waves). Therefore, the active element 62 can be referred to as an oscillation point P1 that oscillates terahertz waves, and the antenna 65 can be referred to as a radiation point P2 that radiates terahertz waves. The terahertz element 50 of this embodiment has the radiation point P2 at the center of the element principal surface 51. In this embodiment, the terahertz element 50 has the radiation point P2 and the oscillation point P1 at the same position.

[0035] The active element 62 is typically a resonant tunneling diode (RTD), but may also be, for example, a tunnel injection transit time (TUNNETT) diode, an impact ionization avalanche transit time (IMPATT) diode, a GaAs field effect transistor (FET), a GaN FET, a high electron mobility transistor (HEMT), or a heterojunction bipolar transistor (HBT).

[0036] An example for realizing the active element 62 will now be described. A semiconductor layer 71a is formed on the element substrate 61. The semiconductor layer 71a is made of, for example, GaInAs, and is doped with a high concentration of n-type impurities.

[0037] A GaInAs layer 72a is stacked on the semiconductor layer 71a. The GaInAs layer 72a is doped with n-type impurities. For example, the impurity concentration of the GaInAs layer 72a is lower than the impurity concentration of the semiconductor layer 71a.

[0038] A GaInAs layer 73a is stacked on the GaInAs layer 72a. The GaInAs layer 73a is not doped with impurities. An AlAs layer 74a is stacked on the GaInAs layer 73a, an InGaAs layer 75 is stacked on the AlAs layer 74a, and an AlAs layer 74b is stacked on the InGaAs layer 75. The AlAs layer 74a, the InGaAs layer 75, and the AlAs layer 74b form a resonant tunnel section.

[0039] An undoped GaInAs layer 73b is stacked on the AlAs layer 74b. An n-type doped GaInAs layer 72b is stacked on the GaInAs layer 73b. A GaInAs layer 71b is stacked on the GaInAs layer 72b. The GaInAs layer 71b is doped with a high concentration of n-type impurities. For example, the impurity concentration of the GaInAs layer 71b is higher than that of the GaInAs layer 72b.

[0040] The specific configuration of the active element 62 can be changed as desired as long as it can generate (or detect, or both) electromagnetic waves. In other words, the active element 62 may be any element that can perform at least one of oscillation and detection of electromagnetic waves in the terahertz band.

[0041] 8, the terahertz element 50 has an oscillation point P1 that oscillates an electromagnetic wave. The oscillation point P1 is formed on the element main surface 51. The element main surface 51 having the oscillation point P1 can also be referred to as an active surface. The oscillation point P1 can also be referred to as a position where the active element 62 is provided.

[0042] In this embodiment, the radiation point P2 (antenna 65) is disposed at the center of the element principal surface 51. However, the position of the radiation point P2, in other words, the position of the antenna 65 relative to the element principal surface 51, is not limited to the center of the element principal surface 51 and can be arbitrarily changed. Furthermore, the oscillation point P1 (active element 62) is not limited to the same position as the radiation point P2 and can be arbitrarily changed.

[0043] As shown in FIG. 8, the first conductive layer 63 and the second conductive layer 64 are each formed on the element principal surface 51. The first conductive layer 63 and the second conductive layer 64 are insulated from each other. The first conductive layer 63 and the second conductive layer 64 each have a metal laminate structure. The laminate structure of each of the first conductive layer 63 and the second conductive layer 64 is, for example, a structure in which Au, Pd, and Ti (titanium) are laminated. Alternatively, the laminate structure of each of the first conductive layer 63 and the second conductive layer 64 is a structure in which Au and Ti are laminated. Both the first conductive layer 63 and the second conductive layer 64 are formed by vacuum deposition, sputtering, or the like.

[0044] The first conductive layer 63 has a first conductive portion 63a, a first connecting portion 63b, and a first pad electrode 63c. The second conductive layer 64 has a second conductive portion 64a, a second connecting portion 64b, and a second pad electrode 64c. The first pad electrode 63c corresponds to a main electrode, and the second pad electrode 64c corresponds to a ground electrode.

[0045] The first conductive portion 63a and the second conductive portion 64a extend in opposite directions from the active element 62 in a direction (y direction) perpendicular to the element side surfaces 53 and 54 of the terahertz element 50. That is, the first conductive portion 63a and the second conductive portion 64a are parallel to the element side surfaces 55 and 56 of the terahertz element 50.

[0046] The first conductive portion 63a and the second conductive portion 64a function as an antenna 65. The terahertz element 50 has the antenna 65 integrated on the element principal surface 51 side by the first conductive portion 63a which is part of the first conductive layer 63 and the second conductive portion 64a which is part of the second conductive layer 64. That is, the terahertz element 50 has an active element 62 which oscillates electromagnetic waves with a frequency in the terahertz band, and the antenna 65 which emits the electromagnetic waves with a radiation pattern in a direction perpendicular to the element principal surface 51.

[0047] Antenna 65 is, for example, a dipole antenna. The length from the tip of first conductive portion 63a to the tip of second conductive portion 64a, i.e., the length of the antenna, is 1 / 2 wavelength (λ / 2) of the electromagnetic wave emitted by terahertz element 50. Note that the antenna is not limited to a dipole antenna, and may be other antennas such as a bowtie antenna, a slot antenna, a patch antenna, or a ring antenna. The length of the antenna may be changed depending on the antenna configuration.

[0048] The first connection portion 63b extends in the x direction and connects the first conductive portion 63a and the first pad electrode 63c. The second connection portion 64b extends in the x direction and connects the second conductive portion 64a and the second pad electrode 64c. The first pad electrode 63c and the second pad electrode 64c are spaced apart from each other in the y direction and are insulated from each other.

[0049] In this embodiment, the terahertz element 50 has a metal insulator metal (MIM) reflector 66. The MIM reflector 66 has a layered structure made of metal / insulator / metal. For example, the MIM reflector 66 is configured by sandwiching an insulator between a part of the first pad electrode 63c and a part of the second pad electrode 64c in the thickness direction (z direction) of the terahertz element 50. The insulator may be, for example, a SiO2 film, a Si3N4 film, a HfO2 film, an Al2O3 film, or the like.

[0050] The MIM reflector 66 short-circuits the first conductive layer 63 and the second conductive layer 64 at high frequencies. The MIM reflector 66 can reflect high-frequency electromagnetic waves. The MIM reflector 66 functions as a low-pass filter. However, the MIM reflector 66 is not essential and may be omitted.

[0051] 6 and 7, in this embodiment, a first conductive portion 63a and a second conductive portion 64a are arranged on both sides of the active element 62 in the y direction. The first conductive portion 63a has a first connection region 63d that overlaps with the active element 62 when viewed from the z direction. The first connection region 63d is located on the GaInAs layer 71b and is in contact with the GaInAs layer 71b.

[0052] As shown in Fig. 6, the semiconductor layer 71a extends further in the y-direction toward the second conductive portion 64a than other layers, such as the GaInAs layer 72a. As shown in Figs. 6 and 7, the second conductive portion 64a has a second connection region 64d that is stacked in a portion of the semiconductor layer 71a where the GaInAs layer 72a and other layers are not stacked. This establishes electrical continuity between the active element 62 and the first conductive portion 63a and the second conductive portion 64a. The second connection region 64d and other layers, such as the GaInAs layer 72a, are spaced apart in the y-direction.

[0053] Although not shown, a GaInAs layer doped with a high concentration of n-type impurities may be interposed between the GaInAs layer 71b and the first connection region 63d, unlike in Fig. 7. This improves the contact between the first conductive portion 63a and the GaInAs layer 71b.

[0054] 8, the first pad electrode 63c is electrically connected to the main conductor 27a of the support substrate 20 by a wire W1. The second pad electrode 64c is electrically connected to the ground conductor 27b of the support substrate 20 by a wire W2. Alternatively, the first pad electrode 63c may be connected to the ground conductor 27b, and the second pad electrode 64c may be connected to the main conductor 27a. There may be multiple wires W1 and W2. The number of wires W1 and W2 may be different.

[0055] In the terahertz element 50, the dimension in the x direction is defined as element dimension x0, and the dimension in the y direction is defined as element dimension y0. These element dimensions x0 and y0 are set based on the dielectric resonator antenna.

[0056] In this embodiment, the radiation point P2 is set at the center of the terahertz element 50. If the distance from the radiation point P2 to the element side surface 55 is x1, this distance x1 is 1 / 2 of the element dimension x0. This distance x1 (= x0 / 2) is preferably (λ1 / 2) + ((λ1 / 2) × N (N is an integer equal to or greater than 0: N = 0, 1, 2, 3, ...)). λ1 is the effective wavelength of the electromagnetic wave propagating inside the terahertz element 50 (element substrate 51). When the refractive index of the terahertz element 50 (element substrate 51) is n1, c is the speed of light, and fc is the center frequency of the electromagnetic wave, λ1 is (1 / n1) × (c / fc). Similarly, if the distance from the radiation point P2 to the element side surface 53 is y1, this distance y1 is 1 / 2 of the element dimension y0. This y1 (= y0 / 2) should be (λ1 / 2) + ((λ1 / 2) × N (N is an integer equal to or greater than 0: N = 0, 1, 2, 3 ...)). By setting the distances x1 and y1, i.e., the element dimensions x0 and y0, in this way, the electromagnetic waves radiated from the antenna 65 are reflected by the free ends of the element side surfaces 53 to 56. Therefore, the terahertz element 50 itself is designed as a resonator (primary resonator) in the terahertz device 10.

[0057] Note that the distance from radiation point P2 to each of element side surfaces 53-56 may be a different value for each of element side surfaces 53-56, as long as it is a value calculated using the above formula. For example, in Fig. 8, the distance from radiation point P2 to element side surface 53 may be different from the distance from radiation point P2 to element side surface 54. Similarly, the distance from radiation point P2 to element side surface 55 may be different from the distance from radiation point P2 to element side surface 56.

[0058] 1, 2, and 4, waveguide 30 is a hollow metal tube that transmits electromagnetic waves. Waveguide 30 is made of a conductive material that is non-transparent to the electromagnetic waves emitted or received by terahertz element 50. This material may be Cu, a Cu alloy, Al, an Al alloy, or the like.

[0059] As shown in Fig. 2, in this embodiment, the waveguide 30 has a square shape when viewed from the z direction. As shown in Fig. 2 and Fig. 4, the waveguide 30 has a tube main surface 31 and a tube back surface 32 that face opposite each other in the z direction, and four tube side surfaces 33 to 36 that are located between the tube main surface 31 and the tube back surface 32 in the z direction and intersect with the tube main surface 31 and the tube back surface 32. In this embodiment, each of the tube side surfaces 33 to 36 is perpendicular to the tube main surface 31 and the tube back surface 32.

[0060] 2 and 3, the tube side surface 33 faces the same side as the substrate side surface 23, the tube side surface 34 faces the same side as the substrate side surface 24, the tube side surface 35 faces the same side as the substrate side surface 25, and the tube side surface 36 faces the same side as the substrate side surface 26. In this embodiment, the tube side surface 33 and the substrate side surface 23 are flush with each other, the tube side surface 34 and the substrate side surface 24 are flush with each other, the tube side surface 35 and the substrate side surface 25 are flush with each other, and the tube side surface 36 and the substrate side surface 26 are flush with each other. In this manner, the tube side surface 33 forms part of the device side surface 13, the tube side surface 34 forms part of the device side surface 14, the tube side surface 35 forms part of the device side surface 15, and the tube side surface 36 forms part of the device side surface 16.

[0061] 4, the waveguide 30 is mounted on the substrate main surface 21 of the support substrate 20, and houses the terahertz element 50. More specifically, the waveguide 30 is mounted on the substrate main surface 21 via a first adhesive layer AH1.

[0062] The waveguide 30 has a through hole 37 that penetrates the waveguide 30 in the z direction. As shown in Fig. 2, the shape of the through hole 37 when viewed from the z direction is circular. As shown in Fig. 4, the through hole 37 is formed so that its diameter increases from the rear surface 32 of the waveguide toward the main surface 31 of the waveguide. That is, the through hole 37 has a tapered surface 37a whose diameter increases as it becomes more distant from the support substrate 20 in the z direction, in other words, as it becomes more distant from the terahertz element 50 in the z direction.

[0063] The shape of through-hole 37 as viewed from the z direction can be changed as desired. For example, the shape of through-hole 37 as viewed from the z direction may be a rectangle, a polygon with pentagons or more sides, an ellipse, or an oval (track shape).

[0064] The through hole 37 functions as a transmission region 38 that transmits electromagnetic waves. The transmission region 38 is defined by a tapered surface 37a of the through hole 37. The transmission region 38 of this embodiment is circular when viewed from the z direction. That is, the waveguide 30 of this embodiment is a circular waveguide.

[0065] By mounting the waveguide 30 on the support substrate 20, one side of the through-hole 37 in the z direction, in other words, one side of the transmission region 38 in the z direction, is closed. The waveguide 30 is mounted on the support substrate 20 (terahertz element 50) so that the central axis J of the waveguide 30 coincides with the radiation point P2 of the terahertz element 50. Here, the central axis J of the waveguide 30 is an imaginary axis that passes through the center of the through-hole 37 when viewed from the z direction and extends along the z direction. In other words, the waveguide 30 accommodates the terahertz element 50. More specifically, the terahertz element 50 is disposed in the transmission region 38.

[0066] Furthermore, in this embodiment, the waveguide 30, the support substrate 20, and the terahertz element 50 are arranged so that the radiation direction of the electromagnetic waves from the terahertz element 50 is parallel to the central axis J of the waveguide 30. Therefore, the terahertz element 50 can be coupled to the waveguide 30 with high efficiency.

[0067] The reflector 40 is a reflective member that reflects the electromagnetic waves emitted by the terahertz element 50 in a direction intersecting the radiation direction of the electromagnetic waves. More specifically, the reflector 40 is a reflective member that reflects the electromagnetic waves transmitted from the terahertz element 50 via the waveguide 30 in a predetermined direction. The reflector 40 is configured as, for example, a horn reflector antenna. In this embodiment, the reflector 40 is made of a metal material. Examples of the metal material that can be used include Cu, a Cu alloy, Al (aluminum), and an Al alloy.

[0068] The reflector 40 has an opening 40A that is open on one side in the y direction, which is the one direction. More specifically, the opening 40A is open toward the device side surface 13. Therefore, it can be said that the opening 40A is open in a direction intersecting the thickness direction of the terahertz element 50. More specifically, it can be said that the opening 40A is open in a direction perpendicular to the thickness direction of the terahertz element 50. In this embodiment, the opening 40A is also open on the device back surface 12 side in the z direction.

[0069] As shown in Figures 4 and 10, the reflector 40 has a main surface 41 and a back surface 42 facing opposite each other in the z direction, and side surfaces 43 to 46 located between the main surface 41 and the back surface 42 in the z direction and intersecting with the main surface 41 and the back surface 42.

[0070] The main surface 41 faces the same side as the tube main surface 31, and the back surface 42 faces the same side as the tube back surface 32. The main surface 41 constitutes the device main surface 11. The side surface 43 faces the same side as the tube side surface 33, the side surface 44 faces the same side as the tube side surface 34, the side surface 45 faces the same side as the tube side surface 35, and the side surface 46 faces the same side as the tube side surface 36. In this embodiment, the side surface 44 is flush with the tube side surface 34, the side surface 45 is flush with the tube side surface 35, and the side surface 46 is flush with the tube side surface 36. In this way, the side surface 44 constitutes part of the device side surface 14, the side surface 45 constitutes part of the device side surface 15, and the side surface 46 constitutes part of the device side surface 16. Device side 13 consists of substrate side 23, tube side 33 and side 43, device side 14 consists of substrate side 24, tube side 34 and side 44, device side 15 consists of substrate side 25, tube side 35 and side 45, and device side 16 consists of substrate side 26, tube side 36 and side 46.

[0071] The side surface 43 is connected to the main surface 41 in the z direction and is spaced apart from the back surface 42 in the z direction. Each of the side surfaces 44 to 46 has a portion that connects the main surface 41 and the back surface 42 in the z direction. The side surface 44 is formed so that its entirety connects the main surface 41 and the back surface 42 in the z direction. Portions of the side surfaces 45 and 46 near the side surface 44 in the y direction connect the main surface 41 and the back surface 42 in the z direction. Portions of the side surfaces 45 and 46 near the side surface 43 in the y direction have inclined surfaces that slope toward the main surface 41 in the z direction as they approach the side surface 43 in the y direction. In other words, the portions of the side surfaces 45 and 46 near the side surface 43 in the y direction are open in the x direction.

[0072] Because the reflector 40 is open toward the device side surface 13, it can also be said that a device opening 17 is formed on the device side surface 13. It can also be said that the device opening 17 is open in a direction intersecting the thickness direction of the terahertz element 50. In this embodiment, the device opening 17 is open in a direction perpendicular to the thickness direction of the terahertz element 50. The device opening 17 of this embodiment is defined by the reflector 40 and the waveguide 30. It can also be said that the device opening 17 is an emission portion from which electromagnetic waves from the terahertz element 50 are emitted when the terahertz element 50 oscillates. In this embodiment, the device opening 17 is also open at portions of the device side surfaces 15 and 16 near the device side surface 13. In other words, it can also be said that the device opening 17 of this embodiment is open on both sides in the x direction. In this way, it is sufficient that the portion of the device opening 17 facing the terahertz element 50 in the thickness direction of the terahertz element 50 is not open in the thickness direction of the terahertz element 50. In other words, the device opening 17 is configured so that the electromagnetic waves emitted by the terahertz element 50 and reflected by the reflecting surface 47a of the reflector 40, which will be described later, can be emitted outside the terahertz device 10 in the propagation direction of the electromagnetic waves.

[0073] The reflector 40 is mounted on the waveguide 30 on the side opposite to the support substrate 20. More specifically, the reflector 40 is attached to the waveguide 30 via a second adhesive layer AH2. A back surface 42 of the reflector 40 faces the main surface 31 of the waveguide 30 in the z direction. The second adhesive layer AH2 is interposed between the back surface 42 and the main surface 31. In this embodiment, the back surface 42 is formed so as to surround three of the device side surfaces 14 to 16.

[0074] Reflector 40 has reflecting portion 47 that reflects electromagnetic waves emitted by terahertz element 50 in a direction intersecting the radiation direction of the electromagnetic waves. As shown in Fig. 4, reflecting portion 47 has reflecting surface 47a, which is a curved concave surface that curves from side surface 44 to side surface 43 as it moves from back surface 42 to main surface 41 in the y direction. As shown in Fig. 10, reflecting surface 47a is a curved concave surface that curves from the center of reflector 40 outward in the x direction toward back surface 42. In other words, reflector 40 has reflecting surface 47a that reflects electromagnetic waves emitted by terahertz element 50 in a direction intersecting the radiation direction of the electromagnetic waves (z direction).

[0075] Here, the end of the reflecting surface 47a that is on the side surface 43 side of the reflector 40 is referred to as the tip end 47b, and the end of the reflecting surface 47a that is on the back surface 42 side of the reflector 40 is referred to as the base end 47c. In this embodiment, the tip end 47b defines the opening 40A of the reflector 40, and it can be said that the device opening 17 is defined by the tip end 47b and the main surface 31 of the waveguide 30. In other words, it can be said that the device opening 17 is the region between the tip end 47b and the main surface 31 of the waveguide 30.

[0076] When the reflecting surface 47a of the reflecting portion 47 is formed by an aspherical surface, for example, in the cross-sectional view of the reflector 40 shown in FIG. 4, the reflecting surface 47a of the reflecting portion 47 has a yz coordinate system of y=z 2 / 4f. Here, y is a coordinate in the y direction, and z is a coordinate in the z direction. In FIG. 4, the edge of the reflecting surface 47a that contacts the back surface 42 is the origin of the y-z coordinate system. f is the distance between the portion of the reflecting surface 47a closest to the device side surface 14 (base end 47c) and the radiation point P2 of the terahertz element 50 in a direction perpendicular to the z direction. The z direction can also be considered as the thickness direction of the terahertz element 50, and the y direction can also be considered as the direction perpendicular to the thickness direction of the terahertz element 50, in which the electromagnetic waves emitted by the terahertz element 50 toward the reflecting surface 47a are reflected. In this embodiment, the reflecting surface 47a is formed as a paraboloid of revolution. More specifically, the reflecting surface 47a is formed by rotating the reflecting surface 47a around a central axis of rotation that is a straight line extending from the origin of the y-z coordinate system along the y direction.

[0077] As shown in FIGS. 4 and 10 , the reflecting surface 47a is disposed at a position facing the element principal surface 51 of the terahertz element 50 with a gap in the z direction. The reflecting surface 47a is provided so as to cover the terahertz element 50 from the z direction. The reflecting surface 47a is provided so as to cover the transmission region 38 from the z direction. More specifically, as shown in FIG. 4 , the reflecting surface 47a is provided so as to cover the entirety of both the terahertz element 50 and the transmission region 38 from the z direction in the y direction. The maximum value of the length of the reflecting surface 47a in the y direction is longer than the maximum value of the length of the through hole 37 of the waveguide 30 in the y direction. As shown in FIG. 10 , the reflecting surface 47a is provided so as to cover the entirety of both the terahertz element 50 (see FIG. 4 ) and the transmission region 38 from the z direction in the x direction. The maximum value of the length of the reflecting surface 47a in the x direction is longer than the maximum value of the length of the through hole 37 in the x direction.

[0078] 4, when viewed from the z direction, the reflecting surface 47a covers the entire area extending in the z direction from the tapered surface 37a of the waveguide 30 along the tapered surface 37a. In the present embodiment, as shown in Fig. 4, the tip 47b of the reflecting surface 47a extends from a portion of the tapered surface 37a of the through-hole 37 of the waveguide 30 that corresponds to the tube-side surface 33 to a position where it intersects with an imaginary line LV that extends in the z direction along the tapered surface 37a.

[0079] A base end 47c of the reflecting surface 47a is connected to the rear surface 42. Therefore, it can be said that the base end 47c of the reflecting surface 47a is connected to the main surface 31 of the waveguide 30 (the inner surface of the through hole 37) via the second adhesive layer AH2. The position of the base end 47c of the reflecting surface 47a in a direction perpendicular to the z direction is the same as the periphery of the opening of the through hole 37 of the waveguide 30 in the main surface 31 when viewed from the z direction, or is located outward from the periphery of the opening.

[0080] 4, the electromagnetic wave emitted from radiation point P2 of terahertz element 50 in the z direction toward reflector 47 is transmitted as a spherical wave through transmission region 38 and reflected by reflecting surface 47a in one direction (toward device side surface 13) that intersects with the radiation direction (z direction) of the electromagnetic wave from terahertz element 50. The electromagnetic wave reflected by reflecting surface 47a changes from a spherical wave to a plane wave and is emitted from device opening 17 to the outside of terahertz device 10.

[0081] 9 and 10, the reflector 40 has a bonding portion 48 for bonding to the waveguide 30 via a second adhesive layer AH2. The bonding portion 48 is a portion that includes the rear surface 42 of the reflector 40, and has an inner surface 48a that is connected to the reflecting surface 47a. As shown in FIG. 9, the inner surface 48a is formed in a curved shape. As shown in FIG. 10, the inner surface 48a is formed in a tapered shape that increases in diameter from the rear surface 42 toward the main surface 41 of the reflector 40. When viewed from the z direction, the inner surface 48a is located at the same position as the periphery of the opening of the through hole 37 of the waveguide 30 in the main surface 31, or is located outward from the periphery in a direction perpendicular to the z direction.

[0082] (action) The operation of the terahertz device 10 of this embodiment will be described with reference to Fig. 4 and Fig. 11. Fig. 11 is a cross-sectional view showing the cross-sectional structure of a terahertz device 10X of a comparative example taken along a plane along the z direction and the x direction.

[0083] As shown in FIG. 11, the terahertz device 10X includes an antenna base 200, a support substrate 210, and a terahertz element 50 mounted on the support substrate 210. The antenna base 200 is made of a conductive material that is non-transparent to electromagnetic waves, such as Cu or Al. The antenna base 200 has a base main surface 201 and a base back surface 202 that face opposite each other in the z direction, and four base side surfaces 203 that are located between the base main surface 201 and the base back surface 202 and are perpendicular to the base main surface 201 and the base back surface 202.

[0084] The antenna base 200 is formed with a spherical recess 204 that is recessed in a spherical shape from the base main surface 201 toward the base back surface 202. The surface of the spherical recess 204 forms a reflecting surface 205 that reflects electromagnetic waves.

[0085] The support substrate 210 is formed, for example, in the shape of a rectangular plate, and is attached to the base main surface 201 of the antenna base 200 via an adhesive layer 220. The support substrate 210 has a substrate main surface 211 and a substrate back surface 212 that face opposite each other in the z direction. The substrate main surface 211 faces the same side as the base main surface 201, and the substrate back surface 212 faces the same side as the base back surface 202. The support substrate 210 protrudes from one side in the x direction relative to the base side surface 203.

[0086] The support substrate 210 is made of a material that is transparent to electromagnetic waves. The terahertz element 50 is mounted on the rear surface 212 of the substrate. The terahertz element 50 is mounted on the substrate back surface 212 so that the element main surface 51 faces the same side as the substrate back surface 212, and the element back surface 52 faces the same side as the substrate main surface 211. As shown in Fig. 11 , the terahertz element 50 is disposed in the spherical recess 204 of the antenna base 200. The terahertz element 50, which oscillates and emits electromagnetic waves in the terahertz band, emits the electromagnetic waves toward the spherical recess 204.

[0087] A power feed line 213 is formed on the back surface 212 of the support substrate 210. The power feed line 213 is made of, for example, Cu. That is, the power feed line 213 is made of a conductive material that is non-transparent to electromagnetic waves. The power feed line 213 protrudes from one side in the x-direction beyond the base side surface 203 and is connected to an exterior terminal or connector (not shown).

[0088] In the terahertz device 10X of the comparative example, when electromagnetic waves are emitted from the terahertz element 50, the emitted electromagnetic waves are reflected by the reflecting surface 205 and emitted to the outside of the terahertz device 10X as electromagnetic waves propagating along the z direction, thereby making it possible to give the electromagnetic waves directionality.

[0089] In the terahertz device 10X of the comparative example, when the electromagnetic waves emitted from the terahertz element 50 are reflected by the reflecting surface 205, a part of the reflected electromagnetic waves may hit the power supply line 213 and not be emitted to the outside of the terahertz device 10X. In this way, since the power supply line 213 is arranged on the path along which the electromagnetic waves are emitted from the inside of the terahertz device 10X to the outside, the electromagnetic waves are blocked by the power supply line 213.

[0090] To address this problem, in this embodiment, as shown in FIG. 4 , the terahertz element 50 is mounted on the substrate main surface 21 of the support substrate 20 on which the power feed line 27 is formed. Therefore, the element main surface 51 of the terahertz element 50 is disposed closer to the reflector 40 in the z direction than the power feed line 27. In other words, the power feed line 27 is disposed on the side of the element main surface 51 of the terahertz element 50 opposite to the emission direction of the electromagnetic wave. In other words, the power feed line 27 is not disposed on the path along which the electromagnetic wave is emitted from the inside of the terahertz device 10 to the outside. As a result, the power feed line 27 is not disposed on the path along which the electromagnetic wave is emitted from the inside of the terahertz device 10 to the outside, and therefore, it is possible to avoid the electromagnetic wave being blocked by the power feed line 27.

[0091] The terahertz device 10 also includes a reflector 40 having a reflecting surface 47a that covers the element principal surface 51 of the terahertz element 50 from the z direction. It can be said that the reflecting surface 47a covers the element principal surface 51 of the terahertz element 50 from the emission direction of the electromagnetic wave from the terahertz element 50. Therefore, the electromagnetic wave radiated from the terahertz element 50 is reflected by the reflecting surface 47a and emitted to the outside of the terahertz device 10 in a direction perpendicular to the z direction. In this way, the directivity of the electromagnetic wave can be increased in a direction intersecting the thickness direction of the terahertz element 50.

[0092] (effect) The terahertz device 10 of this embodiment provides the following effects. (1-1) The terahertz device 10 includes a terahertz element 50 and a reflector 40. The terahertz element 50 has an element main surface 51 and an element back surface 52 facing the opposite side to the element main surface 51, and is an element that emits electromagnetic waves in the terahertz band. The reflector 40 has a reflecting surface 47a. The reflecting surface 47a is disposed at a position facing the element main surface 51 with an interval in the z direction, and reflects the electromagnetic waves emitted by the terahertz element 50 in a direction intersecting the thickness direction (z direction) of the terahertz element 50.

[0093] According to this configuration, the reflecting surface 47a of the reflector 40 faces the element main surface 51 at an interval in the radiation direction of the electromagnetic wave from the terahertz element 50. Therefore, the electromagnetic wave radiated from the terahertz element 50 in the thickness direction of the terahertz element 50 (z direction) is reflected by the reflecting surface 47a and propagates in a direction intersecting the thickness direction of the terahertz element 50 (y direction in this embodiment). This makes it possible to increase the directivity of the electromagnetic wave in the direction intersecting the thickness direction of the terahertz element 50. Therefore, it is possible to improve the antenna gain.

[0094] (1-2) The terahertz device 10 includes a support substrate 20 having a substrate main surface 21. The terahertz element 50 is mounted on the substrate main surface 21 such that the element main surface 51 faces the same side as the substrate main surface 21. A power supply line 27 electrically connected to the terahertz element 50 is provided on the substrate main surface 21.

[0095] According to this configuration, since the feed line 27 is disposed on the opposite side of the element principal surface 51 of the terahertz element 50 from the direction in which the electromagnetic waves are radiated, it is possible to prevent the electromagnetic waves radiated from the element principal surface 51 of the terahertz element 50 from being blocked by the feed line 27. In this way, according to the terahertz device 10 of the present embodiment, it is possible to improve the antenna gain while avoiding blocking by the feed line 27.

[0096] (1-3) The terahertz element 50 has an oscillation point P1 that oscillates electromagnetic waves and a radiation point P2 that radiates electromagnetic waves on the element principal surface 51. According to this configuration, the terahertz element 50 is disposed within the transmission region 38, and therefore both the oscillation point P1 and the radiation point P2 are disposed within the transmission region 38. Therefore, compared to a configuration in which an electromagnetic wave is emitted by transmitting a high-frequency signal from an oscillation element disposed outside the transmission region 38 to an antenna disposed within the transmission region via a transmission line, the terahertz device 10 can obtain high coupling between the terahertz element 50 and the waveguide 30.

[0097] (1-4) The shape of the reflecting surface 47a of the reflector 40 is such that y=z 2 / 4f, where f is the distance in the z direction between base end 47c of reflecting surface 47a and radiation point P2 of terahertz element 50 in the y direction. With this configuration, the electromagnetic waves radiated from terahertz element 50 are reflected by reflecting surface 47a in a direction intersecting the thickness direction of terahertz element 50, and therefore, the directivity of the electromagnetic waves in the direction intersecting the thickness direction of terahertz element 50 can be increased.

[0098] (1-5) Reflecting surface 47a of reflector 40 is formed of a paraboloid of revolution. With this configuration, the electromagnetic wave radiated from terahertz element 50 is reflected by reflecting surface 47a in a direction intersecting the thickness direction of terahertz element 50, thereby increasing the directivity of the electromagnetic wave in the direction intersecting the thickness direction of terahertz element 50.

[0099] (1-6) The terahertz device 10 includes a waveguide 30 having a transmission region 38 that transmits electromagnetic waves. The terahertz element 50 is disposed within the transmission region 38. The reflector 40 is provided on the waveguide 30 on the side opposite to the side on which the support substrate 20 is disposed with respect to the waveguide 30. With this configuration, all of the electromagnetic waves radiated from the terahertz element 50 toward the reflector 40 are directed by the waveguide 30 toward the reflecting surface 47a of the reflector 40, thereby achieving a high antenna gain.

[0100] (1-7) Reflector 40 is provided separately from waveguide 30. According to this configuration, reflector 40 can be attached to the waveguide of an existing terahertz device that includes, for example, a support substrate, a terahertz element mounted on the support substrate, and a waveguide having a transmission region that accommodates the terahertz element.

[0101] (1-8) When viewed from the z direction, the reflecting surface 47a of the reflector 40 covers the entire through-hole 37 of the waveguide 30. This configuration increases the probability that the electromagnetic waves from the terahertz element 50 passing through the transmission region 38 formed in the through-hole 37 will be reflected by the reflecting surface 47a. This increases the directivity of the electromagnetic waves emitted from the terahertz device 10 through the device opening 17 in a direction intersecting the thickness direction of the terahertz element 50, thereby improving the antenna gain.

[0102] (1-9) The tip 47b of the reflecting surface 47a of the reflector 40 is provided at a position intersecting with the imaginary line LV extending from the tapered surface 37a of the through-hole 37 of the waveguide 30. This configuration further increases the probability that the electromagnetic waves from the terahertz element 50 passing through the transmission region 38 formed in the through-hole 37 will be reflected by the reflecting surface 47a. Therefore, it is possible to further increase the directivity of the electromagnetic waves emitted from the terahertz device 10 through the device opening 17 in a direction intersecting the thickness direction of the terahertz element 50, thereby further improving the antenna gain.

[0103] (1-10) An exterior terminal 28 electrically connected to the terahertz element 50 is provided on the rear surface 22 of the support substrate 20. With this configuration, when the terahertz device 10 is mounted on a circuit board, the terahertz device 10 can be flip-chip mounted on the circuit board.

[0104] (1-11) The terahertz element 50 is disposed so that the radiation point P2 is located at the center of the transmission region 38. With this configuration, it becomes easier for the terahertz element 50 to directly radiate electromagnetic waves into the transmission region 38 of the waveguide 30, and high coupling is achieved between the waveguide 30 and the terahertz element 50.

[0105] (1-12) Terahertz element 50 has element principal surface 51 and element rear surface 52, and has a radiation pattern that radiates electromagnetic waves in a direction perpendicular to element principal surface 51 and element rear surface 52. Terahertz element 50 is disposed with respect to waveguide 30 so that the radiation direction of the electromagnetic waves from terahertz element 50 is parallel to central axis J of waveguide 30. With this configuration, terahertz element 50 can be efficiently coupled to waveguide 30.

[0106] (1-13) When viewed from the z direction, the rear surface 42 of the reflector 40 is located at the same position as the inner surface that forms the opening of the main surface 31 of the through-hole 37 of the waveguide 30, or is located further outward than the inner surface. This configuration makes it possible to prevent the electromagnetic waves radiated from the terahertz element 50 from being reflected by the rear surface 42 of the reflector 40. Therefore, the electromagnetic waves radiated from the terahertz element 50 can easily propagate toward the reflecting surface 47a.

[0107] (1-14) The reflector 40 is made of a conductive material that is non-transparent to electromagnetic waves. With this configuration, the function of reflecting the electromagnetic waves from the terahertz element 50 can be achieved by a single component, the reflector 40.

[0108] (1-15) The inner surface 48a of the joint 48 of the reflector 40 is a curved surface whose diameter increases from the back surface 42 toward the main surface 41 of the reflector 40. This configuration can prevent the electromagnetic wave from the terahertz element 50 from impinging on the inner surface 48a of the joint 48. This prevents the electromagnetic wave from being reflected on the inner surface 48a and impinging on the reflecting surface 47a at an unexpected angle of incidence, making it easier for the electromagnetic wave from the terahertz element 50 to be reflected on the reflecting surface 47a and become a plane wave that propagates from the device opening 17 in the y direction.

[0109] [Second embodiment] 12 to 17, a terahertz device 10 according to a second embodiment will be described. The terahertz device 10 according to this embodiment differs from the terahertz device 10 according to the first embodiment mainly in the mounting configuration of the reflector 40 and the waveguide 30. In the following description, details of the parts that differ from the first embodiment will be described, and the same reference numerals will be used to designate the same components as those of the terahertz device 10 according to the first embodiment, and descriptions thereof will be omitted.

[0110] As shown in Figures 12 and 13, in this embodiment, the reflector 40 is detachably attached to the waveguide 30. The reflector 40 of this embodiment has a configuration in which an attachment portion 49 for detachably attaching the reflector 40 to the waveguide 30 is added to the reflector 40 of the first embodiment. Therefore, the reflector 40 of this embodiment includes a reflecting portion 47 and the attachment portion 49. In this embodiment, the reflector 40 is a single component in which the reflecting portion 47 and the attachment portion 49 are integrally formed. In other words, in this embodiment, the second adhesive layer AH2 is not interposed between the attachment portion 49 and the waveguide 30.

[0111] The attachment portion 49 is provided on the rear surface 42 side of the reflector 40 with respect to the reflecting portion 47. Therefore, the attachment portion 49 includes the rear surface 42 of the reflector 40. The attachment portion 49 extends in the z direction from the base end portion 47c of the reflecting surface 47a.

[0112] The mounting portion 49 has a first mounting portion 49A and a second mounting portion 49B. The first mounting portion 49A is a portion that includes the back surface 42 of the reflector 40. The second mounting portion 49B is a portion between the first mounting portion 49A and the reflecting surface 47a in the z direction.

[0113] 13, the first mounting portion 49A is formed in a generally rectangular frame shape that surrounds the waveguide 30 in the x and y directions and is partially cut by a slit 49a extending in the z direction. In this embodiment, the slit 49a is provided in a portion of the first mounting portion 49A that is spaced apart in the y direction from the base end 47c of the reflecting surface 47a. The slit 49a penetrates the first mounting portion 49A in both the z and y directions.

[0114] Opening 49b of first mounting portion 49A penetrates first mounting portion 49A in the z direction and is configured to allow insertion of waveguide 30. As shown in Fig. 14, the distance between a pair of inner surfaces 49c of opening 49b facing each other in the x direction, in other words, the size of opening 49b in the x direction, is equal to the distance between tube side surface 35 and tube side surface 36 of waveguide 30 (both see Fig. 3), in other words, the size of waveguide 30 in the x direction. The distance between a pair of inner surfaces 49d of opening 49b facing each other in the y direction, in other words, the size of opening 49b in the y direction, is equal to the distance between tube side surface 33 and tube side surface 34 of waveguide 30 (both see Fig. 3), in other words, the size of waveguide 30 in the y direction. Here, the expression "the size in the x direction of opening 49b is equal to the size in the x direction of waveguide 30" includes the relationship between the size in the x direction of opening 49b, which results in an intermediate fit or an interference fit, and the size in the x direction of waveguide 30, on the assumption that waveguide 30 is insertable into mounting portion 49. Furthermore, the expression "the size in the y direction of opening 49b is equal to the size in the y direction of waveguide 30" includes the relationship between the size in the y direction of opening 49b, which results in an intermediate fit or an interference fit, and the size in the y direction of waveguide 30, on the assumption that waveguide 30 is insertable into mounting portion 49.

[0115] 14 and 15, the reflector 40 has a step portion 49S provided at the boundary between the first mounting portion 49A and the second mounting portion 49B. As shown in FIG. 15, the step portion 49S is constituted by an inner surface 49d of the mounting portion 49 and an end face 49r of the second mounting portion 49B on the mounting portion 49 side in the z direction. This end face 49r protrudes inward beyond the inner surfaces 49c, 49d of the opening 49b. As shown in FIG. 14, the end face 49r has an inner edge that is semicircular when viewed from the z direction. The diameter of the inner edge of the end face 49r is equal to the diameter of the through hole 37 (see FIG. 13) of the waveguide 30.

[0116] The second mounting portion 49B has an inclined surface 49e that connects to the reflecting surface 47a. When viewed from the z direction, the second mounting portion 49B is provided so as to surround the reflecting surface 47a from both sides in the x direction and one side in the y direction. The inclined surface 49e is a curved surface that increases in diameter from the back surface 42 of the reflector 40 toward the main surface 41.

[0117] 15, a portion of inclined surface 49e close to side surface 44 is inclined toward side surface 44 as it moves away from first mounting portion 49A in the z direction. The portion of inclined surface 49e close to side surface 44 is connected to base end portion 47c of reflecting surface 47a. As shown in Fig. 16, both ends of inclined surface 49e in the x direction are inclined so as to move away from first mounting portion 49A in the z direction.

[0118] 12 , in this embodiment, the inclination angle of inclined surface 49e with respect to end face 49r of step portion 49S is set to be smaller than the inclination angle of the inner surface that constitutes through hole 37 of waveguide 30 with respect to tube main surface 31. Note that the inclination angle of inclined surface 49e with respect to end face 49r of step portion 49S may be set to be equal to the inclination angle of the inner surface that constitutes through hole 37 of waveguide 30 with respect to tube main surface 31.

[0119] Since the second mounting portion 49B is provided closer to the main surface 41 of the reflector 40 than the step portion 49S, the reflecting portion 47 is provided in the z direction at a distance from the step portion 49S and closer to the main surface 41 than the step portion 49S.

[0120] 17, in a state in which the reflector 40 is attached to the waveguide 30, the step portion 49S is in contact with the main surface 31 of the waveguide 30. More specifically, an end face 49r constituting the step portion 49S is in contact with the main surface 31 of the waveguide 30 in the z direction. When viewed from the z direction, the inner edge of this end face 49r is positioned outward in a direction perpendicular to the z direction from the inner edge constituting the portion of the through hole 37 of the waveguide 30 that opens into the main surface 31.

[0121] The position of the inner edge of the end face 49r of the step portion 49S can be changed as desired. In one example, the inner edge of the end face 49r may be aligned in a direction perpendicular to the z direction with respect to the inner edge of the portion of the through hole 37 of the waveguide 30 that opens to the tube main surface 31, as viewed from the z direction. In addition, in this embodiment, the tube main surface 31 is in contact with the end face 49r of the step portion 49S that is formed closer to the main surface 41 than the back surface 42, so that the tube main surface 31 is positioned closer to the main surface 41 than the back surface 42 of the reflector 40.

[0122] The reflecting section 47 of this embodiment has the same configuration as the reflecting section 47 of the first embodiment. In this embodiment, the tip 47b of the reflecting surface 47a defines the opening 40A of the reflector 40, and it can be said that the device opening 17 is defined by the tip 47b and the main surface 31 of the waveguide 30. In other words, it can be said that the device opening 17 is the area between the tip 47b and the main surface 31 of the waveguide 30. Because the reflector 40 of this embodiment has an attachment section 49, the device opening 17 of this embodiment is larger than the device opening 17 of the first embodiment.

[0123] In this embodiment, the reflecting surface 47a is spaced apart in the z direction from the main surface 31 of the waveguide 30. More specifically, an inclined surface 49e is disposed between the reflecting surface 47a and the main surface 31.

[0124] As shown in FIGS. 15 to 17, the reflecting portion 47 is formed as a curved concave surface that curves from the side surface 44 to the side surface 43 as it moves from the rear surface 42 to the main surface 41, similar to the first embodiment.

[0125] When the reflecting surface 47a of the reflecting portion 47 is formed by an aspherical surface, for example, in the cross section of the reflector 40 shown in FIG. 17, the reflecting surface 47a of the reflecting portion 47 is formed by an aspherical surface, as in the first embodiment, in the cross section of the reflector 40 shown in FIG. 2 / 4f, where y is the coordinate in the y direction and z is the coordinate in the z direction. f is the distance in the y direction between the portion of reflecting surface 47a closest to device side surface 14 and radiation point P2 of terahertz element 50. In this embodiment, as in the first embodiment, reflecting surface 47a is formed as a paraboloid of revolution.

[0126] 17, reflecting surface 47a is provided so as to cover terahertz element 50 from the z direction. More specifically, reflecting surface 47a is provided so as to cover transmission region 38 from the z direction. When viewed from the z direction, reflecting surface 47a covers the entire area extending in the z direction from tapered surface 37a of waveguide 30 along tapered surface 37a. In this embodiment, as shown in FIG. 17, tip end 47b of reflecting surface 47a extends from a portion of tapered surface 37a of through-hole 37 of waveguide 30 that corresponds to tube-side surface 33 to a position where it intersects with an imaginary line LV extending in the z direction along tapered surface 37a.

[0127] The electromagnetic wave emitted from radiation point P2 of terahertz element 50 is transmitted as a spherical wave through transmission region 38 and reflected in one direction (toward device side surface 13) by reflecting surface 47a. That is, the electromagnetic wave emitted from terahertz element 50 is reflected by reflecting surface 47a toward device opening 17. The electromagnetic wave reflected by reflecting surface 47a changes from a spherical wave to a plane wave and is emitted from device opening 17 to the outside of terahertz device 10.

[0128] (effect) According to the terahertz device 10 of this embodiment, the following effects can be obtained in addition to the effects of the first embodiment.

[0129] (2-1) The reflector 40 is detachably attached to the waveguide 30. With this configuration, the attachment direction of the reflector 40 relative to the waveguide 30 in the x direction or y direction can be changed. In other words, the position of the device opening 17 of the terahertz device 10 can be changed even after the reflector 40 is attached to the waveguide 30.

[0130] (2-2) The reflector 40 has a step portion 49S. When the reflector 40 is attached to the waveguide 30, the step portion 49S contacts the main surface 31 of the waveguide 30 in the z direction. With this configuration, the position of the reflector 40 in the z direction relative to the waveguide 30 can be easily determined. Therefore, the reflector 40 can be easily attached to the waveguide 30.

[0131] (2-3) Mounting portion 49 of reflector 40 has slit 49a penetrating mounting portion 49 in the z direction. With this configuration, even if there is variation in the outer dimensions of waveguide 30 or the dimensions of opening 49b of mounting portion 49, slit 49a increases the dimensions of opening 49b of mounting portion 49, making it easy to insert reflector 40 into waveguide 30.

[0132] (2-4) When viewed from the z direction, the inner surface of the opening 49b of the mounting portion 49 is located at the same position as the inner surface of the through-hole 37 of the waveguide 30 that forms the opening of the main surface 31, or is located further outward than the inner surface. This configuration makes it possible to prevent the electromagnetic waves radiated from the terahertz element 50 from being reflected by the opening 49b of the mounting portion 49. Therefore, the electromagnetic waves radiated from the terahertz element 50 can easily propagate toward the reflecting surface 47a.

[0133] [Third embodiment] A terahertz device 10 according to a third embodiment will be described with reference to FIGS. 18, the terahertz device 10 of this embodiment includes a support substrate 80, a plurality of (64 in this embodiment) terahertz elements 50 mounted on the support substrate 80, and a reflector 90 covering each of the terahertz elements 50. For convenience, some of the plurality of terahertz elements 50 and a power supply line 88, which will be described later and is formed on the support substrate 80, are omitted from the illustration in FIG.

[0134] The support substrate 80 is made of an electrically insulating material, such as a glass epoxy substrate. The support substrate 80 is formed in the shape of a rectangular flat plate. The support substrate 80 has a substrate main surface 81 and a substrate back surface 82 that face opposite each other in its thickness direction (z direction), and substrate side surfaces 83 to 86 that are located between the substrate main surface 81 and the substrate back surface 82 in the z direction and intersect with the substrate main surface 81 and the substrate back surface 82. In this embodiment, each of the substrate side surfaces 83 to 86 is perpendicular to the substrate main surface 81 and the substrate back surface 82.

[0135] When viewed from the z direction, the substrate main surface 81 and the substrate back surface 82 have the same shape. When viewed from the z direction, the shape of the substrate main surface 81 is a rectangle with the long side direction being the x direction and the short side direction being the y direction. However, when viewed from the z direction, the substrate main surface 81 and the substrate back surface 82 may have different shapes.

[0136] 19, the substrate side surfaces 83 and 84 are surfaces facing opposite each other in the y direction. Each of the substrate side surfaces 83 and 84 extends along the x direction when viewed from the z direction. The substrate side surfaces 85 and 86 are surfaces facing opposite each other in the x direction. Each of the substrate side surfaces 85 and 86 extends along the y direction when viewed from the z direction.

[0137] 19, the support substrate 80 is provided with a plurality of (four in this embodiment) mounting holes 87 for mounting the reflector 90. Each mounting hole 87 is a through-hole that penetrates the support substrate 80 in the z direction. In this embodiment, the plurality of mounting holes 87 are provided two at each end of the support substrate 80 in the x direction.

[0138] 19, a power supply line 88 is formed on the substrate main surface 81. The power supply line 88 has a plurality of (64 in this embodiment) main conductors 88A electrically connected to the first pad electrode 63c (see FIG. 8) of the terahertz element 50, a plurality of (64 in this embodiment) pads 88B on which the terahertz element 50 (see FIG. 18) is mounted, and a ground conductor 88C electrically connected to the second pad electrode 64c (see FIG. 8) of the terahertz element 50.

[0139] The number of main conductors 88A and the number of pads 88B are set according to the number of terahertz elements 50. Each pad 88B is arranged on the substrate main surface 81 closer to the substrate side surface 84 than to the center of the substrate main surface 81 in the y direction. The multiple pads 88B are arranged aligned with each other in the y direction but spaced apart from each other in the x direction. In other words, the multiple pads 88B are arranged in a line along the x direction.

[0140] Each main conductor 88A extends along the y direction. When viewed from the z direction, the multiple main conductors 88A are arranged with a gap between them in the y direction while being aligned with the multiple pads 88B in the x direction. Each main conductor 88A is disposed closer to the substrate side surface 84 than the pads 88B. Of both ends of each main conductor 88A in the y direction, a connection land 88a is formed on the end closer to the substrate side surface 83. In this embodiment, the length in the x direction of the connection land 88a is longer than the length in the x direction of the portion of the main conductor 88A other than the connection land 88a. Therefore, when two main conductors 88A adjacent to each other in the x direction are considered to be a set of main conductors 88A, the set of main conductors 88A is formed so that the connection lands 88a of the set of main conductors 88A are aligned with each other in the x direction while being spaced apart from each other in the y direction.

[0141] The connection land portions 88a are formed, for example, in a circular shape. Although not shown, through holes (penetrating holes) are provided in the support substrate 80 so as to penetrate each connection land portion 88a and the support substrate 80 in the z direction.

[0142] The ground conductor 88C is provided as a common conductor for the multiple terahertz elements 50. The ground conductor 88C is formed in a substantially U-shape when viewed from the z direction so as to surround the multiple main conductors 88A and the multiple pads 88B on both sides in the x direction and from the substrate side surface 84 side in the y direction.

[0143] The ground conductor 88C has a first conductor portion 88p and a second conductor portion 88q that extend along the y direction, and a connecting conductor portion 88r that connects the first conductor portion 88p and the second conductor portion 88q in the x direction.

[0144] The first conductor portion 88p is disposed closer to the substrate side surface 85 in the x direction than the main conductors 88A and the pads 88B. The second conductor portion 88q is disposed closer to the substrate side surface 86 in the x direction than the main conductors 88A and the pads 88B.

[0145] Two connection lands 88b are formed on the end of each of the conductors 88p, 88q in the y direction that is closer to the substrate side surface 83. The two connection lands 88b are aligned with each other in the x direction and spaced apart from each other in the y direction. In this embodiment, the connection land 88b and the connection land 88a are aligned with each other in the x direction. In this embodiment, the length of the connection land 88b in the x direction is longer than the length of each of the conductors 88p, 88q in the x direction.

[0146] Each connection land portion 88b is formed, for example, in a circular shape. Although not shown, through holes are provided in the support substrate 80 so as to penetrate each connection land portion 88b and the support substrate 80 in the z direction.

[0147] The connecting conductor 88r is disposed closer to the substrate side surface 84 in the y direction than the main conductors 88A and the pads 88B. The connecting conductor 88r is disposed adjacent to each pad 88B in the y direction and extends along the x direction. The connecting conductor 88r connects the ends of the conductors 88p, 88q in the y direction that are closer to the substrate side surface 84.

[0148] Although not shown, a pin header is inserted into a through hole formed in the support substrate 80 from the rear surface 82 side of the substrate. The pin header is connected to each connection land portion 88a, 88b on the main surface 81 of the substrate by a conductive bonding material such as solder. A connector is connected to the pin header on the rear surface 82 side of the substrate for transmitting and receiving (supplying or outputting) a high-frequency signal to the terahertz element 50. Note that instead of the pin header, a surface-mounted connector may be mounted on the rear surface 82 of the substrate.

[0149] 20, the terahertz element 50 is mounted on a pad 88B. More specifically, the terahertz element 50 is bonded to the pad 88B by, for example, a conductive bonding material. That is, the terahertz element 50 is die-bonded to the pad 88B. The multiple terahertz elements 50 mounted on the multiple pads 88B are aligned with each other in the y direction and spaced apart from each other in the x direction. That is, the multiple terahertz elements 50 are aligned in a uniform array along the x direction.

[0150] Each terahertz element 50 is mounted on each pad 88B so that the element main surface 51 faces the same side as the substrate main surface 81 and the element back surface 52 faces the same side as the substrate back surface 82. The configuration of each terahertz element 50 is the same as the configuration of the terahertz element 50 of the first embodiment. Therefore, each terahertz element 50 radiates electromagnetic waves along the z direction.

[0151] Each terahertz element 50 and each main conductor 88A are connected by a first wire W1. The first wire W1 is connected to a first pad electrode 63c (see FIG. 8) of the terahertz element 50. The first wire W1 is also connected to one of both ends of the main conductor 88A in the y direction that is closer to the terahertz element 50. This electrically connects the first pad electrode 63c of the terahertz element 50 and the main conductor 88A.

[0152] Each terahertz element 50 and the ground conductor 88C are connected by a second wire W2. Each second wire W2 is connected to the second pad electrode 64c (see FIG. 8) of each terahertz element 50. Each second wire W2 is also connected to the linking conductor portion 88r of the ground conductor 88C. This electrically connects the second pad electrode 64c of each terahertz element 50 and the ground conductor 88C.

[0153] As shown in FIG. 18 , the reflector 90 is attached to the substrate main surface 81 of the support substrate 80 with a plurality of (four in this embodiment) screws SC and nuts (not shown). The reflector 90 is a component that reflects the electromagnetic waves from the terahertz element 50 in a direction intersecting the z direction. More specifically, the reflector 90 is a reflective member that reflects the electromagnetic waves transmitted from the terahertz element 50 via the waveguide 30 in a predetermined direction. The reflector 90 is configured as, for example, a horn reflector antenna. The reflector 90 is made of a conductive material that is non-transparent to the electromagnetic waves emitted by the terahertz element 50. Metallic materials such as Cu, Cu alloys, Al, and Al alloys can be used as this material. The reflector 90 can also be said to be made of a metallic material.

[0154] The reflector 90 has an opening 97 that is open on one side in the y direction, which is the one direction. More specifically, the opening 97 is open toward the substrate side surface 83. Therefore, it can be said that the opening 97 is open in a direction intersecting the thickness direction of the terahertz element 50. More specifically, it can be said that the opening 97 is open in a direction perpendicular to the thickness direction of the terahertz element 50.

[0155] When the reflector 90 is attached to the support substrate 80, the terahertz device 10 can be said to have a device opening 17. The device opening 17 can also be said to open in a direction intersecting the thickness direction of the terahertz element 50. In this embodiment, the device opening 17 opens in a direction perpendicular to the thickness direction of the terahertz element 50. The device opening 17 is defined by the reflector 90 and the support substrate 80. The device opening 17 can be said to be an emission portion through which electromagnetic waves from the terahertz element 50 are emitted when the terahertz element 50 oscillates. The device opening 17 only needs to have a portion facing the terahertz element 50 in the thickness direction of the terahertz element 50 that is not open in the thickness direction of the terahertz element 50. In other words, the device opening 17 only needs to be configured so that electromagnetic waves emitted by the terahertz element 50 in the z direction and reflected by the reflecting surface 47a can be emitted to the outside of the terahertz device 10 in the propagation direction of the electromagnetic waves.

[0156] The reflector 90 is formed so as to cover all of the terahertz elements 50 in the z direction. The reflector 90 has a main surface 91 and a back surface 92 (see FIG. 20 ) facing opposite sides in the z direction, and side surfaces 93 to 96 that are located between the main surface 91 and the back surface 92 in the z direction and intersect with the main surface 91 and the back surface 92.

[0157] The main surface 91 faces the same side as the substrate main surface 81, and the back surface 92 faces the same side as the substrate back surface 82. Therefore, the reflector 90 is disposed on the support substrate 80 with the back surface 92 in contact with the substrate main surface 81.

[0158] The side surface 93 faces the same side as the substrate side surface 83, the side surface 94 faces the same side as the substrate side surface 84, the side surface 95 faces the same side as the substrate side surface 85, and the side surface 96 faces the same side as the substrate side surface 86. The side surfaces 94 to 96 are formed from the back surface 92 to the main surface 91 of the reflector 90. The side surface 93 is formed away from the back surface 92 in the z direction. The side surface 93 is disposed closer to the main surface 91 than the back surface 92 in the z direction.

[0159] The reflector 90 has a reflecting portion 90A and an attachment portion 90B. In this embodiment, the reflector 90 is a single component in which the reflecting portion 90A and the attachment portion 90B are integrally formed. 20 , the reflecting portion 90A is formed with a reflecting surface 98 that reflects electromagnetic waves emitted by the terahertz element 50 in the z direction in a direction intersecting the z direction. In this embodiment, the reflecting surface 98 is a curved concave surface that curves in the z direction from the back surface 92 toward the main surface 91 and toward the side surface 93. The curved shape of the reflecting surface 98 may be formed into a shape similar to the curved shape of the reflecting surface 47a in the first embodiment, for example.

[0160] Here, the end of the reflecting surface 98 that is closer to the side surface 93 of the reflector 90 is referred to as a tip end 98a, and the end of the reflecting surface 98 that is closer to the back surface 92 of the reflector 90 is referred to as a base end 98b. In this embodiment, the tip end 98a defines an opening 97 of the reflector 90, and it can be said that the device opening 17 is defined by the tip end 98a and the substrate main surface 81 of the support substrate 80. In other words, it can be said that the device opening 17 is the region between the tip end 98a and the substrate main surface 81 of the support substrate 80.

[0161] Furthermore, a vertical surface 99 is formed on the reflecting portion 90A. The vertical surface 99 is a surface that connects a base end portion 98b of the reflecting surface 98 and the back surface 92, and is a plane that extends along the z direction and the x direction. In other words, the reflecting surface 98 is formed away from the back surface 92 of the reflector 90 in the z direction. Therefore, the reflecting surface 98 is disposed away from the substrate main surface 81 of the support substrate 80 in the z direction.

[0162] As shown in Figure 20, in this embodiment, in the z direction, the end (base end 98b) of the reflecting surface 98 that is closer to the vertical surface 99 is located closer to the main surface 91 of the reflector 90 than the element main surface 51 of the terahertz element 50.

[0163] As shown in FIG. 18 , when viewed from the z direction, the mounting portions 90B are provided so as to protrude in the x direction from each of side surfaces 95, 96 on both sides of the reflector 90 in the x direction. The mounting portions 90B are formed in a strip shape extending in the y direction. Each mounting portion 90B is provided with an insertion hole (not shown) through which a screw SC is inserted. The insertion hole passes through each mounting portion 90B in the z direction. The screw SC is also inserted into a mounting hole 87 shown in FIG. 19 . The reflector 90 is attached to the support substrate 80 by sandwiching the mounting portion 90B and the support substrate 80 between the screw head of the screw SC and a nut (not shown) on the back surface 82 side of the support substrate 80.

[0164] As shown in FIG. 20, the terahertz element 50 is disposed closer to the substrate side surface 84 in the y direction than the center of the reflecting surface 98 of the reflector 90 in the y direction. The connecting conductor portion 88r of the ground conductor 88C, which is disposed closer to the substrate side surface 84 in the y direction than the terahertz element 50, is disposed at a position that overlaps with the reflecting surface 98 when viewed from the z direction.

[0165] In addition, in this embodiment, of the connection land portion 88a of the main conductor 88A and the connection land portion 88b of the ground conductor 88C, the connection land portions 88a, 88b that are arranged near the substrate side surface 83 in the y direction are arranged in positions that do not overlap with the reflector 90 when viewed from the z direction.

[0166] The electromagnetic wave emitted as a spherical wave from the terahertz element 50 toward the reflecting surface 98 is reflected by the reflecting surface 98 toward the opening 97. The electromagnetic wave reflected by the reflecting surface 98 is emitted as a plane wave from the terahertz device 10 through the opening 97 to the outside.

[0167] (effect) The terahertz device 10 of this embodiment provides the following effects. (3-1) In the terahertz device 10, a plurality of terahertz elements 50 are provided, and the reflector 40 is provided so as to cover the element principal surfaces 51 of the plurality of terahertz elements 50 from the z direction. According to this configuration, the reflecting surface 98 of the reflector 90 faces each element principal surface 51 at an interval in the emission direction of the electromagnetic waves of the plurality of terahertz elements 50. Therefore, the electromagnetic waves radiated from each terahertz element 50 are reflected by the reflecting surface 98 and propagate in a direction intersecting the vertical direction (the y direction in this embodiment). Therefore, it is possible to increase the directivity of the electromagnetic waves radiated from each terahertz element 50 at the reflecting surface 98, in other words, the electromagnetic waves in a direction intersecting the thickness direction of the terahertz element 50.

[0168] (3-2) A power supply line 88 electrically connected to the plurality of terahertz elements 50 is formed on the substrate main surface 81 of the support substrate 80. Furthermore, the plurality of terahertz elements 50 are mounted on the substrate main surface 81. With this configuration, it is possible to prevent the electromagnetic waves radiated from the element main surface 51 of the terahertz element 50 from being blocked by the power supply line 88.

[0169] (3-3) The power supply line 88 as a power supply line has a main conductor 88A electrically connected to the first pad electrodes 63c as main electrodes of the multiple terahertz elements 50, and a ground conductor 88C electrically connected to the second pad electrodes 64c as ground electrodes of the multiple terahertz elements 50. The main conductor 88A is provided for each of the multiple terahertz elements 50, and the ground conductor 88C is provided as a conductor common to the multiple terahertz elements 50.

[0170] This configuration can reduce the number of feed lines 88 compared to a configuration in which a ground conductor 88C is provided for each of the terahertz elements 50. This can prevent the support substrate 20 from becoming larger in size due to the formation of the feed lines 88.

[0171] (3-4) Both connection land portion 88a of main conductor 88A and connection land portion 88b of ground conductor 88C are provided at the end of substrate main surface 81 near substrate side surface 83. With this configuration, a common pin header or connector can be connected to main conductor 88A and ground conductor 88C. Signals can then be sent and received to multiple terahertz elements 50 from the substrate rear surface 82 side.

[0172] (3-5) The reflector 90 is made of a conductive material that is non-transparent to electromagnetic waves. With this configuration, the function of reflecting the electromagnetic waves from the terahertz device 50 can be achieved by a single component, the reflector 90.

[0173] (3-6) When viewed from the z direction, a portion of the pin header attached to the support substrate 80 is disposed closer to the substrate side surface 83 than the reflector 90. With this configuration, when the electromagnetic waves radiated from the terahertz element 50 are reflected by the reflecting surface 98, the reflected electromagnetic waves can be prevented from interfering with the pin header. Therefore, a decrease in antenna gain can be suppressed.

[0174] (3-7) The ground conductor 88C is provided to surround the main conductors 88A from both sides in the x direction and one side in the y direction. With this configuration, the ground conductor 88C serves as a wiring shield for the main conductors 88A, thereby preventing noise generated from the main conductors 88A from leaking outside the terahertz device 10.

[0175] [Fourth embodiment] A terahertz device 10 of the fourth embodiment will be described with reference to Figs. 21 to 23. The terahertz device 10 of this embodiment differs from the terahertz device 10 of the first embodiment mainly in that a short-circuit section 130 is added and in the configuration of the waveguide 100. In the following description, details of the parts that differ from the first embodiment will be described, and components that are common to the terahertz device 10 of the first embodiment will be given the same reference numerals and will not be described again. Fig. 22 is a plan view of the terahertz device 10 with the reflector 40 and the antenna section 110 (waveguide 30) and connector 140, which will be described later, omitted.

[0176] 21, the waveguide 100 has an antenna section 110 corresponding to the waveguide 30 of the first embodiment, a main body section 120 joined to the antenna section 110, and a short-circuit section 130 arranged on the opposite side of the main body section 120 from the antenna section 110. The antenna section 110, the main body section 120, and the short-circuit section 130 are formed separately. Since the antenna section 110 has the same configuration as the waveguide 30 of the first embodiment, the components common to the waveguide 30 are denoted by the same reference numerals as the waveguide 30, and their description will be omitted.

[0177] The main body 120 is a component mounted on the substrate main surface 21 of the support substrate 20 and houses the terahertz element 50. The main body 120 is formed in a rectangular parallelepiped shape. When viewed from the z direction, the main body 120 has a rectangular ring shape. The main body 120 is made of a conductive material that is non-transparent to the electromagnetic waves emitted or received by the terahertz element 50. This material can be a metal such as Cu, a Cu alloy, Al, or an Al alloy.

[0178] 21 and 22, the main body portion 120 has a main body main surface 121 and a main body back surface 122 that face opposite each other in the z direction, and main body side surfaces 123 to 126 that are located between the main body main surface 121 and the main body back surface 122 in the z direction and intersect with the main body main surface 121 and the main body back surface 122. In this embodiment, the main body side surfaces 123 to 126 are perpendicular to the main body main surface 121 and the main body back surface 122.

[0179] 21, main body side surface 123 faces the same side as tube side surface 33 of antenna unit 110 (waveguide 30), and main body side surface 124 faces the same side as tube side surface 34 of antenna unit 110. Although not shown, main body side surface 125 faces the same side as tube side surface 35 of antenna unit 110, and main body side surface 126 faces the same side as tube side surface 36 of antenna unit 110.

[0180] As shown in FIGS. 21 and 22 , the main body portion 120 has a through hole 127. The through hole 127 penetrates the main body portion 120 from the main body surface 121 to the main body back surface 122 of the main body portion 120. In other words, the through hole 127 penetrates the main body portion 120 in the z direction (the thickness direction of the main body portion 120). As shown in FIG. 22 , the shape of the through hole 127 when viewed from the z direction is circular. The diameter of the through hole 127 is constant in the z direction. The diameter of the through hole 127 is equal to the minimum value of the diameter of the through hole 37 of the antenna portion 110. The minimum value of the diameter of the through hole 37 is the diameter of the through hole 37 corresponding to the tube back surface 32 of the antenna portion 110.

[0181] The through hole 127 communicates with the through hole 37 of the antenna unit 110. Therefore, like the through hole 37 of the antenna unit 110, the through hole 127 functions as a transmission region 38 that transmits electromagnetic waves.

[0182] The main body 120 also has a groove 128. The groove 128 is formed so as to be recessed from the main body back surface 122 of the main body 120 toward the main body principal surface 121. The groove 128 extends from the main body side surface 123 of the main body 120 to the inner circumferential surface that constitutes the through hole 127. In other words, the groove 128 communicates with the through hole 127. In this embodiment, the shape of the groove 128 when viewed from the y direction is semicircular.

[0183] The groove 128 extends along the main conductor 27a of the power supply line 27 provided on the support substrate 20, which will be described later, and is formed so as to surround the main conductor 27a. Therefore, the main body 120 is not in contact with the main conductor 27a. Note that the shape of the groove 128 as viewed from the x direction is not limited to a semicircular shape, as long as it is not in contact with the main body 120. The shape of the groove 128 as viewed from the x direction can be changed to any shape, such as a square or a triangle.

[0184] A support substrate 20 is attached to the back surface 122 of the main body 120. The support substrate 20 is attached to the back surface 122 of the main body 120 so that the substrate main surface 21 faces the back surface 122 in the z direction. The support substrate 20 and the main body 120 are joined together, for example, with an adhesive. By attaching the support substrate 20 to the main body 120, the through-hole 127 of the main body 120 is closed from the back surface 122 side.

[0185] The support substrate 20 of this embodiment is formed of a material that is transparent to the electromagnetic waves emitted or received by the terahertz element 50. In this embodiment, the support substrate 20 is formed of a dielectric. Examples of the dielectric that can be used include quartz glass, sapphire, rigid resins such as epoxy resin, and single-crystal intrinsic semiconductors such as silicon (Si), and in this embodiment, quartz glass is used. As in the first embodiment, a power feed line 27 is formed on the substrate main surface 21 of the support substrate 20. However, the configuration, arrangement position, and shape of the power feed line 27 differ from those of the power feed line 27 of the first embodiment.

[0186] As shown in FIG. 22, the power supply line 27 of this embodiment has a main conductor 27a and two ground conductors 27b and 27c. The ground conductors 27b and 27c are provided on both sides of the main conductor 27a in the x-direction. The main conductor 27a and the ground conductors 27b and 27c are formed of, for example, Cu. As shown in FIG. 21, the main conductor 27a is connected to a core wire of a connector 140 disposed on the substrate-side surface 23 of the support substrate 20. The connector 140 is capable of transmitting high-frequency signals and is, for example, an SMA (Sub Miniature Type A) connector. The housing of the connector 140 is connected to the main body 120 of the waveguide 30. As shown in FIG. 22, the ground conductors 27b and 27c are in contact with the main body back surface 122 (see FIG. 21) of the main body 120 and are electrically connected to the main body 120. In this way, since the power supply line 27 is connected to the connector 140, the support board 20 of this embodiment does not have an exterior terminal 28 (see Figures 4 and 5) formed on the back surface 22 of the board, unlike the support board 20 of the first embodiment.

[0187] 21 and 22 , the terahertz element 50 is disposed in the through-hole 127 of the main body 120. In other words, the through-hole 127 of the main body 120 accommodates the terahertz element 50. In this manner, the terahertz element 50 is disposed in the transmission region 38. More specifically, both the oscillation point P1 and the radiation point P2 of the terahertz element 50 are disposed in the transmission region 38. The terahertz element 50 is disposed with respect to the main body 120 so that the radiation direction of the electromagnetic wave is parallel to the central axis J of the main body 120.

[0188] 22, the first pad electrode 63c of the terahertz element 50 is electrically connected to the main conductor 27a of the support substrate 20 by a wire W1. The second pad electrode 64c is electrically connected to the ground conductor 27b of the support substrate 20 by a wire W2. The first pad electrode 63c may be connected to the ground conductor 27c, and the second pad electrode 64c may be connected to the main conductor 27a. There may be multiple wires W1 and W2. The number of wires W1 and W2 may be different.

[0189] The short-circuit portion 130 constitutes a part of the waveguide 100 and is attached to the rear surface 22 of the support substrate 20. The support substrate 20 is sandwiched between the main body 120 and the short-circuit portion 130. In other words, the support substrate 20 is disposed between the short-circuit portion 130 and the main body 120 in the z direction. The short-circuit portion 130 is formed of a conductive material that is non-transparent to the electromagnetic waves emitted or received by the terahertz element 50. This material may be Cu, a Cu alloy, Al, an Al alloy, or the like.

[0190] The short-circuit portion 130 is formed in the shape of a rectangular parallelepiped. The short-circuit portion 130 has a main surface 131 and a back surface 132 that face opposite each other in the z direction, and four outer surfaces 133 to 136 that are located between the main surface 131 and the back surface 132 in the z direction and intersect with the main surface 131 and the back surface 132.

[0191] 22 , outer surface 133 faces the same side as main body side surface 123 of main body portion 120, outer surface 134 faces the same side as main body side surface 124, outer surface 135 faces the same side as main body side surface 125, and outer surface 136 faces the same side as main body side surface 126. In this embodiment, outer surface 133 and main body side surface 123 are flush with each other, outer surface 134 and main body side surface 124 are flush with each other, outer surface 135 and main body side surface 125 are flush with each other, and outer surface 136 and main body side surface 126 are flush with each other.

[0192] The short circuit portion 130 is attached to the support substrate 20 by an adhesive layer (not shown). More specifically, the main surface 131 of the short circuit portion 130 faces the rear surface 22 of the support substrate 20 in the z direction. The adhesive layer is interposed between the main surface 131 of the short circuit portion 130 and the rear surface 22 of the support substrate 20 in the z direction.

[0193] The short-circuiting portion 130 closes one end of the transmission region 38 that penetrates the main body portion 120. This allows the waveguide 100 to have the transmission region 38 as a waveguide path that is open on one side and short-circuited on the other side.

[0194] The short-circuit portion 130 has a back-short portion 137. The back-short portion 137 is a recess that is recessed from the main surface 131 toward the back surface 132 of the short-circuit portion 130. The shape of the back-short portion 137 when viewed from the z direction is circular. The diameter of the back-short portion 137 is equal to the diameter of the through-hole 127 of the main body portion 120. The diameter of the back-short portion 137 is also equal to the minimum value of the diameter of the through-hole 37 of the antenna portion 110.

[0195] The lengths (thicknesses) in the z direction of the terahertz element 50, the support substrate 20, and the back-short portion 137 may be set, for example, in accordance with the frequency (wavelength) of the electromagnetic waves emitted by the terahertz element 50. Furthermore, the lengths (thicknesses) in the z direction of the terahertz element 50, the support substrate 20, and the back-short portion 137 may be set, for example, so as to align the phases of the respective elements.

[0196] 23 indicate the propagation (optical path) of electromagnetic waves in the terahertz device 10 of this embodiment. An active element 62 shown in FIGS. 6 and 7 is mounted on the element main surface 51 of the terahertz element 50, and the active element 62 oscillates terahertz waves as an oscillation point P1, and the antenna 65 radiates electromagnetic waves as a radiation point P2. In FIG. 23, the terahertz element 50 radiates electromagnetic waves in a direction perpendicular to the element main surface 51, that is, in a direction toward the opening of the main body 120 and a direction toward the short-circuit portion 130.

[0197] 23, an electromagnetic wave emitted from the element rear surface 52 side of the terahertz element 50 passes through the terahertz element 50, supporting substrate 20, and back-short portion 137 in this order, as indicated by the white arrow in Fig. 23, and is reflected by the bottom surface 137a of the back-short portion 137. The reflected electromagnetic wave passes through the back-short portion 137, supporting substrate 20, and terahertz element 50 in this order, and is radiated from the element main surface 51 of the terahertz element 50 into the inside of the main body 120 of the waveguide 100.

[0198] The terahertz element 50 is made of InP or the like, and the support substrate 20 is made of quartz glass or the like. The back-short portion 137 is a space, and electromagnetic waves propagate through the air.

[0199] In the terahertz element 50, the optical path length in the terahertz element 50 is set to an integer multiple of 2π. At the interface between the support substrate 20 and the back-short portion 137, the electromagnetic wave is reflected at the free end. In the back-short portion 137, the electromagnetic wave is fixedly reflected at the bottom surface 137a, resulting in a phase shift of π. Therefore, in the back-short portion 137, the phase is aligned by setting the optical path length to an odd multiple of π, taking into account the phase shift (π) due to reflection.

[0200] Based on the above, it is preferable that the thickness d1 of the terahertz element 50 is (λ1 / 2)×M (M is an integer equal to or greater than 1: M=1, 2, 3, ...). λ1 is the effective wavelength of the electromagnetic wave propagating inside the terahertz element 50. When the refractive index of the terahertz element 50 (element substrate 61) is n1, c is the speed of light, and fc is the center frequency of the electromagnetic wave, λ1 is given by (1 / n1)×(c / fc). At the interface between the terahertz element 50 and the support substrate 20, the electromagnetic wave is free-end reflected. By setting the thickness d1 of the terahertz element 50 in this manner, it is possible to align the phase.

[0201] The thickness d2 of the support substrate 20 is preferably set to (λ2 / 2)×M (M is an integer equal to or greater than 1: M=1, 2, 3, ...). λ2 is the effective wavelength of the electromagnetic wave propagating inside the support substrate 20. When the refractive index of the support substrate 20 is n2, c is the speed of light, and fc is the center frequency of the electromagnetic wave, λ2 is given by (1 / n2)×(c / fc). At the interface between the support substrate 20 and the space of the back-short portion 137, the electromagnetic wave is free-end reflected. In this way, the phase can be aligned by setting the thickness d2 of the support substrate 20.

[0202] The thickness d3 of the back-short portion 137 is preferably set to (λ / 4)+(λ / 2)×M (M is an integer equal to or greater than 0: M=0, 1, 2, ...). λ is the wavelength of the electromagnetic wave emitted by the terahertz element 50. In this way, by setting the thickness d1 of the terahertz element 50, the thickness d2 of the support substrate 20, and the thickness d3 of the back-short portion 137, the phase can be aligned.

[0203] (effect) According to the terahertz device 10 of this embodiment, the following effects can be obtained in addition to the effects of the first embodiment.

[0204] (4-1) The waveguide 100 includes a short-circuit portion 130 disposed on the side of the element rear surface 52 of the terahertz element 50. The short-circuit portion 130 has a back-short portion 137 recessed from the main surface 131 toward the rear surface 132. According to this configuration, the electromagnetic waves radiated from the element rear surface 52 of the terahertz element 50 are reflected by the bottom surface 137a of the back-short portion 137 and are radiated to the transmission region 38 of the waveguide 100. This increases the output of the electromagnetic waves radiated from the terahertz device 10. Therefore, the antenna gain of the terahertz device 10 can be improved.

[0205] (4-2) The thickness d1 of the terahertz element 50, the thickness d2 of the support substrate 20, and the thickness d3 of the back-short portion 137 are set in consideration of the phase due to the optical path length of the electromagnetic wave. With this configuration, the phase of the electromagnetic wave radiated toward the transmission region 38 can be aligned, and the terahertz element 50 can be efficiently coupled to the waveguide 100.

[0206] [Example of change] The above-described embodiments are examples of possible forms of the terahertz device according to the present disclosure and are not intended to limit the forms. The terahertz device according to the present disclosure may take forms different from those exemplified in the above-described embodiments. Examples of such forms include forms in which part of the configuration of the above-described embodiments is replaced, modified, or omitted, or forms in which new configurations are added to the above-described embodiments. Furthermore, the following modified examples can be combined with each other as long as there is no technical contradiction. In the following modified examples, parts common to the above-described embodiments are assigned the same reference numerals as the above-described embodiments, and their description will be omitted.

[0207] In the first embodiment, the shape of the reflecting surface 47a of the reflector 40 can be changed as desired. The reflecting surface 47a may be a flat inclined surface instead of a paraboloid of revolution or an aspherical curved concave surface. This inclined surface is inclined from the back surface 42 of the reflector 40 toward the main surface 41 and from the side surface 44 toward the side surface 43 of the reflector 40. The reflecting surface 47a may also be a spherical curved concave surface.

[0208] In the first embodiment, the size of the reflecting portion 47 can be changed as desired. The reflecting portion 47 only needs to cover at least the entire through-hole 37 of the waveguide 30. In other words, the tip 47b of the reflecting portion 47 may be provided at a position that does not intersect with the imaginary line LV (see FIG. 4) extending from the through-hole 37.

[0209] In the first embodiment, the shape of the through hole 37 of the waveguide 30 can be changed as desired. For example, as shown in Fig. 24, instead of being tapered, the through hole 37 may have a shape with a constant diameter in the z direction. Note that the waveguides 30 and 100 of the second and fourth embodiments may also be changed in the same way.

[0210] In the first embodiment, as shown in FIG. 25 , the waveguide 30 may be omitted from the terahertz device 10. In this case, the reflector 40 is mounted on the substrate main surface 21 of the support substrate 20. In one example, the reflector 40 is attached to the substrate main surface 21, for example, with an adhesive. Therefore, a second adhesive layer AH2 is formed between the rear surface 42 of the reflector 40 and the substrate main surface 21. The reflecting surface 47a of the reflector 40 is formed so as to cover the entire element main surface 51 of the terahertz element 50. In other words, the reflecting surface 47a is formed so as to be able to reflect all of the electromagnetic waves emitted from the terahertz element 50.

[0211] 25, device opening 17 is defined by reflector 40 and supporting substrate 20. More specifically, in terahertz device 10 of FIG. 25, tip 47b of reflecting surface 47a defines opening 40A of reflector 40, and device opening 17 can be said to be defined by tip 47b and substrate main surface 21 of supporting substrate 20. In other words, device opening 17 can be said to be the region between tip 47b and substrate main surface 21 of supporting substrate 20.

[0212] According to this configuration, it is possible to obtain the same effect as (1-1) of the first embodiment, and also to reduce the height of the terahertz device 10 by omitting the waveguide 30. Similarly, in the terahertz device 10 of the fourth embodiment, the waveguide 30 may be omitted from the terahertz device 10.

[0213] In the first embodiment, the reflector 40 is formed of a conductive material that is non-transparent to electromagnetic waves, but this is not limiting. In one example, as shown in FIG. 26 , the reflector 40 may be formed of a material that is transparent to electromagnetic waves. In this case, a conductive film 47e made of a conductive material that is non-transparent to electromagnetic waves is formed on a concave surface 47d that is a paraboloid of revolution, the same as the reflecting surface 47a of the first embodiment. In other words, the surface of the conductive film 47e forms a reflective surface that reflects electromagnetic waves. In the illustrated example, the conductive film 47e is formed from a base end 47f, which is the end of the concave surface 47d on the back surface 42 side of the reflector 40, to a tip end 47g, which is the end on the side surface 43 side of the reflector 40.

[0214] 26, conductive film 47e formed on tip portion 47g defines opening 40A of reflector 40, and device opening 17 can be said to be defined by conductive film 47e formed on tip portion 47g and main surface 31 of waveguide 30. In other words, device opening 17 can be said to be the region between conductive film 47e formed on tip portion 47g and main surface 31 of waveguide 30.

[0215] 26, the conductive film 47e formed on the base end 47f is disposed outward in a direction perpendicular to the z direction from the inner surface of the through hole 37 of the waveguide 30 that forms the opening corresponding to the main surface 31. In other words, the reflecting surface of the reflector 40 is located outward in a direction perpendicular to the z direction from the through hole 37 of the waveguide 30.

[0216] When the reflecting surface of reflector 40 is located inward of through-hole 37 of waveguide 30 in a direction perpendicular to the z direction, that is, when the reflecting surface of reflector 40 covers part of through-hole 37 from the back surface 42 of reflector 40, part of the electromagnetic waves radiated from terahertz element 50 is reflected by back surface 42 of reflector 40 and is not emitted to the outside of terahertz device 10. Note that the reflectors 40 and 90 of the second to fourth embodiments may also be modified in a similar manner.

[0217] In the modification of Fig. 25, as shown in Fig. 27, the reflector 40 may be modified to have the configuration shown in Fig. 26. That is, the reflector 40 is made of a material that is transparent to electromagnetic waves, and a conductive film 47e is formed on the concave surface 47d of the reflector 40. The reflector 40 of the fourth embodiment may also be modified in the same way.

[0218] 27, device opening 17 is defined by reflector 40 and supporting substrate 20. More specifically, in terahertz device 10 of FIG. 27, conductive film 47e formed on tip portion 47g defines opening 40A of reflector 40, and device opening 17 can be said to be defined by conductive film 47e formed on tip portion 47g and substrate main surface 21 of supporting substrate 20. In other words, device opening 17 can be said to be the region between conductive film 47e formed on tip portion 47g and substrate main surface 21 of supporting substrate 20.

[0219] In the first embodiment, the waveguide 30 is made of a conductive material that is non-transparent to electromagnetic waves, but this is not limiting. For example, as shown in FIG. 28 , the waveguide 30 may be made of a material that is transparent to electromagnetic waves. In this case, a conductive film 39 made of a conductive material that is non-transparent to electromagnetic waves is formed on the inner surface of the through-hole 37 of the waveguide 30. As a result, the electromagnetic waves radiated from the terahertz element 50 are reflected by the conductive film 39 and propagate toward the reflecting surface 47a of the reflector 40.

[0220] In the modification of Fig. 28, as shown in Fig. 29, the reflector 40 may be modified to have the configuration of the reflector 40 shown in Fig. 26. That is, the reflector 40 is made of a material that is transparent to electromagnetic waves, and a conductive film 47e is formed on the concave surface 47d of the reflector 40.

[0221] In the first embodiment, the waveguide 30 and the reflector 40 may be integrally formed. In this case, the waveguide 30 and the reflector 40 are an integrally formed single member. Similarly, the waveguide 100 and the reflector 40 in the fourth embodiment may also be integrally formed.

[0222] In the first embodiment, the shape of the through hole 37 of the waveguide 30 can be changed as desired. In one example, as shown in Fig. 30, the through hole 37 has a first inner surface portion 37b whose diameter is constant in the z direction, and a second inner surface portion 37c whose diameter tapers and increases from the first inner surface portion 37b toward the pipe main surface 31. That is, the transmission region 38 has a first transmission region 38A whose area is constant in the z direction as viewed from the z direction, and a second transmission region 38B whose area as viewed from the z direction increases from the first transmission region 38A toward the pipe main surface 31.

[0223] The first inner surface portion 37b is adjacent to the support substrate 20 in the z direction. Therefore, the terahertz element 50 is housed in the first inner surface portion 37b. In other words, the terahertz element 50 is disposed in the first transmission region 38A. In the illustrated example, the element main surface 51 of the terahertz element 50 is located closer to the substrate main surface 21 of the support substrate 20 than the second inner surface portion 37c.

[0224] In the second embodiment, the waveguide 30 and the reflector 40 may be fixed to each other with an adhesive. Alternatively, the waveguide 30 and the reflector 40 may be joined to each other by heat treatment or the like. In other words, the reflector 40 may be fixed to the waveguide 30 so as not to be detachable.

[0225] In the second embodiment, the first mounting portion 49A and the second mounting portion 49B of the reflector 40 may be formed separately. That is, the mounting portion for mounting the reflector 40 and the waveguide 30 of the first embodiment may be provided as a separate component from the reflector 40 and the waveguide 30. In this case, the mounting portion 49 may be omitted from the reflector 40. Furthermore, the waveguide 30 may have a mounting portion for mounting the reflector 40. In this case, the mounting portion 49 may be omitted from the reflector 40.

[0226] In the second embodiment, the second attachment portion 49B may be omitted from the attachment portion 49 of the reflector 40. In this case, the base end portion 47c of the reflecting surface 47a is connected to the rear surface 42 of the reflector 40. Therefore, when the reflector 40 is attached to the waveguide 30, the reflecting surface 47a is connected to the main surface 31 of the waveguide 30 via the second adhesive layer AH2.

[0227] In the second embodiment, the waveguide 100 may be used instead of the waveguide 30. That is, the terahertz device 10 of the second embodiment may include a short-circuit portion 130. In other words, the reflector 40 of the terahertz device 10 of the fourth embodiment may be changed to the reflector 40 of the second embodiment.

[0228] In the third embodiment, a waveguide may be disposed between the support substrate 80 and the reflector 90 in the z direction. The waveguide is made of a conductive material that is non-transparent to electromagnetic waves and is formed in the shape of a rectangular frame having a through-hole that penetrates the waveguide in the z direction. The space formed by the through-hole becomes a transmission region that transmits electromagnetic waves from the terahertz element 50. A plurality of terahertz elements 50 are disposed within the transmission region. In other words, the waveguide accommodates a plurality of terahertz elements 50. The waveguide is attached to the substrate main surface 81 of the support substrate 80, for example, by an adhesive. The reflector 90 is attached to the waveguide, for example, by an adhesive. In this case, the attachment portion 90B may be omitted from the reflector 90.

[0229] The attachment structure of the reflector 90 to the waveguide is not limited to adhesive, and may be a detachable attachment structure. For example, the reflector 90 may have an attachment portion that is detachable from the waveguide, like the reflector 40 of the second embodiment.

[0230] In the third embodiment, the vertical surface 99 may be omitted from the reflector 90. In this case, the reflecting surface 98 is connected to the rear surface 92 of the reflector 90. Therefore, when the reflector 90 is attached to the support substrate 80, the reflecting surface 98 is connected to the substrate main surface 81 of the support substrate 80.

[0231] In the third embodiment, instead of the pin header, multiple exterior terminals may be provided on the rear surface 82 of the support substrate 80. The exterior terminals are made of, for example, a conductive layer formed on the rear surface 82 of the substrate. The conductive layer is made of, for example, copper foil. The multiple exterior terminals are connected to the main conductor 88A and the ground conductor 88C, respectively, by plated through holes or filled vias. This allows the terahertz device 10 of this modified example to be surface-mounted when the terahertz device 10 is mounted on, for example, a circuit board.

[0232] In the third embodiment, the main conductor 88A and the ground conductor 88C each extend closer to the substrate side surface 83 than the reflector 90. In other words, the main conductor 88A and the ground conductor 88C each extend to the outside of the reflector 90. However, this is not limited to this. The conductor portions 88p, 88q of the main conductor 88A and the ground conductor 88C may be formed closer to the substrate side surface 84 than the side surface 93 of the reflector 90 when viewed from the z direction. With this configuration, the lengths of the main conductor 88A and the ground conductor 88C are shortened, thereby shortening the length of the conductive path from each terahertz element 50 to the exterior terminal. This reduces the inductance caused by the length of each conductive path.

[0233] In the third embodiment, a partition wall may be provided on the reflector 90 side. In one example, the reflector 90 is provided with a partition wall (not shown) that separates adjacent terahertz elements 50 in the x direction. The partition wall is provided so as to hang down from the reflecting surface 98 of the reflector 90. The tip surface of the partition wall in the z direction is in contact with the substrate main surface 81 of the support substrate 80. An adhesive layer may be formed between the tip surface of the partition wall and the substrate main surface 81. The arrangement position of the partition wall can be changed as desired. In one example, the partition wall may be provided so as to separate each of a plurality of terahertz elements 50 in the x direction.

[0234] In the fourth embodiment, the main body 120 may be omitted from the waveguide 30. In this case, the connector 140 may be a connector that can be mounted on the support substrate 80, instead of an SMP connector.

[0235] In the fourth embodiment, the terahertz element 50 is mounted on the substrate main surface 21 of the support substrate 20, but this is not limiting. The terahertz element 50 may be mounted on the substrate rear surface 22 of the support substrate 20. In this case, the terahertz element 50 radiates an electromagnetic wave toward the short-circuit portion 130. The electromagnetic wave is reflected at the short-circuit portion 130, propagates through the support substrate 20, the main body portion 120, and the antenna portion 110, and is reflected by the reflecting surface 47a of the reflector 40. The reflected electromagnetic wave propagates in the y direction and is emitted to the outside of the terahertz device 10.

[0236] In the first, second, and fourth embodiments, the outer shape of the waveguide 30, 100 can be changed as desired. For example, the outer shape of the waveguide 30, 100 viewed from the z direction may not be square, but may be rectangular with one of the x and y directions as the long side and the other of the x and y directions as the short side. Furthermore, the outer shape of the waveguide 30, 100 viewed from the z direction may not be rectangular, but may be circular, elliptical, oval (track-shaped), or polygonal. The shape of the mounting portion 49 in the second embodiment can be changed according to the outer shape of the waveguide 30.

[0237] The waveguides 30, 100 in the first, second and fourth embodiments are circular waveguides in which the transmission region 38 is circular, but they may also be rectangular waveguides in which the shape of the transmission region (through holes 37, 127) when viewed from the z direction is rectangular.

[0238] In each embodiment, the connection configuration between the terahertz element 50 and the power supply line 27 (power supply line 88) is not limited to wires W1 and W2 and can be changed as desired. In one example, as shown in FIG. 31 , the terahertz element 50 may be flip-chip mounted to the power supply line 27. More specifically, a bump 57 is provided on the element rear surface 52 of the terahertz element 50. In the example shown, the bump 57 protrudes from the element rear surface 52 toward the substrate main surface 21 of the support substrate 20. In the z direction, the power supply line 27 is provided to face the bump 57 in the z direction.

[0239] This configuration allows the length of the conductive path between the terahertz element 50 and the feed line 27 (feed line 88) to be shorter than that of the wires W1 and W2, thereby enabling faster signal transmission. Also, the influence of the wire connecting the terahertz element 50 and the support substrate 20 on the propagation mode in the waveguides 30 and 100 can be reduced.

[0240] In each embodiment, at least a portion of the terahertz element 50 may be embedded in the support substrate 20, 80. With this configuration, the wires W1, W2 connecting the terahertz element 50 and the support substrate 20, 80 become shorter, enabling faster signal transmission. From the viewpoint of shortening the wires W1, W2, it is preferable that the element main surface 51 of the terahertz element 50 and the substrate main surfaces 21, 81 of the support substrate 20, 80 are flush with each other.

[0241] In the first, second, and fourth embodiments, a reflective film that reflects electromagnetic waves may be formed on the substrate main surfaces 21, 81 of the support substrates 20, 80. The reflective film is made of, for example, Cu. The reflective film is connected to, for example, the ground conductor 27b and is formed continuously. In this case, the electromagnetic waves are reflected by the reflective film at fixed ends, resulting in a phase shift of π. For this reason, when the wavelength of the electromagnetic waves in the terahertz element 50 is λ1, the size of the terahertz element 50 in the z direction should be (λ1 / 4) + (an integer multiple of (λ1 / 2)).

[0242] The reflective film may be formed on, for example, the terahertz element 50. For example, in the element substrate 61, a reflective film is formed on the element back surface 52 opposite to the element main surface 51 on which the active element 62 is arranged. The reflective film is made of, for example, Au / Ti, Au / Pd / Ti, or the like. Furthermore, a reflective film may be formed on both the substrate main surface 21 of the support substrate 20 and the element back surface 52 of the terahertz element 50.

[0243] In each embodiment, the terahertz element 50 may convert incident terahertz-band electromagnetic waves into electrical energy. In other words, the terahertz element 50 receives terahertz-band electromagnetic waves and converts the electromagnetic waves into electrical energy. In this way, the terahertz element 50 detects terahertz waves. A terahertz device 10 including a terahertz element 50 that receives and detects terahertz-band electromagnetic waves will be specifically described using the terahertz device 10 of the first embodiment.

[0244] The active element 62 of the terahertz element 50 converts incident electromagnetic waves in the terahertz band (terahertz waves) into electrical energy. As a result, the terahertz element 50 receives the terahertz waves at the antenna 65 and detects them at the active element 62. Therefore, the antenna 65 can be said to be a receiving point that receives the terahertz waves, and can also be said to be a resonance point that resonates with the terahertz waves. Therefore, the terahertz element 50 has a receiving point and a detection point at the center of the element principal surface 51. In this case, the power supply line 27 formed on the support substrate 20 functions as a transmission line that outputs the electrical energy converted by the terahertz element 50 as an electrical signal to the outside of the terahertz device 10.

[0245] Furthermore, the terahertz element 50 may be one that both oscillates and detects terahertz waves, and the active element 62 can be said to be an oscillation point and a detection point. In this case, the power supply line 27 formed on the support substrate 20 functions both as a line that supplies a high-frequency electrical signal for the terahertz element 50 to emit an electromagnetic wave, and as a transmission line that outputs the electrical energy converted by the terahertz element 50 as an electronic signal to the outside of the terahertz device 10.

[0246] In the first and second embodiments, when electromagnetic waves in the terahertz band propagating in a direction intersecting the thickness direction (z direction) of the terahertz element 50 are incident from outside the terahertz device 10 toward the device opening 17 of the terahertz device 10, the electromagnetic waves that have propagated through the device opening 17 are reflected by the reflecting surface 47a of the reflector 40. The electromagnetic waves reflected by the reflecting surface 47a propagate within the transmission region 38 toward the support substrate 20, i.e., toward the terahertz element 50. The terahertz element 50 receives the electromagnetic waves reflected by the reflecting surface 47a. Here, when the terahertz element 50 receives electromagnetic waves, the device opening 17 can be said to be an incident portion through which the electromagnetic waves are input to the terahertz element 50 from outside.

[0247] According to this configuration, the electromagnetic waves propagating through the device opening 17 in a direction intersecting the thickness direction of the terahertz element 50 (y direction) are reflected by the reflecting surface 47a of the reflector 40 and propagate toward the terahertz element 50. This makes it possible to improve the antenna gain for the electromagnetic waves propagating in a direction intersecting the thickness direction of the terahertz element 50.

[0248] 11 , when terahertz element 50 receives and detects electromagnetic waves, it receives and detects electromagnetic waves that pass through support substrate 210 from outside terahertz device 10 and are reflected by reflecting surface 205 of spherical recess 204. Therefore, when electromagnetic waves are incident on terahertz device 10X from outside, the incident electromagnetic waves are reflected by reflecting surface 205 toward element main surface 51 of terahertz element 50, allowing terahertz element 50 to suitably receive the electromagnetic waves.

[0249] Incidentally, in the terahertz device 10X of the comparative example, a part of the electromagnetic waves incident from the outside of the terahertz device 10X toward the reflecting surface 205 may hit the power feed line 213 and not be incident on the reflecting surface 205. In this way, since the power feed line 213 is arranged on the path along which the electromagnetic waves are incident from the outside to the inside of the terahertz device 10X, the electromagnetic waves are blocked by the power feed line 213.

[0250] To address this problem, in the terahertz device 10, as shown in FIG. 4 , the terahertz element 50 is mounted on the substrate main surface 21 of the support substrate 20 on which the power feed line 27 is formed. Therefore, the element main surface 51 of the terahertz element 50 is disposed closer to the reflector 40 in the z direction than the power feed line 27. In other words, the power feed line 27 is disposed on the opposite side of the element main surface 51 of the terahertz element 50 in the incident direction of the electromagnetic wave. In other words, the power feed line 27 is not disposed on the path along which the electromagnetic wave propagates from the outside to the inside of the terahertz device 10. Therefore, it is possible to avoid the electromagnetic wave being blocked by the power feed line 27.

[0251] Moreover, in the third embodiment, electromagnetic waves incident on the terahertz device 10 from outside the terahertz device 10 are reflected by the reflecting surface 98 toward the substrate main surface 81 via the opening 97. Each terahertz element 50 mounted on the substrate main surface 81 receives the electromagnetic waves reflected by the reflecting surface 98. At this time, the electromagnetic waves are reflected by the reflecting surface 98, thereby increasing the directivity of the electromagnetic waves, thereby improving the antenna gain.

[0252] In each embodiment, the oscillation point P1 and the radiation point P2 of the terahertz element 50 may be located at different positions. For example, the oscillation point P1 may be located between the antenna 65 (radiation point P2) and the first pad electrode 63c and the second pad electrode 64c. Similarly, the reception point and the detection point of the terahertz element 50 may be located at different positions. For example, the detection point may be located between the antenna 65 (reception point) and the first pad electrode 63c and the second pad electrode 64c.

[0253] [Note] The technical ideas that can be understood from the above-described embodiments and modifications will be described below. (Appendix A1) a terahertz element having a main surface and a back surface facing the opposite side to the main surface, emitting electromagnetic waves in the terahertz band, and having a thickness direction perpendicular to the main surface; a reflector that is disposed at a position facing the element main surface at an interval in the thickness direction and has a reflective surface that reflects the electromagnetic waves emitted by the terahertz element in the thickness direction in a direction intersecting the thickness direction. Terahertz device.

[0254] (Appendix A2) The terahertz element has an active element at the oscillation point that converts the electromagnetic wave into the electrical energy. 1. A terahertz device as described in Appendix A1.

[0255] (Appendix A3) The terahertz element is connected to the active element and includes an antenna that radiates the electromagnetic waves in a direction perpendicular to the main surface of the element and toward the reflecting surface. A terahertz device as described in Appendix A2.

[0256] (Appendix A4) The active element is any one of a resonant tunneling diode, a Tannet diode, an in-pad diode, a GaAs-based field effect transistor, a GaN-based FET, a high electron mobility transistor, and a heterojunction bipolar transistor. A terahertz device as described in Appendix A2.

[0257] (Appendix A5) The antenna is one of a dipole antenna, a bowtie antenna, a slot antenna, a patch antenna, and a ring antenna. Terahertz device as described in Appendix A3.

[0258] (Appendix A6) a support substrate having a substrate main surface; the terahertz element is mounted on the substrate main surface so that the element main surface faces the same side as the substrate main surface; A transmission line connected to the terahertz element is provided on the main surface of the substrate. A terahertz device according to any one of appendices A1 to A5.

[0259] (Appendix A7) The terahertz element is connected to the transmission line by a wire. A terahertz device as described in Appendix A6.

[0260] (Appendix A8) The terahertz element is connected to the transmission line by a bump. A terahertz device as described in Appendix A6.

[0261] (Appendix A9) The transmission line is any one of a coplanar line, a microstrip line, a strip line, and a slot line. A terahertz device according to any one of appendices A6 to A8.

[0262] (Appendix A10) a support substrate on which the terahertz element is mounted; a waveguide mounted on the support substrate and having a transmission region for transmitting the electromagnetic wave; The terahertz element is The element has an oscillation point for oscillating the electromagnetic wave and a radiation point for radiating the electromagnetic wave on the main surface thereof, and The radiation point is positioned at the center of the transmission area. A terahertz device according to any one of appendices A1 to A9.

[0263] (Appendix A11) a support substrate having a substrate main surface; a waveguide mounted on the main surface of the substrate and having a transmission region for transmitting the electromagnetic wave; the terahertz element is mounted on the substrate main surface so that the element main surface faces the same side as the substrate main surface within the transmission region; the reflector is provided on the waveguide on a side opposite to a side on which the support substrate is disposed with respect to the waveguide, The waveguide is made of a conductive material that is non-transparent to the electromagnetic waves. A terahertz device according to any one of appendices A1 to A11.

[0264] (Appendix A12) a support substrate having a substrate main surface; a waveguide mounted on the main surface of the substrate and having a transmission region for transmitting the electromagnetic wave; the reflector is provided on the waveguide on a side opposite to a side on which the support substrate is disposed with respect to the waveguide, the waveguide has a through hole that penetrates the waveguide in the thickness direction and forms the transmission region, and is made of a material that is transparent to the electromagnetic wave; the terahertz element is mounted on the substrate main surface so that the element main surface faces the same side as the substrate main surface within the through hole in the transmission region, A conductive film made of a conductive material that is non-transparent to the electromagnetic waves is formed on the inner surface that constitutes the through hole. A terahertz device according to any one of appendices A1 to A11.

[0265] (Appendix A13) The terahertz element has a reflecting portion on the rear side thereof that reflects the electromagnetic wave. A terahertz device according to any one of appendices A1 to A12.

[0266] (Appendix A14) a support substrate having a substrate main surface; a waveguide mounted on the support substrate and having a transmission region for transmitting the electromagnetic wave; the terahertz element is mounted on the substrate main surface so that the element main surface faces the same side as the substrate main surface within the transmission region; the waveguide includes a main body portion that forms the transmission region and a short-circuit portion that short-circuits one end side of the transmission region, The reflecting portion is the bottom surface of a recess formed in the short-circuit portion. 1. A terahertz device as described in Appendix A13.

[0267] (Appendix A15) a support substrate having a substrate main surface; a waveguide mounted on the main surface of the substrate and having a transmission region for transmitting the electromagnetic wave, the terahertz element is mounted on the substrate main surface so that the element main surface faces the same side as the substrate main surface within the transmission region; the reflector is detachably attached to the waveguide on a side opposite to a side on which the support substrate is disposed with respect to the waveguide, The reflector has a step portion that abuts against the waveguide in the thickness direction. A terahertz device according to any one of appendices A1 to A10.

[0268] (Appendix A16) a support substrate on which the terahertz element is mounted; a waveguide mounted on the support substrate and having a transmission region for transmitting the electromagnetic wave; the reflector is provided on the waveguide on a side opposite to a side on which the support substrate is disposed with respect to the waveguide, the waveguide has a through hole that penetrates the waveguide in the thickness direction and forms the transmission region, the terahertz element is mounted on the substrate main surface so that the element main surface faces the same side as the substrate main surface within the through hole in the transmission region, A base end portion of the reflecting surface, which is an end portion closer to the waveguide, is disposed at the same position as the inner surface constituting the through hole or further outward than the inner surface when viewed from the thickness direction. A terahertz device according to any one of appendices A1 to A10.

[0269] (Appendix B1) 1. A terahertz device, comprising: a terahertz element having a main surface and a back surface facing the opposite side to the main surface, which receives and detects electromagnetic waves in the terahertz band and has a thickness direction perpendicular to the main surface; a reflector having an opening that opens in a direction intersecting the thickness direction and a reflecting surface that is arranged at a position facing the element main surface with an interval in the thickness direction, The reflecting surface reflects electromagnetic waves propagating from the outside of the terahertz device through the opening in a direction toward the terahertz element. Terahertz device.

[0270] (Appendix B2) The terahertz element has a receiving point for receiving the electromagnetic wave and a detecting point for detecting the electromagnetic wave on the element main surface. 1. A terahertz device as described in Appendix B1.

[0271] (Appendix B3) The terahertz element has an active element at the detection point that converts the electromagnetic wave into electrical energy. 1. A terahertz device as described in Appendix B2.

[0272] (Appendix B4) The terahertz element is connected to the active element and includes an antenna whose thickness direction is the direction in which the electromagnetic waves are received. 1. A terahertz device as described in Appendix B3.

[0273] (Appendix B5) The active element is any one of a resonant tunneling diode, a Tannet diode, an IMPATT diode, a GaAs-based field effect transistor, a GaN-based FET, a high electron mobility transistor, and a heterojunction bipolar transistor. 1. A terahertz device according to any one of claims B3 to B4.

[0274] (Appendix B6) The antenna is one of a dipole antenna, a bowtie antenna, a slot antenna, a patch antenna, and a ring antenna. A terahertz device as described in Appendix B4.

[0275] (Appendix B7) The thickness direction is defined as the z direction, and the direction perpendicular to the z direction and in which the electromagnetic wave is reflected is defined as the y direction, the reflecting surface has a curved shape extending in the y direction as it becomes farther away from the terahertz element in the z direction, and has, as both end portions in the z direction, a base end and a tip end that is farther away from the terahertz element than the base end, When the distance between the base end portion and the radiation point of the terahertz element that radiates the electromagnetic wave in a direction perpendicular to the z direction is defined as f, the curved shape of the reflecting surface is expressed as follows: The yz coordinate of the yz plane defined by the z direction and the y direction is y=z 2 Set by / 4f A terahertz device according to any one of Appendixes B1 to B6.

[0276] (Appendix B8) The reflecting surface is a paraboloid of revolution. A terahertz device according to any one of Appendixes B1 to B7.

[0277] (Appendix B9) a support substrate having a substrate main surface; a waveguide mounted on the main surface of the substrate and having a transmission region for transmitting the electromagnetic wave, the terahertz element is mounted on the substrate main surface so that the element main surface faces the same side as the substrate main surface within the transmission region; The reflector is provided on the waveguide on a side opposite to a side on which the support substrate is disposed. A terahertz device according to any one of Appendixes B1 to B8.

[0278] (Appendix B10) the reflector and the waveguide are formed separately, The reflector is attached to the waveguide. 1. A terahertz device as described in Appendix B9.

[0279] (Appendix B11) The reflector is detachably attached to the waveguide. 1. The terahertz device according to claim B10.

[0280] (Appendix B12) the waveguide has a through hole that penetrates the waveguide in the thickness direction and forms the transmission region, the terahertz element is disposed in the through hole, The reflecting surface is provided so as to cover the entire through hole when viewed from the thickness direction. The terahertz device according to any one of Appendix B9 to B11.

[0281] (Appendix B13) inner surfaces constituting the through hole have tapered surfaces that move away from each other as they move from the support substrate toward the reflector, When viewed from the thickness direction, the reflecting surface covers the entire area extending from the tapered surface along the tapered surface in the thickness direction. 1. A terahertz device as described in Appendix B12.

[0282] (Appendix B14) The waveguide is made of a conductive material that is non-transparent to the electromagnetic waves. A terahertz device according to any one of Appendixes B9 to B13.

[0283] (Appendix B15) the waveguide has a through hole that penetrates the waveguide in the thickness direction and forms the transmission region, and is made of a material that is transparent to the electromagnetic wave; the terahertz element is mounted on the substrate main surface in the through hole so that the element main surface faces the same side as the substrate main surface, A conductive film made of a conductive material that is non-transparent to the electromagnetic waves is formed on the inner surface that constitutes the through hole. A terahertz device according to any one of Appendixes B9 to B13.

[0284] (Appendix B16) The terahertz element is a receiving point for receiving the electromagnetic wave and a detecting point for detecting the electromagnetic wave on the element main surface; The detection point is arranged to be located at the center of the transmission area. A terahertz device according to any one of Appendixes B9 to B15.

[0285] (Appendix B17) a support substrate having a substrate main surface; the terahertz element is mounted on the substrate main surface so that the element main surface faces the same side as the substrate main surface; The reflector is mounted on the main surface of the substrate. A terahertz device according to any one of Appendixes B1 to B8.

[0286] (Appendix B18) a support substrate having a substrate main surface; the terahertz element is mounted on the substrate main surface so that the element main surface faces the same side as the substrate main surface; A transmission line connected to the terahertz element is provided on the main surface of the substrate. A terahertz device according to any one of Appendixes B1 to B8.

[0287] (Appendix B19) The terahertz element is connected to the transmission line by a wire. 10. The terahertz device according to claim B18.

[0288] (Appendix B20) The terahertz element is connected to the transmission line by a bump. 10. The terahertz device according to claim B18.

[0289] (Appendix B21) The transmission line is any one of a coplanar line, a microstrip line, a strip line, and a slot line. A terahertz device according to any one of Appendices B18 to B20.

[0290] (Appendix B22) The terahertz element has a reflecting portion on the rear side thereof that reflects the electromagnetic wave. A terahertz device according to any one of appendices B1 to B8.

[0291] (Appendix B23) a support substrate having a substrate main surface; a waveguide mounted on the support substrate and having a transmission region for transmitting the electromagnetic wave; the terahertz element is mounted on the substrate main surface so that the element main surface faces the same side as the substrate main surface within the transmission region; the waveguide includes a main body portion that forms the transmission region and a short-circuit portion that short-circuits one end side of the transmission region, The reflecting portion is the bottom surface of a recess formed in the short-circuit portion. 10. The terahertz device according to claim B22.

[0292] (Appendix B24) The reflector has a step portion that abuts against the waveguide in the thickness direction. 1. A terahertz device as described in Appendix B11.

[0293] (Appendix B25) A base end portion of the reflecting surface, which is an end portion closer to the waveguide, is disposed at the same position as the inner surface constituting the through hole or further outward than the inner surface when viewed from the thickness direction. 1. A terahertz device as described in Appendix B12.

[0294] (Appendix B26) the support substrate has a substrate main surface facing a side where the reflector is disposed and a substrate back surface facing a side opposite to the substrate main surface, the terahertz element is mounted on the substrate main surface so that the element main surface faces the same side as the substrate main surface; An exterior terminal electrically connected to the terahertz element is provided on the rear surface of the substrate. A terahertz device according to any one of Appendices B9 to B21 and B23 to B25.

[0295] (Appendix B27) a plurality of the terahertz elements are provided, The reflector is provided so as to cover the element principal surfaces of the plurality of terahertz elements in the thickness direction. 1. A terahertz device as described in Appendix B1.

[0296] (Appendix B28) a support substrate having a substrate main surface; each of the plurality of terahertz elements is mounted on the substrate main surface so that the element main surface faces the same side as the substrate main surface, and has a main electrode and a ground electrode; a power supply line electrically connected to each of the terahertz elements is provided on a main surface of the substrate; The power supply line includes a plurality of main conductors electrically connected to the main electrodes of the plurality of terahertz elements individually, and a ground conductor electrically connected in common to the ground electrodes of the plurality of terahertz elements. 1. A terahertz device as described in Appendix B27.

[0297] (Appendix B29) The reflector is made of a conductive material that is non-transparent to the electromagnetic waves. A terahertz device according to any one of Appendices B1 to B28.

[0298] (Appendix B30) the reflector is made of a material that is transparent to the electromagnetic wave, The reflecting surface is formed with a conductive film made of a conductive material that is non-transparent to the electromagnetic waves. A terahertz device according to any one of Appendices B1 to B28.

[0299] (Appendix C1) a terahertz element having a main surface and a back surface facing the opposite side to the main surface, emitting electromagnetic waves in the terahertz band, and having a thickness direction perpendicular to the main surface; a reflector that is disposed at a position facing the element main surface at an interval in the thickness direction and has a reflecting surface that reflects the electromagnetic waves emitted by the terahertz element in the thickness direction in a direction intersecting the thickness direction. Terahertz device.

[0300] (Appendix C2) The terahertz element has an oscillation point for oscillating the electromagnetic wave and an emission point for radiating the electromagnetic wave on the main surface of the element. 1. The terahertz device according to claim C1.

[0301] (Appendix C3) The thickness direction is defined as the z direction, and the direction perpendicular to the z direction and in which the electromagnetic wave is reflected is defined as the y direction, the reflecting surface has a curved shape extending in the y direction as it becomes farther away from the terahertz element in the z direction, and has, as both end portions in the z direction, a base end and a tip end that is farther away from the terahertz element than the base end, When the distance between the base end portion and the radiation point of the terahertz element that radiates the electromagnetic wave in a direction perpendicular to the z direction is defined as f, the curved shape of the reflecting surface is expressed as follows: The yz coordinate of the yz plane defined by the z direction and the y direction is y=z 2 Set by / 4f 10. The terahertz device according to claim 9, wherein the terahertz wavelength is 100 nm or less.

[0302] (Appendix C4) The reflecting surface is a paraboloid of revolution. A terahertz device according to any one of Appendix C1 to Appendix C3.

[0303] (Appendix C5) a support substrate having a substrate main surface; a power supply line formed on the main surface of the substrate and electrically connected to the terahertz element; The terahertz element is mounted on the main surface of the substrate so that the main surface of the element faces the same side as the main surface of the substrate. A terahertz device according to any one of Appendix C1 to Appendix C4.

[0304] (Appendix C6) a support substrate having a substrate main surface; a waveguide mounted on the main surface of the substrate and having a transmission region for transmitting the electromagnetic wave; the terahertz element is mounted on the substrate main surface so that the element main surface faces the same side as the substrate main surface within the transmission region; The reflector is provided on the waveguide on a side opposite to a side on which the support substrate is disposed. A terahertz device according to any one of Appendix C1 to Appendix C4.

[0305] (Appendix C7) the reflector and the waveguide are formed separately, The reflector is attached to the waveguide. 1. A terahertz device as described in Appendix C6.

[0306] (Appendix C8) The reflector is detachably attached to the waveguide. 1. A terahertz device as described in Appendix C7.

[0307] (Appendix C9) the waveguide has a through hole that penetrates the waveguide in the thickness direction and forms the transmission region, the terahertz element is disposed in the through hole, The reflecting surface is provided so as to cover the entire through hole when viewed from the thickness direction. The terahertz device according to any one of Appendix C6 to Appendix C8.

[0308] (Appendix C10) inner surfaces constituting the through hole have tapered surfaces that move away from each other as they move from the support substrate toward the reflector, When viewed from the thickness direction, the reflecting surface covers the entire area extending from the tapered surface along the tapered surface in the thickness direction. 1. A terahertz device as described in Appendix C9.

[0309] (Appendix C11) a support substrate having a substrate main surface; the terahertz element is mounted on the substrate main surface so that the element main surface faces the same side as the substrate main surface; The reflector is mounted on the main surface of the substrate. A terahertz device according to any one of Appendix C1 to Appendix C4.

[0310] (Appendix C12) a support substrate having a substrate main surface and a substrate back surface facing opposite to each other in the thickness direction; the terahertz element is mounted on the main surface of the substrate, An exterior terminal electrically connected to the terahertz element is provided on the rear surface of the substrate. A terahertz device according to any one of Appendix C1 to Appendix C4.

[0311] (Appendix C13) a plurality of the terahertz elements are provided, The reflector is provided so as to cover the element principal surfaces of the plurality of terahertz elements in the thickness direction. A terahertz device according to any one of Appendix C1 to Appendix C4.

[0312] (Appendix C14) a support substrate having a substrate main surface; each of the plurality of terahertz elements is mounted on the substrate main surface so that the element main surface faces the same side as the substrate main surface, and has a main electrode and a ground electrode; a power supply line electrically connected to each of the terahertz elements is provided on a main surface of the substrate; The power supply line includes a plurality of main conductors electrically connected to the main electrodes of the plurality of terahertz elements individually, and a ground conductor electrically connected in common to the ground electrodes of the plurality of terahertz elements. 1. A terahertz device as described in Appendix C13.

[0313] (Appendix C15) The reflector is made of a conductive material that is non-transparent to the electromagnetic waves. A terahertz device according to any one of Appendix C1 to Appendix C14.

[0314] (Appendix C16) the reflector is made of a material that is transparent to the electromagnetic wave, The reflecting surface is formed with a conductive film made of a conductive material that is non-transparent to the electromagnetic waves. A terahertz device according to any one of Appendix C1 to Appendix C14.

[0315] (Appendix C17) a terahertz element having a main surface and a back surface facing the opposite side to the main surface, which receives and detects electromagnetic waves in the terahertz band and has a thickness direction perpendicular to the main surface; a reflector having an opening that opens in a direction intersecting the thickness direction and a reflecting surface that is arranged at a position facing the element main surface with an interval in the thickness direction, The reflecting surface reflects electromagnetic waves propagating from the outside of the terahertz device through the opening in a direction toward the terahertz element. Terahertz device.

[0316] (Appendix D1) a terahertz element having a main surface and a back surface facing the opposite side to the main surface, emitting electromagnetic waves in the terahertz band, and having a thickness direction perpendicular to the main surface; a reflector that is disposed at a position facing the element main surface at an interval in the thickness direction and has a reflective surface that reflects electromagnetic waves emitted by the terahertz element in the thickness direction in a direction intersecting the thickness direction; A terahertz device comprising:

[0317] With this configuration, the electromagnetic waves radiated from the terahertz element are reflected by the reflecting surface of the reflector, and are emitted to the outside of the terahertz device with enhanced directivity in a direction intersecting the thickness direction of the terahertz element, thereby improving the antenna gain.

[0318] (Appendix D2) a terahertz element having a main surface and a back surface facing the opposite side to the main surface, which receives and detects electromagnetic waves in the terahertz band and has a thickness direction perpendicular to the main surface; a reflector having an opening that opens in a direction intersecting the thickness direction and a reflecting surface that is arranged at a position facing the element main surface with an interval in the thickness direction, The reflective surface reflects electromagnetic waves propagating from the outside of the terahertz device through the opening in a direction toward the terahertz element.

[0319] With this configuration, electromagnetic waves propagating through the opening in a direction intersecting the thickness direction of the terahertz element are reflected by the reflecting surface of the reflector and propagate toward the terahertz element, thereby improving the antenna gain for electromagnetic waves propagating in a direction intersecting the thickness direction of the terahertz element.

[0320] (Appendix E1) a terahertz element having a main surface and a back surface facing the opposite side to the main surface, the main surface having an oscillation point for oscillating electromagnetic waves in the terahertz band and an emission point for radiating the electromagnetic waves, and the thickness direction of the terahertz element being perpendicular to the main surface; a reflector that is disposed at a position facing the element main surface at an interval in the thickness direction and has a reflecting surface that reflects the electromagnetic waves emitted by the terahertz element in the thickness direction in a direction intersecting the thickness direction. Terahertz device.

[0321] (Appendix E2) The thickness direction is defined as the z direction, and the direction perpendicular to the z direction and in which the electromagnetic wave is reflected is defined as the y direction, the reflecting surface has a curved shape extending in the y direction as it becomes farther away from the terahertz element in the z direction, and has, as both end portions in the z direction, a base end and a tip end that is farther away from the terahertz element than the base end, When the distance between the base end portion and the radiation point of the terahertz element that radiates the electromagnetic wave in a direction perpendicular to the z direction is defined as f, the curved shape of the reflecting surface is expressed as follows: The yz coordinate of the yz plane defined by the z direction and the y direction is y=z 2 / 4f Set by 1. The terahertz device of claim 1.

[0322] (Appendix E3) The reflecting surface is a paraboloid of revolution. 10. The terahertz device of claim 1 or E2.

[0323] (Appendix E4) a support substrate having a substrate main surface; a power supply line formed on the main surface of the substrate and electrically connected to the terahertz element; The terahertz element is mounted on the main surface of the substrate so that the main surface of the element faces the same side as the main surface of the substrate. A terahertz device according to any one of appendices E1 to E3.

[0324] (Appendix E5) a support substrate having a substrate main surface; a waveguide mounted on the main surface of the substrate and having a transmission region for transmitting the electromagnetic wave; Equipped with the terahertz element is mounted on the substrate main surface so that the element main surface faces the same side as the substrate main surface within the transmission region; The reflector is provided on the waveguide on a side opposite to a side on which the support substrate is disposed. A terahertz device according to any one of appendices E1 to E3.

[0325] (Appendix E6) the reflector and the waveguide are formed separately, The reflector is attached to the waveguide. 1. A terahertz device as described in Appendix E5.

[0326] (Appendix E7) The reflector is detachably attached to the waveguide. 1. A terahertz device as described in Appendix E6.

[0327] (Appendix E8) the waveguide has a through hole that penetrates the waveguide in the thickness direction and forms the transmission region, the terahertz element is disposed in the through hole, The reflecting surface is provided so as to cover the entire through hole when viewed from the thickness direction. A terahertz device according to any one of appendices E5 to E7.

[0328] (Appendix E9) The inner surface of the through hole faces from the support substrate to the reflector. The tapered surfaces move apart as the When viewed from the thickness direction, the reflecting surface covers the entire area extending from the tapered surface along the tapered surface in the thickness direction. 1. A terahertz device as described in Appendix E8.

[0329] (Appendix E10) a support substrate having a substrate main surface; the terahertz element is mounted on the substrate main surface so that the element main surface faces the same side as the substrate main surface; The reflector is mounted on the main surface of the substrate. A terahertz device according to any one of appendices E1 to E3.

[0330] (Appendix E11) a support substrate having a substrate main surface and a substrate back surface facing opposite to each other in the thickness direction; the terahertz element is mounted on the main surface of the substrate, An exterior terminal electrically connected to the terahertz element is provided on the rear surface of the substrate. A terahertz device according to any one of appendices E1 to E3.

[0331] (Appendix E12) a plurality of the terahertz elements are provided, The reflector is provided so as to cover the element principal surfaces of the plurality of terahertz elements in the thickness direction. A terahertz device according to any one of appendices E1 to E3.

[0332] (Appendix E13) a support substrate having a substrate main surface; each of the plurality of terahertz elements is mounted on the substrate main surface so that the element main surface faces the same side as the substrate main surface, and has a main electrode and a ground electrode; a power supply line electrically connected to each of the terahertz elements is provided on a main surface of the substrate; The power supply line includes a plurality of main conductors electrically connected to the main electrodes of the plurality of terahertz elements individually, and a ground conductor electrically connected in common to the ground electrodes of the plurality of terahertz elements. 1. A terahertz device as described in Appendix E12.

[0333] (Appendix E14) The reflector is made of a conductive material that is non-transparent to the electromagnetic waves. A terahertz device according to any one of appendices E1 to E13.

[0334] (Appendix E15) the reflector is made of a material that is transparent to the electromagnetic wave, The reflecting surface is formed with a conductive film made of a conductive material that is non-transparent to the electromagnetic waves. A terahertz device according to any one of appendices E1 to E13.

[0335] (Appendix E16) a terahertz element having a main surface and a back surface facing the opposite side to the main surface, the main surface having a receiving point for receiving electromagnetic waves in the terahertz band and a detecting point for detecting the electromagnetic waves, and the thickness direction of the terahertz element being perpendicular to the main surface; a reflector having an opening that opens in a direction intersecting the thickness direction and a reflecting surface that is arranged at a position facing the element main surface with an interval in the thickness direction, The reflecting surface reflects electromagnetic waves propagating from the outside of the terahertz device through the opening in a direction toward the terahertz element. Terahertz device. [Explanation of symbols]

[0336] 10... Terahertz device, 20... Support substrate, 21... Substrate main surface, 22... Substrate back surface, 27... Power supply line, 27a... Main conductor, 27b, 27c... Ground conductor, 28... Exterior terminal, 30... Waveguide, 37... Through hole, 37a... Tapered surface, 38... Transmission region, 40... Reflector, 40A... Opening, 47a... Reflecting surface, 47b... Tip portion, 47c... Base end portion, 47e... Conductive film, 50... Terahertz element, 51... Element main surface, 52... Element Back surface, 62...active element, 63c...first pad electrode (main electrode), 64c...second pad electrode (ground electrode), 80...support substrate, 81...main surface of substrate, 82...back surface of substrate, 88...power supply line, 88A...main conductor, 88C...ground conductor, 90...reflector, 97...opening, 98...reflecting surface, 98a...tip portion, 98b...base end portion, 100...waveguide, 130...short-circuit portion, 137...back-short portion, P1...oscillation point, P2...radiation point.

Claims

1. a terahertz element having a main surface and a back surface facing the opposite side to the main surface, emitting electromagnetic waves in the terahertz band, and having a thickness direction perpendicular to the main surface; a reflector that is disposed at a position facing the element main surface at an interval in the thickness direction and has a reflection surface that reflects the electromagnetic waves emitted by the terahertz element in the thickness direction in a direction intersecting the thickness direction, Terahertz device.

2. The terahertz element has an active element that converts the electromagnetic wave into electrical energy at an oscillation point where the electromagnetic wave in the terahertz band is oscillated. The terahertz device according to claim 1 .

3. the terahertz element is connected to the active element and includes an antenna that radiates the electromagnetic wave in a direction perpendicular to the element main surface and toward the reflecting surface. The terahertz device according to claim 2 .

4. the active element is any one of a resonant tunneling diode, a Tannet diode, an in-pad diode, a GaAs-based field effect transistor, a GaN-based FET, a high electron mobility transistor, and a heterojunction bipolar transistor; The terahertz device according to claim 2 .

5. The antenna is one of a dipole antenna, a bowtie antenna, a slot antenna, a patch antenna, and a ring antenna. The terahertz device according to claim 3 .

6. a support substrate having a substrate main surface; the terahertz element is mounted on the substrate main surface so that the element main surface faces the same side as the substrate main surface; a transmission line connected to the terahertz element is provided on the main surface of the substrate; The terahertz device according to any one of claims 1 to 5.

7. the terahertz element is connected to the transmission line by a wire; The terahertz device according to claim 6 .

8. the terahertz element is connected to the transmission line by a bump; The terahertz device according to claim 6 .

9. the transmission line is any one of a coplanar line, a microstrip line, a strip line, and a slot line; The terahertz device according to any one of claims 6 to 8.

10. a support substrate having a substrate main surface on which the terahertz element is mounted; a waveguide mounted on the main surface of the substrate and having a transmission region for transmitting the electromagnetic wave; The terahertz element is The element has an oscillation point for oscillating the electromagnetic wave and a radiation point for radiating the electromagnetic wave on the main surface thereof, and The radiation point is positioned at the center of the transmission area. The terahertz device according to any one of claims 1 to 9.

11. a support substrate having a substrate main surface; a waveguide mounted on the main surface of the substrate and having a transmission region for transmitting the electromagnetic wave; the terahertz element is mounted on the substrate main surface so that the element main surface faces the same side as the substrate main surface within the transmission region; the reflector is provided on the waveguide on a side opposite to a side on which the support substrate is disposed with respect to the waveguide, the waveguide includes a conductive material that is non-transparent to the electromagnetic wave; The terahertz device according to any one of claims 1 to 10.

12. a support substrate having a substrate main surface; a waveguide mounted on the main surface of the substrate and having a transmission region for transmitting the electromagnetic wave; the reflector is provided on the waveguide on a side opposite to a side on which the support substrate is disposed with respect to the waveguide, the waveguide has a through hole that penetrates the waveguide in the thickness direction and forms the transmission region, and includes a material that is transparent to the electromagnetic wave; the terahertz element is mounted on the substrate main surface so that the element main surface faces the same side as the substrate main surface within the through hole in the transmission region, an inner surface of the through hole is provided with a conductive film containing a conductive material that is non-transparent to the electromagnetic waves; The terahertz device according to any one of claims 1 to 10.

13. a reflecting portion that reflects the electromagnetic wave on the rear surface side of the terahertz element; The terahertz device according to any one of claims 1 to 12.

14. a support substrate having a substrate main surface; a waveguide mounted on the support substrate and having a transmission region for transmitting the electromagnetic wave; the terahertz element is mounted on the substrate main surface so that the element main surface faces the same side as the substrate main surface within the transmission region; the waveguide includes a main body portion that constitutes the transmission region and a short-circuit portion that short-circuits one end side of the transmission region, the reflecting portion is a bottom surface of a recess provided in the short-circuit portion, 14. The terahertz device of claim 13.

15. a support substrate having a substrate main surface; a waveguide mounted on the main surface of the substrate and having a transmission region for transmitting the electromagnetic wave; the terahertz element is mounted on the substrate main surface so that the element main surface faces the same side as the substrate main surface within the transmission region; the reflector is detachably attached to the waveguide on a side opposite to a side on which the support substrate is disposed with respect to the waveguide, the reflector has a step portion that abuts against the waveguide in the thickness direction. The terahertz device according to any one of claims 1 to 10.

16. a support substrate having a substrate main surface on which the terahertz element is mounted; a waveguide mounted on the main surface of the substrate and having a transmission region for transmitting the electromagnetic wave; the reflector is provided on the waveguide on a side opposite to a side on which the support substrate is disposed with respect to the waveguide, the waveguide has a through hole that penetrates the waveguide in the thickness direction and forms the transmission region, the terahertz element is mounted on the substrate main surface so that the element main surface faces the same side as the substrate main surface within the through hole in the transmission region, a base end portion of the reflecting surface that is an end portion closer to the waveguide is disposed at the same position as an inner surface that constitutes the through hole or outward from the inner surface when viewed from the thickness direction; The terahertz device according to any one of claims 1 to 10.

Images