A terahertz horn antenna and a method for manufacturing the same

Abstract

The present application provides a terahertz horn antenna and a preparation method thereof, and relates to the technical field of mobile communication systems. The antenna layer is set as an antenna layer with a horn antenna groove structure. Due to the advantages of the horn antenna itself, the terahertz horn antenna has the advantages of simple structure, easy gain control, excellent frequency characteristics, low loss, etc. In addition, the antenna layer and the radio frequency layer provided by the present application are fixed by bonding with the radiation electrode and the metal film, which not only realizes a low-reflection interconnection channel, but also can confine the THz wave within the bonding area, avoiding the problem of electromagnetic leakage caused by the stacking of the antenna layer and the radio frequency layer, and improving the performance of the terahertz horn antenna. The present application provides that both the antenna layer and the radio frequency layer adopt a glass substrate. The glass substrate has the advantages of high mechanical strength and low dielectric loss, and the glass substrate can withstand higher temperatures, thereby reducing the problem of substrate warping and deformation, and thus can improve the preparation quality of the terahertz horn antenna.

Description

Technical Field

[0001] The present application relates to the technical field of mobile communication systems, and more specifically, to a terahertz horn antenna and a method for preparing the same. Background Art

[0002] Terahertz (THz) waves refer to electromagnetic waves with frequencies between 0.1 and 10 THz. They represent the transition zone between macroscopic classical theory and microscopic quantum theory, known as the "THz gap" of the electromagnetic spectrum. THz technology has broad applications in radar, remote sensing, homeland security and counterterrorism, highly secure data communications and transmission, atmospheric and environmental monitoring, real-time bioinformatics extraction, and medical diagnostics. Therefore, THz research holds significant application value for the national economy and national security, and THz antennas are a major research priority for researchers today. Summary of the Invention

[0003] In view of this, the present application provides a terahertz horn antenna and a preparation method thereof, which effectively solve the technical problems existing in the prior art. The terahertz horn antenna has the advantages of simple structure, easy gain control, excellent frequency characteristics, and low loss. At the same time, it avoids the problem of electromagnetic leakage and improves the performance of the terahertz horn antenna.

[0004] To achieve the above objectives, the technical solutions provided by this application are as follows:

[0005] A terahertz horn antenna, comprising:

[0006] An antenna layer, the antenna layer comprising: a first glass substrate, the first glass substrate comprising a first surface and a second surface opposite to each other; at least one cavity, the cavity penetrating the first glass substrate from the first surface to the second surface, the cavity comprising a horn antenna groove located on one side of the first surface and a waveguide opening located on one side of the second surface; and a metal film, the metal film covering at least the first surface, the second surface, and an inner wall of the cavity;

[0007] A radio frequency layer, the radio frequency layer comprising: a second glass substrate, the second glass substrate comprising a third surface and a fourth surface opposite to each other, the third surface being opposite to the second surface; a terahertz chip, the terahertz chip being fixed in the second glass substrate; a radiation electrode, the radiation electrode being located on one side of the third surface and corresponding to the waveguide opening, the radiation electrode being bonded to a portion of the metal film around the waveguide opening; an interconnection line, the interconnection line being located on the fourth surface and electrically connected to the terahertz chip; and a signal transmission line, the signal transmission line penetrating the second glass substrate in a direction from the third surface to the fourth surface, and the signal transmission line being electrically connected to both the radiation electrode and the interconnection line.

[0008] Optionally, the signal transmission line includes:

[0009] at least one inner conductive via;

[0010] and a plurality of outer conductive through-holes arranged around the at least one inner conductive through-hole, wherein the inner conductive through-holes and the outer conductive through-holes both penetrate the second glass substrate in a direction from the third surface to the fourth surface;

[0011] The inner conductive via and the plurality of outer conductive vias form a substrate-integrated coaxial line structure.

[0012] Optionally, the radiation electrode includes:

[0013] a matching electrode, the matching electrode being electrically connected to the inner conductive through hole and located within the range of the waveguide opening;

[0014] and a ground electrode surrounding the matching electrode, wherein the ground electrode is electrically connected to the outer conductive via, and the ground electrode is bonded to a portion of the metal film around the waveguide opening.

[0015] Optionally, the signal transmission line includes:

[0016] a first conductive via row and a second conductive via row disposed opposite to each other;

[0017] The first conductive via in the first conductive via row and the second conductive via in the second conductive via row both penetrate the second glass substrate along a direction from the third surface to the fourth surface;

[0018] The first conductive via row and the second conductive via row form a substrate integrated waveguide structure.

[0019] Optionally, the radiation electrode includes a coupling slot, and the coupling slot is located within the range of the waveguide opening.

[0020] Optionally, the waveguide opening is a rectangular waveguide opening.

[0021] Optionally, the radio frequency layer includes a heat dissipation opening on one side of the fourth surface, and the heat dissipation opening exposes at least a portion of the surface of the terahertz chip.

[0022] Based on the same inventive concept, the present application also provides a method for preparing a terahertz horn antenna, which is used to prepare the above-mentioned terahertz horn antenna. The preparation method includes:

[0023] preparing an antenna layer and a radio frequency layer;

[0024] Aligning and fixing the antenna layer and the radio frequency layer;

[0025] The antenna layer includes: a first glass substrate, the first glass substrate including a first surface and a second surface facing each other; at least one cavity, the cavity penetrating the first glass substrate from the first surface to the second surface, the cavity including a horn antenna groove located on one side of the first surface and a waveguide opening located on one side of the second surface; and a metal film, the metal film covering at least the first surface, the second surface, and the inner wall of the cavity;

[0026] The radio frequency layer includes: a second glass substrate, the second glass substrate includes a third surface and a fourth surface opposite to each other, the third surface and the second surface being opposite to each other; a terahertz chip, the terahertz chip being fixed in the second glass substrate; a radiation electrode, the radiation electrode being located on one side of the third surface and corresponding to the waveguide opening, the radiation electrode being bonded to a portion of the metal film around the waveguide opening; an interconnection line, the interconnection line being located on the fourth surface and electrically connected to the terahertz chip; and a signal transmission line, the signal transmission line passing through the second glass substrate in a direction from the third surface to the fourth surface, and the signal transmission line being electrically connected to both the radiation electrode and the interconnection line.

[0027] Optionally, the method for preparing the antenna layer includes:

[0028] Etching the first glass substrate to form at least one cavity, the cavity penetrating the first glass substrate from the first surface to the second surface, the cavity comprising a horn antenna groove located on one side of the first surface and a waveguide opening located on one side of the second surface;

[0029] The metal film is formed, and the metal film at least covers the first surface, the second surface and the inner wall of the cavity.

[0030] Optionally, the method for preparing the radio frequency layer includes:

[0031] On one side of the fourth surface, etching the second glass substrate to form a plurality of blind holes and chip grooves;

[0032] Filling the blind hole with conductive metal to form the signal transmission line, and forming a grounding metal layer on the inner wall of the chip groove;

[0033] Fixing the terahertz chip in the chip groove;

[0034] bonding a temporary substrate to one side of the fourth surface;

[0035] On one side of the third surface, the second glass substrate is thinned to expose the signal transmission line;

[0036] forming the radiation electrode on the third surface, wherein the radiation electrode is electrically connected to the signal transmission line;

[0037] The temporary substrate is removed, and the interconnection circuit is formed on the fourth surface, wherein the interconnection circuit is electrically connected to both the terahertz chip and the signal transmission line.

[0038] Compared with the existing technology, the technical solution provided by this application has at least the following advantages:

[0039] The present application provides a terahertz horn antenna and a preparation method thereof, the terahertz horn antenna comprising: an antenna layer, the antenna layer comprising: a first glass substrate, the first glass substrate comprising a first surface and a second surface opposite to each other; at least one cavity, the cavity penetrating the first glass substrate from the first surface to the second surface, the cavity comprising a horn antenna groove located on one side of the first surface and a waveguide opening located on one side of the second surface; a metal film, the metal film covering at least the first surface, the second surface and the inner wall of the cavity; a radio frequency layer comprising: a second glass substrate, the second glass substrate comprising a first surface and a second surface opposite to each other; a third surface and a fourth surface thereof, the third surface being opposite to the second surface; a terahertz chip, the terahertz chip being fixed in the second glass substrate; a radiation electrode, the radiation electrode being located on one side of the third surface and corresponding to the waveguide opening, the radiation electrode being bonded to a portion of the metal film around the waveguide opening; an interconnection line, the interconnection line being located on the fourth surface and electrically connected to the terahertz chip; a signal transmission line, the signal transmission line passing through the second glass substrate in a direction from the third surface to the fourth surface, and the signal transmission line being electrically connected to both the radiation electrode and the interconnection line.

[0040] As can be seen from the above content, the technical solution provided by the present application sets the antenna layer as an antenna layer with a horn antenna groove structure. Due to the advantages of the horn antenna itself, the terahertz horn antenna has the advantages of simple structure, easy control of gain, excellent frequency characteristics, low loss, etc. In addition, the antenna layer and the radio frequency layer provided by the present application are fixed by bonding the radiation electrode and the metal film, which not only realizes a low-reflection interconnection channel, but also can confine the THz wave to the bonding area, avoiding the problem of electromagnetic leakage caused by the stacking of the antenna layer and the radio frequency layer, and improving the performance of the terahertz horn antenna. In addition, the present application provides that both the antenna layer and the radio frequency layer adopt a glass substrate. The glass substrate has the advantages of high mechanical strength and low dielectric loss, and the glass substrate can withstand higher temperatures, thereby reducing the problem of substrate warping and deformation, and thus can improve the preparation quality of the terahertz horn antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0042] Figure 1 A schematic structural diagram of a terahertz horn antenna provided in an embodiment of the present application;

[0043] Figure 2 A schematic structural diagram of another terahertz horn antenna provided in an embodiment of the present application;

[0044] Figure 3 A schematic structural diagram of another terahertz horn antenna provided in an embodiment of the present application;

[0045] Figure 4 A top view of a radiation electrode provided in an embodiment of the present application;

[0046] Figure 5 A top view of another radiation electrode provided in an embodiment of the present application;

[0047] Figure 6 A schematic structural diagram of another terahertz horn antenna provided in an embodiment of the present application;

[0048] Figure 7 A top view of another radiation electrode provided in an embodiment of the present application;

[0049] Figures 8a to 8c Schematic diagram of the structures of three coplanar waveguide transition structures provided in the embodiments of the present application;

[0050] Figure 9 A flowchart of a method for preparing a terahertz horn antenna provided in an embodiment of the present application;

[0051] Figures 10a to 10b Schematic diagram of the corresponding structure of the preparation steps of the antenna layer provided in the embodiment of the present application;

[0052] Figures 11a to 11g This is a schematic diagram of the corresponding structures of the preparation steps of the radio frequency layer provided in an embodiment of the present application. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0054] As mentioned in the background, terahertz (THz) waves refer to electromagnetic waves with frequencies between 0.1 and 10 THz. They represent the transition zone between macroscopic classical theory and microscopic quantum theory, known as the "THz gap" of the electromagnetic spectrum. THz technology has broad applications in radar, remote sensing, homeland security and counterterrorism, highly secure data communications and transmission, atmospheric and environmental monitoring, real-time bioinformatics extraction, and medical diagnostics. Therefore, THz research has significant application value to the national economy and national security, and THz antennas are currently a major research topic for researchers.

[0055] Specifically, 6G is a more advanced next-generation mobile communication system, boasting transmission rates and bandwidth that are expected to increase 10-100 times compared to 5G. Therefore, 6G communication systems must utilize the terahertz frequency band to achieve ultra-high transmission rates and ultra-large bandwidth. This places high demands on the integrated structure, such as low-loss AiP (antenna-in-package) antennas, low-reflection matching interconnects, low-loss material systems, and high-precision fabrication processes. Existing terahertz antenna research faces several major challenges. First, traditional antenna structures such as microstrip patch antennas and slot antennas suffer from narrow bandwidth, low power handling, and high loss in the terahertz frequency band, and the substrate material significantly impacts antenna performance. Second, transmitting signals from the RF chip to the horn antenna presents another challenge. Conventional 3D integration solutions utilize vertical interconnect structures, such as ball grid arrays (BGAs), which exhibit significant electromagnetic leakage at high frequencies and result in significant reflections. Third, in terms of integration process and material system, although conventional organic sheets have low costs, they have large dielectric losses (the higher the frequency, the greater the loss), relatively low processing accuracy, and a thermal expansion coefficient that does not match that of silicon-based chips. Long-term use may cause chip deformation and is no longer suitable for the terahertz band.

[0056] Based on this, the embodiments of the present application provide a terahertz horn antenna and a preparation method thereof, which effectively solve the technical problems existing in the prior art. The terahertz horn antenna has the advantages of simple structure, easy gain control, excellent frequency characteristics, and low loss. At the same time, it avoids the problem of electromagnetic leakage and improves the performance of the terahertz horn antenna.

[0057] To achieve the above purpose, the technical solutions provided in the embodiments of the present application are as follows, specifically combined with Figures 1 to 11gThe technical solutions provided in the embodiments of the present application are described in detail.

[0058] refer to Figure 1 FIG. 1 is a schematic diagram of the structure of a terahertz horn antenna provided in an embodiment of the present application, wherein the terahertz horn antenna includes:

[0059] The antenna layer includes: a first glass substrate 110, wherein the first glass substrate 110 includes a first surface and a second surface that are opposite to each other; at least one cavity, wherein the cavity extends through the first glass substrate 110 from the first surface to the second surface, and wherein the cavity includes a horn antenna groove 121 located on one side of the first surface and a waveguide opening 122 located on one side of the second surface; and a metal film 130, wherein the metal film 130 covers at least the first surface, the second surface, and the inner wall of the cavity.

[0060] The radio frequency layer includes: a second glass substrate 210, the second glass substrate 210 includes a third surface and a fourth surface opposite to each other, the third surface and the second surface being opposite to each other; a terahertz chip 220, the terahertz chip 220 being fixed in the second glass substrate 210; a radiation electrode 230, the radiation electrode 230 being located on one side of the third surface and corresponding to the waveguide opening 122, the radiation electrode 230 being bonded to a portion of the metal film 130 around the waveguide opening 122; an interconnection line 240, the interconnection line 240 being located on the fourth surface and electrically connected to the terahertz chip 220; and a signal transmission line 250, the signal transmission line 250 penetrating the second glass substrate 210 in a direction from the third surface to the fourth surface, and the signal transmission line 250 being electrically connected to both the radiation electrode 230 and the interconnection line 240.

[0061] It is understandable that in the terahertz chip provided in the embodiment of the present application, the antenna layer is configured as an antenna layer having a horn antenna groove 121 structure. Due to the inherent advantages of the horn antenna, the terahertz horn antenna has advantages such as a simple structure, easy gain control, excellent frequency characteristics, and low loss. In addition, the antenna layer and the radio frequency layer provided in the embodiment of the present application are fixed by bonding the radiation electrode 230 and the metal film 130. A planar bonding process is adopted, eliminating existing interconnect structures such as BGA. This not only realizes a low-reflection interconnect channel, but also can confine THz waves to the bonding area, avoiding the problem of electromagnetic leakage caused by the stacking of the antenna layer and the radio frequency layer, and improving the performance of the terahertz horn antenna. In addition, the embodiment of the present application provides that both the antenna layer and the radio frequency layer use a glass substrate. Glass substrates have advantages such as high mechanical strength, low dielectric loss, and easier flattening. Glass substrates can not only withstand higher temperatures, but also make packaging and photolithography easier, thereby reducing the problems of substrate warping and deformation, and thus can improve the preparation quality of the terahertz horn antenna.

[0062] Continue to refer Figure 1 As shown, the horn antenna groove 121 provided in the embodiment of the present application can be formed by etching the first glass substrate 110 using a laser etching process. In practice, since it is impossible to etch an ideally smooth inner wall on a glass substrate, the inner wall of the horn antenna groove 121 provided in the embodiment of the present application is formed in a multi-stepped shape to approximate an ideally smooth, inclined inner wall. A horn antenna (i.e., a horn antenna groove) is formed by gradually expanding a waveguide, which has advantages such as good frequency characteristics, low loss, low input standing wave ratio, and wide bandwidth. The horn antenna groove 121 provided in the embodiment of the present application can be formed by gradually expanding a rectangular waveguide or a circular waveguide. Under the same main mode range, a rectangular waveguide has a smaller volume, and the expanded horn antenna groove 121 is also more compact. Especially in the high frequency band, it is easier to meet the λ / 2 spacing requirement of a phased antenna array. Therefore, when constructing a horn antenna array in the terahertz frequency band, a horn antenna expanded from a rectangular waveguide is selected as an array element. That is, the waveguide opening 122 provided in the embodiment of the present application is preferably a rectangular waveguide opening.

[0063] In one embodiment of the present application, the second glass substrate 210 provided in the embodiment of the present application has a chip groove on the fourth surface side, and the terahertz chip 220 is fixedly arranged in the chip groove. In order to facilitate the grounding of the terahertz chip 220, a grounding metal layer 260 is also provided in the chip groove. Figure 1As shown, the terahertz chip 220 provided in the embodiment of the present application can be a III-V group chip. Since the III-V group chip has the characteristic of a back electrode, the grounding metal layer 260 provided in the embodiment of the present application at least covers the bottom of the chip groove. The back electrode of the terahertz chip 220 can be electrically connected to the grounding metal layer 260 through the conductive structure 221; wherein the conductive structure 221 can be a conductive material such as conductive glue, solder, etc., and this application does not make specific restrictions on this. Or refer to Figure 2 As shown, it is a structural schematic diagram of another terahertz horn antenna provided in an embodiment of the present application, wherein the terahertz chip 220 can be a silicon-based chip, in which case the grounding metal layer 260 at least covers the side walls of the chip groove, and the silicon-based chip 220 can be electrically connected to the grounding metal layer 260 on the side wall through an external electrode 222.

[0064] Furthermore, the terahertz horn antenna provided in this embodiment of the application also includes a ball-bearing structure 270 electrically connected to the interconnection circuit 240 to facilitate external connection of the terahertz horn antenna. Furthermore, the RF layer provided in this embodiment of the application includes a heat dissipation opening 280 on one side of the fourth surface. These heat dissipation openings 280 expose at least a portion of the surface of the terahertz chip 220, thereby improving the heat dissipation of the terahertz chip 220, reducing the probability of damage to the terahertz chip 220, and ensuring a long service life for the terahertz horn antenna.

[0065] It should be noted that the terahertz chip 220 provided in the embodiment of the present application is fixedly mounted within the chip recess. To prevent short circuits between the terahertz chip 220 and the ground metal layer 260, an insulating material is also filled between the terahertz chip 220 and the ground metal layer 260. Furthermore, when the interconnection circuit 240 provided in the embodiment of the present application comprises a single-layer circuit, it can be formed directly on the fourth surface of the second glass substrate 210 and protected by a covering of insulating material. Alternatively, when the interconnection circuit 240 provided in the embodiment of the present application comprises multiple layers of circuits, adjacent circuit layers can be isolated by insulating material to prevent short circuits between the circuits. Similarly, the radiating electrode 230 provided in the embodiment of the present application can be formed directly on the third surface of the second glass substrate 210 and electrically connected to the signal transmission line 250. Alternatively, an insulating material layer can be formed on the third surface of the second glass substrate 210, and the radiating electrode 230 can be formed on the insulating material layer. This application does not impose any specific limitations on this.

[0066] The metal film 130 provided in the embodiment of the present application can be a gold metal film, which is not specifically limited in this application. To improve the bonding strength between the gold metal film 130 and the first glass substrate 110, a titanium layer can be provided between the gold metal film 130 and the first glass substrate 110. Furthermore, at least one of the radiation electrode 230, the interconnection line 240, and the signal transmission line 250 can also be made of gold. When a line segment of the radiation electrode 230, the interconnection line 240, or the signal transmission line 250 is in direct contact with the second glass substrate 210, a titanium layer can be provided between the gold line segment and the second glass substrate 210 to improve the bonding strength between the gold line segment and the second glass substrate 210.

[0067] In one embodiment of the present application, the signal transmission line 250 provided in the embodiment of the present application may be a transmission line with a coaxial structure. Figures 3 to 5 As shown, Figure 3 This is a structural diagram of another terahertz horn antenna provided in an embodiment of the present application. Figure 4 A top view of a radiation electrode provided in an embodiment of the present application, Figure 5 A top view of another radiating electrode provided in an embodiment of the present application. The signal transmission line 250 provided in this embodiment of the present application includes: at least one inner conductive via 251; and multiple outer conductive vias 252 disposed around the at least one inner conductive via 251. Both the inner conductive via 251 and the outer conductive vias 252 penetrate the second glass substrate 210 from the third surface to the fourth surface. The inner conductive via 251 and the multiple outer conductive vias 252 form a substrate-integrated coaxial line structure.

[0068] It can be understood that the coaxial line is a dual-conductor transmission line consisting of a coaxial inner conductor and an outer conductor. The outer conductor of the coaxial line is grounded, and the electromagnetic field is confined between the inner and outer conductors. Therefore, the coaxial line has basically no radiation loss and is almost not affected by external signal interference. The signal transmission line provided in the embodiment of the present application uses a metallized inner conductive through hole 251 to replace the inner conductor, and a metallized outer conductive through hole 252 to replace the outer conductor. Specifically combined Figure 4 As shown, the signal transmission line 250 provided in the embodiment of the present application may include an inner conductive through-hole 251 and a plurality of outer conductive through-holes 252 arranged around the inner conductive through-hole 251, the diameter of the inner conductive through-hole 251 is larger than the diameter of the outer conductive through-hole 252, and the inner conductive through-hole 251 and the outer conductive through-hole 252 constitute a substrate-integrated coaxial line structure.

[0069] Furthermore, in order to prevent electromagnetic waves from leaking from the gaps between the outer conductive vias 232 and to enhance the shielding capability of the outer conductive vias 252, the outer conductive vias 252 may be arranged in multiple circles around the inner conductive vias 251. Figure 5 As shown, the outer conductive through-hole 252 provided in the embodiment of the present application is arranged in multiple circles around the inner conductive through-hole 251; in addition, considering the process consistency, the diameter of the inner conductive through-hole 251 provided in the embodiment of the present application is prepared to be consistent with the diameter of the outer conductive through-hole 252, and the number of the inner conductive through-holes 251 is prepared as a plurality of conductive through-holes arranged along the annular direction, and the present application does not make specific restrictions on this.

[0070] Continue to refer Figure 4 and Figure 5 As shown, in order to reduce reflection of the transmission structure, a coaxial-waveguide opening converter is required to transmit the signal from the conductive through-hole of the substrate-integrated coaxial line structure to the horn antenna to reduce its insertion loss, thereby optimizing the design of the radiation electrode 230. The radiation electrode 230 provided in the embodiment of the present application includes: a matching electrode 231, which is electrically connected to the inner conductive through-hole 251 and is located within the range of the waveguide opening 122; and a grounding electrode 232 surrounding the matching electrode 231, which is electrically connected to the outer conductive through-hole 252 and is bonded to the portion of the metal film 130 around the waveguide opening 122. The signal provided by the embodiment of the present application is emitted from the terahertz chip 220 and transmitted to the substrate integrated coaxial line structure through the interconnection line 240, wherein the inner conductive through-hole 251 is connected to the signal line in the interconnection line 240, and the outer conductive through-hole 252 is connected to the ground line in the interconnection line 240, and then the signal is transmitted to the antenna layer through the through-holes of the matching electrode 231 and the ground electrode 232.

[0071] The signal transmission line 250 provided in the embodiment of the present application can also be a transmission line of a similar integrated waveguide structure. Figure 6 and Figure 7 As shown, Figure 6 This is a structural diagram of another terahertz horn antenna provided in an embodiment of the present application. Figure 7This is a top view of another radiation electrode provided in an embodiment of the present application. The signal transmission line 250 provided in the embodiment of the present application includes: a first conductive through-hole row and a second conductive through-hole row arranged opposite to each other; the first conductive through-hole 253 in the first conductive through-hole row and the second conductive through-hole 254 in the second conductive through-hole row both penetrate the second glass substrate 210 in the direction from the third surface to the fourth surface; the first conductive through-hole row and the second conductive through-hole row form a substrate integrated waveguide structure. Furthermore, in order to couple the radio frequency signal of the signal transmission line 250 of the substrate integrated waveguide structure to the antenna layer, the radiation electrode 230 provided in the embodiment of the present application includes a coupling slot 233, and the coupling slot 233 is located within the range of the waveguide opening 122, and the coupling slot 233 is misaligned with the central axis of the substrate integrated waveguide structure.

[0072] It should be noted that the radio frequency layer of the terahertz horn antenna provided in the embodiment of the present application is a closed transmission structure. When the radio frequency layer of the terahertz horn antenna is connected to the external circuit, the connection can be achieved through a coplanar waveguide transition structure. Common coplanar waveguide transition structures are as follows: Figures 8a to 8c As shown, this is the same as the prior art, so no unnecessary details are given.

[0073] Based on the same inventive concept, the present application also provides a method for preparing a terahertz horn antenna, which is used to prepare the terahertz horn antenna provided in any of the above embodiments. Figure 9 FIG. 1 is a flow chart of a method for preparing a terahertz horn antenna according to an embodiment of the present application, wherein the method for preparing the terahertz horn antenna according to an embodiment of the present application includes:

[0074] S1. Prepare the antenna layer and the radio frequency layer.

[0075] S2. Align and fix the antenna layer and the radio frequency layer, wherein a planar bonding process is used to bond the radiation electrode to a portion of the metal film around the waveguide opening.

[0076] The antenna layer includes: a first glass substrate, the first glass substrate including a first surface and a second surface facing each other; at least one cavity, the cavity penetrating the first glass substrate from the first surface to the second surface, the cavity including a horn antenna groove located on one side of the first surface and a waveguide opening located on one side of the second surface; and a metal film, the metal film covering at least the first surface, the second surface, and the inner wall of the cavity;

[0077] The radio frequency layer includes: a second glass substrate, the second glass substrate includes a third surface and a fourth surface opposite to each other, the third surface and the second surface being opposite to each other; a terahertz chip, the terahertz chip being fixed in the second glass substrate; a radiation electrode, the radiation electrode being located on one side of the third surface and corresponding to the waveguide opening, the radiation electrode being bonded to a portion of the metal film around the waveguide opening; an interconnection line, the interconnection line being located on the fourth surface and electrically connected to the terahertz chip; and a signal transmission line, the signal transmission line passing through the second glass substrate in a direction from the third surface to the fourth surface, and the signal transmission line being electrically connected to both the radiation electrode and the interconnection line.

[0078] Specific combination Figures 10a to 10b As shown, Figures 10a to 10b The method for preparing the antenna layer provided in the embodiment of the present application includes:

[0079] like Figure 10a As shown, the first glass substrate 110 is etched to form at least one cavity, which passes through the first glass substrate 110 along the direction from the first surface to the second surface. The cavity includes a horn antenna groove 121 located on one side of the first surface and a waveguide opening 122 located on one side of the second surface.

[0080] Optionally, the first glass substrate 110 can be etched using a laser induced etching process to form a horn antenna groove 121 and a waveguide opening 122 on the first glass substrate 110. Since it is impossible to etch a smooth and ideal smooth inner wall on a glass substrate, the inner wall of the horn antenna groove 121 provided in the embodiment of the present application is in a multi-step shape to approximate an ideal smooth inclined inner wall.

[0081] like Figure 10b As shown, the metal film 130 is formed, and the metal film 130 at least covers the first surface, the second surface and the inner wall of the cavity. The metal film 130 can be formed based on a wafer-level planar process and an electroplating process.

[0082] Combine Figures 11a to 11g As shown, Figures 11a to 11g The method for preparing the radio frequency layer provided in the embodiment of the present application includes:

[0083] like Figure 11a As shown, on one side of the fourth surface, the second glass substrate 210 is etched to form a plurality of blind holes 250a and chip grooves 250b.

[0084] like Figure 11b As shown, the blind hole 250a is filled with conductive metal to form the signal transmission line 250, and a grounding metal layer 260 is formed on the inner wall of the chip groove 250b.

[0085] like Figure 11c As shown, the terahertz chip 220 is fixed in the chip groove 250b. Optionally, the embodiment of the present application can use glass wafer low warpage chip embedding technology to achieve the embedding of the terahertz chip 220. For example, when the terahertz chip 220 is a Group III-V chip, the back electrode of the terahertz chip 220 can be electrically connected to the ground metal layer 260 through the conductive structure 221.

[0086] like Figure 11d As shown, a temporary substrate 300 is bonded to one side of the fourth surface.

[0087] like Figure 11e As shown, on the third surface side, the second glass substrate 210 is thinned to expose the signal transmission line 250 .

[0088] like Figure 11f As shown, the radiation electrode 230 is formed on the third surface, and the radiation electrode 230 is electrically connected to the signal transmission line 250 .

[0089] like Figure 11g As shown, the temporary substrate 300 is removed, and the interconnection line 240 is formed on the fourth surface. The interconnection line 240 is electrically connected to the terahertz chip 220 and the signal transmission line 250. Preferably, the interconnection line 240 reserves a heat dissipation opening 280 to expose at least part of the surface of the terahertz chip 220.

[0090] After the antenna layer and the RF layer are prepared, a low-temperature metal interlayer planar bonding process is used to achieve bonding between the antenna layer and the RF layer, so as to bond the radiation electrode 230 to the portion of the metal film 130 around the waveguide opening 122; finally, a ball planting structure 270 is fabricated on the side of the interconnection line 240 away from the RF layer to complete the preparation of the terahertz horn antenna.

[0091] The embodiment of the present application provides a terahertz horn antenna and a preparation method thereof, the terahertz horn antenna comprising: an antenna layer, the antenna layer comprising: a first glass substrate, the first glass substrate comprising a first surface and a second surface opposite to each other; at least one cavity, the cavity penetrating the first glass substrate from the first surface to the second surface, the cavity comprising a horn antenna groove located on one side of the first surface and a waveguide opening located on one side of the second surface; a metal film, the metal film covering at least the first surface, the second surface and the inner wall of the cavity; a radio frequency layer, the radio frequency layer comprising: a second glass substrate, the second glass substrate comprising opposite a third surface and a fourth surface of a pair, the third surface and the second surface being opposite to each other; a terahertz chip, the terahertz chip being fixed in the second glass substrate; a radiation electrode, the radiation electrode being located on one side of the third surface and corresponding to the waveguide opening, the radiation electrode being bonded to a portion of the metal film around the waveguide opening; an interconnection line, the interconnection line being located on the fourth surface and electrically connected to the terahertz chip; a signal transmission line, the signal transmission line passing through the second glass substrate in a direction from the third surface to the fourth surface, and the signal transmission line being electrically connected to both the radiation electrode and the interconnection line.

[0092] As can be seen from the above content, the technical solution provided in the embodiment of the present application sets the antenna layer as an antenna layer with a horn antenna groove structure. Due to the advantages of the horn antenna itself, the terahertz horn antenna has the advantages of simple structure, easy gain control, excellent frequency characteristics, low loss, etc. In addition, the antenna layer and the radio frequency layer provided in the embodiment of the present application are fixed by bonding the radiation electrode and the metal film, which not only realizes a low-reflection interconnection channel, but also can confine the THz wave to the bonding area, avoiding the problem of electromagnetic leakage caused by the stacking of the antenna layer and the radio frequency layer, and improving the performance of the terahertz horn antenna. In addition, the embodiment of the present application provides that the antenna layer and the radio frequency layer are both made of glass substrates. The glass substrate has the advantages of high mechanical strength and low dielectric loss, and the glass substrate can withstand higher temperatures, thereby reducing the problem of substrate warping and deformation, and thus can improve the preparation quality of the terahertz horn antenna.

[0093] In the description of the embodiments of the present application, it should be understood that the orientation or position relationship indicated by terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0094] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the embodiments of the present application, the meaning of "plurality" is at least two, for example, two, three, etc., unless otherwise clearly specified.

[0095] In the embodiments of this application, unless otherwise specified or limited, terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections, electrical connections, or communication between them; direct connections, indirect connections through an intermediate medium, and internal connections between two components or interactions between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0096] In the embodiments of the present application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," and "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0097] In the embodiments of the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0098] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A terahertz horn antenna, characterized in that: include: An antenna layer, the antenna layer comprising: a first glass substrate, the first glass substrate comprising a first surface and a second surface opposite to each other; at least one cavity, the cavity penetrating the first glass substrate from the first surface to the second surface, the cavity comprising a horn antenna groove located on one side of the first surface and a waveguide opening located on one side of the second surface; and a metal film, the metal film covering at least the first surface, the second surface, and an inner wall of the cavity; A radio frequency layer, the radio frequency layer comprising: a second glass substrate, the second glass substrate comprising a third surface and a fourth surface opposite to each other, the third surface being opposite to the second surface; a terahertz chip, the terahertz chip being fixed in the second glass substrate; a radiation electrode, the radiation electrode being located on one side of the third surface and corresponding to the waveguide opening, the radiation electrode being bonded to a portion of the metal film around the waveguide opening; an interconnection line, the interconnection line being located on the fourth surface and electrically connected to the terahertz chip; and a signal transmission line, the signal transmission line penetrating the second glass substrate in a direction from the third surface to the fourth surface, and the signal transmission line being electrically connected to both the radiation electrode and the interconnection line.

2. The terahertz horn antenna according to claim 1, characterized in that: The signal transmission line includes: at least one inner conductive via; and a plurality of outer conductive through-holes arranged around the at least one inner conductive through-hole, wherein the inner conductive through-holes and the outer conductive through-holes both penetrate the second glass substrate in a direction from the third surface to the fourth surface; The inner conductive via and the plurality of outer conductive vias form a substrate-integrated coaxial line structure.

3. The terahertz horn antenna according to claim 2, characterized in that: The radiation electrode comprises: a matching electrode, the matching electrode being electrically connected to the inner conductive through hole and located within the range of the waveguide opening; and a ground electrode surrounding the matching electrode, wherein the ground electrode is electrically connected to the outer conductive via, and the ground electrode is bonded to a portion of the metal film around the waveguide opening.

4. The terahertz horn antenna according to claim 1, wherein: The signal transmission line includes: a first conductive via row and a second conductive via row disposed opposite to each other; The first conductive via in the first conductive via row and the second conductive via in the second conductive via row both penetrate the second glass substrate along a direction from the third surface to the fourth surface; The first conductive via row and the second conductive via row form a substrate integrated waveguide structure.

5. The terahertz horn antenna according to claim 4, characterized in that: The radiation electrode includes a coupling slot, and the coupling slot is located within the range of the waveguide opening.

6. The terahertz horn antenna according to claim 1, characterized in that: The waveguide opening is a rectangular waveguide opening.

7. The terahertz horn antenna according to claim 1, wherein: The radio frequency layer includes a heat dissipation opening on one side of the fourth surface, and the heat dissipation opening exposes at least a portion of the surface of the terahertz chip.

8. A method for preparing a terahertz horn antenna, characterized in that: For preparing the terahertz horn antenna according to any one of claims 1 to 7, the preparation method comprises: preparing an antenna layer and a radio frequency layer; Aligning and fixing the antenna layer and the radio frequency layer; The antenna layer includes: a first glass substrate, the first glass substrate including a first surface and a second surface facing each other; at least one cavity, the cavity penetrating the first glass substrate from the first surface to the second surface, the cavity including a horn antenna groove located on one side of the first surface and a waveguide opening located on one side of the second surface; and a metal film, the metal film covering at least the first surface, the second surface, and the inner wall of the cavity; The radio frequency layer includes: a second glass substrate, the second glass substrate includes a third surface and a fourth surface opposite to each other, the third surface and the second surface being opposite to each other; a terahertz chip, the terahertz chip being fixed in the second glass substrate; a radiation electrode, the radiation electrode being located on one side of the third surface and corresponding to the waveguide opening, the radiation electrode being bonded to a portion of the metal film around the waveguide opening; an interconnection line, the interconnection line being located on the fourth surface and electrically connected to the terahertz chip; and a signal transmission line, the signal transmission line passing through the second glass substrate in a direction from the third surface to the fourth surface, and the signal transmission line being electrically connected to both the radiation electrode and the interconnection line.

9. The method for preparing a terahertz horn antenna according to claim 8, wherein: The method for preparing the antenna layer includes: Etching the first glass substrate to form at least one cavity, the cavity penetrating the first glass substrate from the first surface to the second surface, the cavity comprising a horn antenna groove located on one side of the first surface and a waveguide opening located on one side of the second surface; The metal film is formed, and the metal film at least covers the first surface, the second surface and the inner wall of the cavity.

10. The method for preparing a terahertz horn antenna according to claim 8, wherein: The method for preparing the radio frequency layer includes: On one side of the fourth surface, etching the second glass substrate to form a plurality of blind holes and chip grooves; Filling the blind hole with conductive metal to form the signal transmission line, and forming a grounding metal layer on the inner wall of the chip groove; Fixing the terahertz chip in the chip groove; bonding a temporary substrate to one side of the fourth surface; On one side of the third surface, the second glass substrate is thinned to expose the signal transmission line; forming the radiation electrode on the third surface, wherein the radiation electrode is electrically connected to the signal transmission line; The temporary substrate is removed, and the interconnection circuit is formed on the fourth surface, wherein the interconnection circuit is electrically connected to both the terahertz chip and the signal transmission line.

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