Terahertz horn antenna and preparation method thereof

Abstract

The invention provides a terahertz horn antenna and a preparation method thereof, and relates to the technical field of mobile communication systems. The antenna layer is arranged to be the antenna layer with the horn antenna groove structure, and due to the advantages of the horn antenna, the terahertz horn antenna has the advantages of being simple in structure, convenient to control gain, excellent in frequency characteristic, small in loss and the like. Moreover, the antenna layer and the radio frequency layer provided by the invention are fixed through bonding of the radiation electrode and the metal film, so that a low-reflection interconnection channel is realized, THz waves can be limited in a bonding area, the problem of electromagnetic leakage caused by stacking of the antenna layer and the radio frequency layer is avoided, and the performance of the terahertz horn antenna is improved. According to the terahertz horn antenna, the antenna layer and the radio frequency layer both adopt the glass substrates, the glass substrates have the advantages of high mechanical strength, small dielectric loss and the like, and the glass substrates can bear higher temperature, so that the problems of warping and deformation of the substrates are reduced, and the preparation quality of the terahertz horn antenna can be improved.

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 a frequency range of 0.1~10 THz. They are the transition zone from macroscopic classical theory to microscopic quantum theory and are called the "THz gap" of the electromagnetic spectrum. THz technology can be widely used in radar, remote sensing, homeland security and counter-terrorism, highly confidential data communication and transmission, atmospheric and environmental monitoring, real-time bioinformation extraction, and medical diagnosis. Therefore, THz research has great application value to the national economy and national security, and THz antennas are one of the main research projects of today's researchers. 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, low loss, etc., while also avoiding the problem of electromagnetic leakage and improving 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] The antenna layer comprises: a first glass substrate, the first glass substrate comprises a first surface and a second surface opposite to each other; at least one cavity, the cavity penetrates the first glass substrate from the first surface to the second surface, the cavity comprises 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 at least covers the first surface, the second surface and the 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 being 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 the matching electrode being 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 comprises:

[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 includes a first surface and a second surface opposite to each other; at least one cavity, the cavity penetrates the first glass substrate in a direction from the first surface to the second surface, the cavity includes 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 at least covers 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 are opposite to each other; a terahertz chip, the terahertz chip is fixed in the second glass substrate; a radiation electrode, the radiation electrode is located on one side of the third surface and corresponds to the waveguide opening, the radiation electrode is bonded to a portion of the metal film around the waveguide opening; an interconnection line, the interconnection line is located on the fourth surface, and the interconnection line is electrically connected to the terahertz chip; a signal transmission line, the signal transmission line passes through the second glass substrate in a direction from the third surface to the fourth surface, and the signal transmission line is 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, thinning the second glass substrate to expose the signal transmission line;

[0036] The radiation electrode is formed on the third surface, and the radiation electrode is electrically connected to the signal transmission line;

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

[0038] Compared with the prior art, 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, wherein the terahertz horn antenna comprises: an antenna layer, wherein the antenna layer comprises: a first glass substrate, wherein the first glass substrate comprises a first surface and a second surface opposite to each other; at least one cavity, wherein the cavity penetrates the first glass substrate in a direction from the first surface to the second surface, wherein the cavity comprises 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, wherein the metal film at least covers the first surface, the second surface and the inner wall of the cavity; a radio frequency layer, wherein the radio frequency layer comprises: a second glass substrate, wherein the second glass substrate comprises a first surface and a second surface opposite to each other; wherein the first surface and the second surface are opposite to each other; wherein the second ... a third surface and a fourth surface, 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 being electrically connected to the terahertz chip; 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.

[0040] It can be seen from the above content that 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 gain control, excellent frequency characteristics, and low loss. 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 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. In addition, the present application provides that both the antenna layer and the radio frequency layer use 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 problems 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 drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

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

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

[0044] Figure 3 A schematic diagram of the structure 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 diagram of the structure 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 Structural schematic diagrams of three coplanar waveguide transition structures provided in embodiments of the present application;

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

[0051] Figure 10a to Figure 10b A schematic diagram of the corresponding structures of the steps for preparing 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 the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0054] As mentioned in the background technology, terahertz (THz) waves refer to electromagnetic waves with a frequency range of 0.1~10 THz. They are the transition zone from macroscopic classical theory to microscopic quantum theory and are called the "THz gap" of the electromagnetic spectrum. THz technology can be widely used in radar, remote sensing, homeland security and counter-terrorism, highly confidential data communication and transmission, atmospheric and environmental monitoring, real-time bioinformation extraction, and medical diagnosis. Therefore, THz research has great application value to the national economy and national security, and terahertz antennas are one of the main research projects of today's researchers.

[0055] Specifically, 6G is a more advanced next-generation mobile communication system, and the transmission rate and bandwidth of 6G will be greatly improved by 10-100 times compared with 5G. Therefore, the 6G communication system must use the terahertz frequency band to achieve ultra-high transmission rate and ultra-large bandwidth, which puts forward high requirements on the integrated structure, such as: low-loss AiP (antenna package) antenna, low-reflection matching interconnection channel, low-loss material system and high-precision preparation process. The existing research on terahertz antennas mainly has the following problems: First, traditional antenna structures such as microstrip patch antennas and slot antennas have narrow bandwidth, low power capacity and high loss in the terahertz frequency band, and the substrate material has a great influence on the antenna performance. Second, transmitting the signal of the RF chip to the horn antenna is another problem. Conventional 3D integration solutions all use vertical interconnect structures represented by ball grid arrays (BGA), which have very serious high-frequency electromagnetic leakage and cause great reflection. 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 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 also avoids the problem of electromagnetic leakage and improves the performance of the terahertz horn antenna.

[0057] To achieve the above purpose, the technical solution provided in the embodiment of the present application is as follows, specifically combined with Figures 1 to 11gThe technical solution provided in the embodiments of the present application is 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 comprises: a first glass substrate 110, wherein the first glass substrate 110 comprises a first surface and a second surface opposite to each other; at least one cavity, wherein the cavity penetrates the first glass substrate 110 from the first surface to the second surface, wherein the cavity comprises 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 at least covers the first surface, the second surface and the inner wall of the cavity.

[0060] A radio frequency layer, the radio frequency layer comprising: a second glass substrate 210, the second glass substrate 210 comprising a third surface and a fourth surface opposite to each other, the third surface being opposite to the second surface; 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 the interconnection line 240 being electrically connected to the terahertz chip 220; 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 can be understood that in the terahertz chip provided in the embodiment of the present application, the antenna layer is set as an antenna layer with a horn antenna groove 121 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 230 and the metal film 130, and a planar bonding process is adopted to remove the existing interconnection structure such as BGA, which not only realizes a low-reflection interconnection channel, but also can limit 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. In addition, the embodiment of the present application provides that both the antenna layer and the radio frequency layer use a glass substrate. The glass substrate has the advantages of high mechanical strength, low dielectric loss, and easier flattening. The glass substrate can not only withstand higher temperatures, but also makes 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 actual situations, since it is impossible to etch a smooth ideal smooth inner wall on the 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 the ideal smooth inclined inner wall. The horn antenna (that is, the horn antenna groove) is formed by gradually opening the waveguide, which has the advantages of good frequency characteristics, low loss, low input standing wave ratio, and wide frequency band. The horn antenna groove 121 provided in the embodiment of the present application can be gradually expanded by a rectangular waveguide or a circular waveguide. Under the condition of the same main mode range, the volume of the rectangular waveguide is smaller, and the volume of the horn antenna groove 121 formed by the expansion is also more compact, especially in the high frequency band, it is easier to meet the requirements of the λ / 2 spacing of the phased antenna array. Therefore, in the construction of the horn antenna array in the terahertz frequency band, the horn antenna expanded by the rectangular waveguide is selected as the 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 arranged in the chip groove. Figure 1As shown, the terahertz chip 220 provided in the embodiment of the present application may 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, and the back electrode of the terahertz chip 220 may be electrically connected to the grounding metal layer 260 through a conductive structure 221; wherein the conductive structure 221 may be a conductive material such as a conductive glue or solder, and this application does not make any specific restrictions on this. Or refer to Figure 2 As shown, it is a schematic diagram of the structure 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 of the side wall through an external electrode 222.

[0064] Furthermore, the terahertz horn antenna provided in the embodiment of the present application also includes a ball implantation structure 270 electrically connected to the interconnection line 240, so as to facilitate the external connection of the terahertz horn antenna. Also, the radio frequency layer provided in the embodiment of the present application includes a heat dissipation opening 280 on one side of the fourth surface, and the heat dissipation opening 280 exposes at least part of the surface of the terahertz chip 220, thereby improving the heat dissipation effect of the terahertz chip 220, reducing the probability of damage to the terahertz chip 220, and ensuring a long service life of the terahertz horn antenna.

[0065] It should be noted that the terahertz chip 220 provided in the embodiment of the present application is fixedly arranged in the chip groove. In order to avoid the short circuit problem of the non-connected part 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. And, when the interconnection line 240 provided in the embodiment of the present application includes a single-layer line, it can be directly formed on the fourth surface of the second glass substrate 210 and protected by covering with an insulating material. Alternatively, when the interconnection line 240 includes a multi-layer line, adjacent line layers can be isolated by an insulating material to avoid the problem of short circuit connection between the lines. Similarly, the radiation electrode 230 provided in the embodiment of the present application can be directly formed on the third surface of the second glass substrate 210 and electrically connected to the signal transmission line 250; or, an insulating material layer can also be formed on the third surface of the second glass substrate 210 provided in the embodiment of the present application, and the radiation electrode 230 can be formed on the insulating material layer, and this application does not make specific restrictions.

[0066] The metal film 130 provided in the embodiment of the present application may be a metal film made of gold, and the present application does not make any specific restrictions on this. In order to improve the bonding strength between the metal film 130 made of gold and the first glass substrate 110, a titanium layer may be provided between the metal film 130 made of gold and the first glass substrate 110. Also, at least one of the radiation electrode 230, the interconnection line 240 and the signal transmission line 250 may also be made of gold. When the line segments of the radiation electrode 230, the interconnection line 240 and the signal transmission line 250 are in direct contact with the second glass substrate 210, a titanium layer may be provided between the line segments made of gold and the second glass substrate 210 to improve the bonding strength between the line segments made of gold and the second glass substrate 210.

[0067] In an 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 line structure. Figures 3 to 5 As shown, Figure 3 A schematic diagram of the structure of another terahertz horn antenna provided in an embodiment of the present application is shown in FIG. Figure 4 A top view of a radiation electrode provided in an embodiment of the present application, Figure 5 A top view of another radiation electrode provided in an embodiment of the present application. The signal transmission line 250 provided in an embodiment of the present application includes: at least one inner conductive through hole 251; and a plurality of outer conductive through holes 252 arranged around the at least one inner conductive through hole 251, wherein both the inner conductive through hole 251 and the outer conductive through holes 252 penetrate the second glass substrate 210 along the direction from the third surface to the fourth surface; the inner conductive through hole 251 and the plurality of outer conductive through holes 252 form a substrate-integrated coaxial line structure.

[0068] It can be understood that the coaxial line is a dual-conductor transmission line composed 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 signals. 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. Figure 4 As shown, the signal transmission line 250 provided in the embodiment of the present application may include an inner conductive via 251 and a plurality of outer conductive vias 252 arranged around the inner conductive via 251, the diameter of the inner conductive via 251 is larger than the diameter of the outer conductive via 252, and the inner conductive via 251 and the outer conductive via 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 via 252 provided in the embodiment of the present application is arranged in multiple circles around the inner conductive via 251; in addition, considering the process consistency, the diameter of the inner conductive via 251 provided in the embodiment of the present application is prepared to be consistent with the diameter of the outer conductive via 252, and the number of the inner conductive vias 251 is prepared as a plurality of conductive vias arranged along the annular direction, and the present application does not make any specific restrictions on this.

[0070] Continue to refer Figure 4 and Figure 5 As shown, in order to reduce the reflection of the transmission structure, the signal is transmitted from the conductive through hole of the substrate integrated coaxial line structure to the horn antenna. A coaxial-waveguide opening converter is required to reduce its insertion loss, thereby optimizing the design of the radiation electrode 230, wherein the radiation electrode 230 provided in the embodiment of the present application includes: a matching electrode 231, the matching electrode 231 is electrically connected to the inner conductive through hole 251, and the matching electrode 231 is located within the range of the waveguide opening 122; and a grounding electrode 232 surrounding the matching electrode 231, the grounding electrode 232 is electrically connected to the outer conductive through hole 252, and the grounding electrode 232 is bonded to the metal film 130 around the waveguide opening 122. The signal provided in 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 may also be a transmission line of a similar integrated waveguide structure. Figure 6 and Figure 7 As shown, Figure 6 A schematic diagram of the structure of another terahertz horn antenna provided in an embodiment of the present application is shown in FIG. Figure 7A 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. And, 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 an 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 will be given.

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

[0074] S1. Prepare antenna layer and 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 includes a first surface and a second surface opposite to each other; at least one cavity, the cavity penetrates the first glass substrate in a direction from the first surface to the second surface, the cavity includes 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 at least covers 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 are opposite to each other; a terahertz chip, the terahertz chip is fixed in the second glass substrate; a radiation electrode, the radiation electrode is located on one side of the third surface and corresponds to the waveguide opening, the radiation electrode is bonded to a portion of the metal film around the waveguide opening; an interconnection line, the interconnection line is located on the fourth surface, and the interconnection line is electrically connected to the terahertz chip; a signal transmission line, the signal transmission line passes through the second glass substrate in a direction from the third surface to the fourth surface, and the signal transmission line is electrically connected to both the radiation electrode and the interconnection line.

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

[0079] like Fig.10a As shown, the first glass substrate 110 is etched to form at least one cavity, which penetrates the first glass substrate 110 along the direction from the first surface to the second surface, and 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 by a laser induced etching process, thereby etching the horn antenna groove 121 and the waveguide opening 122 on the first glass substrate 110. Since it is impossible to etch an 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 Fig.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] Combination 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 Fig.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 Fig.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 Fig.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 III-V group 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 Fig.11d As shown, a temporary substrate 300 is bonded to one side of the fourth surface.

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

[0088] like Fig.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, and 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 radio frequency layer are prepared, a low-temperature metal layer planar bonding process is used to achieve bonding between the antenna layer and the radio frequency layer, so as to bond the radiation electrode 230 to the metal film 130 around the waveguide opening 122; finally, a ball planting structure 270 is manufactured on the side of the interconnection line 240 away from the radio frequency 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, wherein the terahertz horn antenna comprises: an antenna layer, wherein the antenna layer comprises: a first glass substrate, wherein the first glass substrate comprises a first surface and a second surface opposite to each other; at least one cavity, wherein the cavity penetrates the first glass substrate in a direction from the first surface to the second surface, wherein the cavity comprises 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, wherein the metal film at least covers the first surface, the second surface and the inner wall of the cavity; a radio frequency layer, wherein the radio frequency layer comprises: a second glass substrate, wherein the second glass substrate comprises a first surface and a second surface opposite to each other; wherein the first surface and the second surface are provided at least to the first surface and the second surface; wherein the second surface and the second surface are provided to ... a third surface and a fourth surface of a pair, the third surface and the second surface are opposite to each other; a terahertz chip, the terahertz chip is fixed in the second glass substrate; a radiation electrode, the radiation electrode is located on one side of the third surface and corresponds to the waveguide opening, the radiation electrode is bonded to a portion of the metal film around the waveguide opening; an interconnection line, the interconnection line is located on the fourth surface, and the interconnection line is electrically connected to the terahertz chip; a signal transmission line, the signal transmission line passes through the second glass substrate in a direction from the third surface to the fourth surface, and the signal transmission line is electrically connected to both the radiation electrode and the interconnection line.

[0092] It can be seen from the above content that 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, 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 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. In addition, the embodiment of the present application provides that both the antenna layer and the radio frequency layer use 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 problems 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 needs to 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", "circumferential", etc. 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 referred device or element 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 technical features indicated. Therefore, the features defined as "first" and "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, such as two, three, etc., unless otherwise clearly and specifically defined.

[0095] In the embodiments of the present application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0096] In the embodiments of the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "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" or "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, if the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" appear, it means 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 representations 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 the different embodiments or examples described in this specification and the features of the 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: The antenna layer comprises: a first glass substrate, the first glass substrate comprises a first surface and a second surface opposite to each other; at least one cavity, the cavity penetrates the first glass substrate from the first surface to the second surface, the cavity comprises 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 at least covers 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 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 being 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 comprises: 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 the matching electrode being 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, characterized in that: The signal transmission line comprises: 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, characterized in that: 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 includes a first surface and a second surface opposite to each other; at least one cavity, the cavity penetrates the first glass substrate in a direction from the first surface to the second surface, the cavity includes 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 at least covers 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 are opposite to each other; a terahertz chip, the terahertz chip is fixed in the second glass substrate; a radiation electrode, the radiation electrode is located on one side of the third surface and corresponds to the waveguide opening, the radiation electrode is bonded to a portion of the metal film around the waveguide opening; an interconnection line, the interconnection line is located on the fourth surface, and the interconnection line is electrically connected to the terahertz chip; a signal transmission line, the signal transmission line passes through the second glass substrate in a direction from the third surface to the fourth surface, and the signal transmission line is electrically connected to both the radiation electrode and the interconnection line.

9. The method for preparing a terahertz horn antenna according to claim 8, characterized in that: The method for preparing the antenna layer comprises: 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, characterized in that: The method for preparing the radio frequency layer comprises: 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, thinning the second glass substrate to expose the signal transmission line; The radiation electrode is formed on the third surface, and the radiation electrode is electrically connected to the signal transmission line; The temporary substrate is removed, and the interconnection line is formed on the fourth surface, wherein the interconnection line is electrically connected to both the terahertz chip and the signal transmission line.

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