Terahertz resonance tunneling diode radiation source of integrated cavity-backed patch antenna

Abstract

The invention discloses a terahertz resonant tunneling diode radiation source integrated with a cavity-backed patch antenna, which belongs to the technical field of terahertz wireless transceiving and comprises a substrate, and an RTD, the cavity-backed patch antenna, a GSG direct-current bias line and two stable resistors which are positioned above the substrate, the back cavity patch antenna comprises a back cavity bottom reference ground, a back cavity metal side wall, a back cavity passivation layer, a patch feeder line, a radiation patch and a back cavity top reference ground; the RTD and the GSG direct current bias line are located above the back cavity patch antenna, the radiation patch is connected to the radio frequency side of the RTD through the patch feeder line, and the GSG direct current bias line is connected to the direct current side of the RTD. Terahertz oscillation signals are excited through resonance of the RTD and the cavity-backed patch antenna, after the terahertz oscillation signals are enhanced through integrated cavity-backed resonance, high-gain radiation on the air side is achieved through the radiation patch, and loss of terahertz waves on the substrate side can be effectively reduced; compared with a traditional mode of loading a Si lens on the substrate side, the integrated back cavity structure has the advantages of miniaturization and low profile, and can meet application requirements.

Description

Technical Field

[0001] The invention belongs to the technical field of terahertz wireless transceiver, and in particular relates to a terahertz resonant tunneling diode radiation source with an integrated cavity-backed patch antenna. Background Art

[0002] Terahertz waves are located between microwaves and infrared, and have the characteristics of narrow beam, large bandwidth, strong penetration and low energy, which are very suitable for realizing monolithic integration of wireless communication and wireless sensing functions. By organically combining the sensing and communication functions, terahertz technology is mutually promoted and enhanced, further promoting the realization of "intelligent connection of all things". As a cutting-edge technology, terahertz technology has far-reaching significance for basic scientific research, national economic development and national defense construction, especially playing an indispensable and important role in the future 6G communication field. Terahertz wave source is the cornerstone of terahertz technology research and the core component of terahertz application system. The research and development of high-power, high-efficiency terahertz radiation sources that can operate at room temperature and have adjustable bandwidth has always been the focus of scientists and a hot area of ​​research.

[0003] In recent years, terahertz radiation sources based on resonant tunneling diodes (RTDs) as nonlinear devices have attracted widespread attention from researchers due to their small size, light weight, easy integration, room temperature operation and low power consumption, opening up new technical avenues for the application of terahertz technology.

[0004] At present, the RTD-based oscillators (RTD Oscillator, RTO) reported at home and abroad are mainly based on the InP material system, and the integrated antenna forms used mainly include slot antennas (such as Chinese patent No. 202110707842.0: A resonant tunneling diode terahertz oscillator and its circuit structure, Chinese patent No. 202410614915.5: A resonant tunneling diode oscillator and terahertz radiation source device, and Chinese patent No. 201610877332.7: Detuned fed slot antenna RTO terahertz wave source and manufacturing process), bow tie antennas (such as Chinese patent No. 20210707698.0: A resonant tunneling diode terahertz oscillator source, and the journal article "Design and realization of InP-based resonanttunneling diode THz oscillator”), and patch antennas (such as the Chinese patent No. 202310087308.3: resonant tunneling diode, oscillator and detection system).

[0005] Although the above-mentioned antenna can be integrated with the RTD monolithic chip to realize on-chip RTO, the following problems still exist: (1) The antenna gain is low, and it is not easy to achieve high radiation power, which is not conducive to the application of RTO in actual 6G communication systems; (2) The antenna radiation direction is likely to be toward the substrate side, which will increase the loss of terahertz waves in the substrate and is not conducive to achieving high DC-RF conversion efficiency; (3) Generally, the radiation gain is enhanced by loading Si lens on the substrate side, but the size of Si lens is generally much larger than the size of RTO itself, and most of them are semi-ellipsoidal lenses or hemispherical lenses, which occupy a large lateral and longitudinal area, which is not conducive to achieving low profile and miniaturization. Summary of the invention

[0006] In view of the problems existing in the existing integrated antenna forms, the present invention provides a terahertz resonant tunneling diode radiation source with an integrated back-cavity patch antenna. By integrating the back-cavity structure of the patch antenna, the resonance enhancement of the terahertz oscillation signal is achieved, and high-gain radiation is achieved facing the air side. It has the characteristics of high-gain radiation, low substrate loss, low profile and miniaturization.

[0007] The technical solution adopted by the present invention is as follows:

[0008] A terahertz resonant tunneling diode radiation source with an integrated cavity-backed patch antenna comprises a substrate, a resonant tunneling diode (RTD) located above the substrate, a cavity-backed patch antenna, a GSG DC bias line and two stabilizing resistors;

[0009] The back cavity patch antenna comprises a back cavity bottom reference ground, a back cavity metal side wall, a back cavity passivation layer, a patch feed line, a radiation patch and a back cavity top reference ground;

[0010] Among them, the RTD and the reference ground at the bottom of the back cavity are located on the upper surface of the substrate; the back cavity passivation layer is located on the upper surface of the reference ground at the bottom of the back cavity; the metal side wall of the back cavity is located inside the back cavity passivation layer, presenting an open ring structure; the patch feed line, the radiation patch, the reference ground at the top of the back cavity and the GSG DC bias line are all located on the upper surface of the back cavity passivation layer; the radiation patch is connected to the patch feed line, the radiation patch is specifically located in the inner area of ​​the ring structure of the metal side wall of the back cavity, and the patch feed line is specifically located in the open side area of ​​the metal side wall of the back cavity; the patch feed line is connected to the RF side of the RTD, and the GSG DC bias line is connected to the RF side of the RTD. The line is connected to the DC side of the RTD; the reference ground at the top of the back cavity is set around the patch feed line, the radiation patch and the RTD, and a gap is left between the patch feed line and the radiation patch to form an ohmic contact with the RTD; the two ground lines (G lines) of the GSG DC bias line are connected to the reference ground at the top of the back cavity; the two stabilizing resistors are respectively located in the gap between the ground line and the signal line in the GSG DC bias line, and close to the connection end of the GSG DC bias line and the RTD; the bottom end of the metal side wall of the back cavity is connected to the reference ground at the bottom of the back cavity, and the top end is connected to the reference ground at the top of the back cavity.

[0011] Furthermore, the RTD includes, from bottom to top, an emitter, an emitter isolation layer, an emitter potential barrier, a potential well layer, a collector potential barrier, a collector isolation layer, a collector and a collector top metal layer.

[0012] Furthermore, the patch feed line is connected to the top metal layer of the collector.

[0013] Furthermore, a signal line (S line) of the GSG DC bias line is connected to the collector top metal layer.

[0014] Furthermore, the reference ground portion at the top of the back cavity is located on the upper surface of the extension layer of the emitter, and forms an ohmic contact with the extension layer of the emitter.

[0015] Furthermore, the material of the stabilizing resistor is nickel-chromium alloy (Ni-Cr) or tantalum nitride (Ta-N).

[0016] Furthermore, an RTD passivation layer is provided between the collector and the collector top metal layer, and the RTD passivation layer extends around the RTD to protect and isolate the RTD, and a through hole is provided inside the RTD passivation layer to achieve connection between the collector and the collector top metal layer.

[0017] Furthermore, the material of the RTD passivation layer and the back cavity passivation layer is SiO2, SiN (Si3N4), SiON or BCB (benzocyclobuten).

[0018] Furthermore, the RTD is an InP-based RTD or a GaN-based RTD.

[0019] Furthermore, when the RTD is an InP-based RTD, the substrate is InP and the RTD epitaxial is In x Ga 1-x As / AlAs material system, 0 <x<1。

[0020] Furthermore, when the RTD is a GaN-based RTD, the substrate is GaN, and the RTD epitaxy is an AlGaN / GaN material system.

[0021] Furthermore, the radiation patch is a rectangular patch antenna or a bowtie patch antenna.

[0022] Furthermore, when the radiation patch is a bowtie patch antenna, a hollow dual antenna structure is specifically adopted, and at this time, the patch feed line is connected to the feed line end of the hollow dual antenna structure.

[0023] Furthermore, the back cavity metal side wall adopts a metal wall structure or a metal column structure.

[0024] The beneficial effects of the present invention are:

[0025] 1. The present invention proposes a terahertz resonant tunneling diode radiation source with an integrated cavity-backed patch antenna, which utilizes the resonance of RTD and cavity-backed patch antenna to excite a terahertz oscillation signal, and after being enhanced by the integrated cavity-backed resonance, high-gain radiation on the air side is achieved through the radiation patch;

[0026] 2. The present invention realizes resonance enhancement and air-side radiation by designing a cavity-backed patch antenna, thereby effectively reducing the loss of terahertz waves on the substrate side. Specifically: a cavity-backed patch antenna is integrated around the patch antenna to form a resonant microcavity, thereby enhancing the terahertz waves radiated by the patch antenna. At the same time, due to the presence of the cavity-backed patch antenna, the direction in which the terahertz waves are radiated by the patch antenna is directed toward the air side, thereby effectively reducing the substrate dielectric loss caused by the radiation of the terahertz waves toward the substrate side.

[0027] 3. Compared with the traditional method of loading Si lens on the substrate side to enhance radiation gain, the integrated back cavity structure of the present invention has the advantages of miniaturization and low profile, which can meet application requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The tape-out layout of the terahertz resonant tunneling diode radiation source with integrated cavity-backed patch antenna provided in Example 1 of the present invention;

[0029] Figure 2 A cross-sectional view of a terahertz resonant tunneling diode radiation source with an integrated cavity-backed patch antenna provided in Embodiment 1 of the present invention;

[0030] Figure 3 A 3D view of a terahertz resonant tunneling diode radiation source with an integrated cavity-backed patch antenna provided in Example 1 of the present invention;

[0031] Figure 4 Schematic diagram of the structure of RTD in Example 1 of the present invention;

[0032] Figure 5 An equivalent circuit diagram of a terahertz resonant tunneling diode radiation source with an integrated cavity-backed patch antenna provided in Example 1 of the present invention;

[0033] Figure 6 The resonance characteristic curve of the terahertz resonant tunneling diode radiation source of the integrated cavity-backed patch antenna provided in Example 1 of the present invention;

[0034] Figure 7 The radiation gain curve of the terahertz resonant tunneling diode radiation source of the integrated cavity-backed patch antenna provided in Example 1 of the present invention;

[0035] Figure 8The tape-out layout of the terahertz resonant tunneling diode radiation source with integrated cavity-backed patch antenna provided in Embodiment 2 of the present invention;

[0036] Fig. 9 Schematic diagram of the structure of RTD in Example 3 of the present invention;

[0037] The descriptions of the symbols in the accompanying drawings are as follows:

[0038] 1: substrate; 2: RTD; 3: reference ground at the bottom of the back cavity; 4: metal sidewall of the back cavity; 5: back cavity passivation layer; 6: patch feed line; 7: radiation patch; 8: reference ground at the top of the back cavity; 9: GSG DC bias line; 10: stabilizing resistor; 11: RTD nonlinear large / small signal model; 12: first circuit structure; 13: second circuit structure; 14: coplanar waveguide inductor L CPW ; 15: DC-RF bias-tee structure; 16: spectrum analyzer. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0040] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Example 1

[0042] This embodiment provides a terahertz resonant tunneling diode radiation source with an integrated cavity-backed patch antenna, the structure of which is as follows: Figure 1 , Figure 2 and Figure 3 As shown, it includes a substrate 1, and an RTD2, a cavity-backed patch antenna, a GSG DC bias line 9 and two stabilizing resistors 10 located above the substrate 1.

[0043] The back cavity patch antenna comprises a back cavity bottom reference ground 3, a back cavity metal side wall 4, a back cavity passivation layer 5, a patch feed line 6, a radiation patch 7 and a back cavity top reference ground 8.

[0044] The structure of RTD2 is as follows Figure 4As shown, it includes, from bottom to top, an emitter, an emitter isolation layer, an emitter potential barrier, a potential well layer, a collector potential barrier, a collector isolation layer, a collector and a collector top metal layer.

[0045] Among them, RTD2 and the back cavity bottom reference ground 3 are located on the upper surface of the substrate 1; the back cavity passivation layer 5 is located on the upper surface of the back cavity bottom reference ground 3; the back cavity metal side wall 4 is located inside the back cavity passivation layer 5, presenting an open square ring structure; the patch feed line 6, the radiation patch 7, the back cavity top reference ground 8 and the GSG DC bias line 9 are all located on the upper surface of the back cavity passivation layer 5; the radiation patch 7 is connected to the patch feed line 6; the radiation patch 7 is specifically a rectangular patch antenna, located in the inner area of ​​the square ring structure of the back cavity metal side wall 4; the patch feed line 6 is specifically located in the open side area of ​​the back cavity metal side wall 4; the patch feed line 6 is connected to the collector top metal layer of RTD2, and the signal line (S line) of the GSG DC bias line 9 is connected to The top metal layer of the collector of RTD2; the back cavity top reference ground 8 is set around the patch feed line 6, the radiation patch 7 and RTD2, and a gap is left between the patch feed line 6 and the radiation patch 7. The back cavity top reference ground 8 is partially located on the upper surface of the extension layer of the emitter of RTD2, and forms an ohmic contact with the extension layer of the emitter; the two ground wires (G lines) of the GSG DC bias line 9 are connected to the back cavity top reference ground 8; the two stabilizing resistors 10 are respectively located in the gap between the ground wire and the signal wire in the GSG DC bias line 9, and are close to the connection end of the GSG DC bias line 9 and RTD2; the bottom end of the back cavity metal side wall 4 is connected to the back cavity bottom reference ground 3, and the top end is connected to the back cavity top reference ground 8.

[0046] The materials used in each structure in this embodiment are as follows:

[0047] The material of the substrate 1 is semi-insulating (SI) InP material.

[0048] The RTD2 is an InP-based RTD, and the epitaxial wafer of RTD2 is prepared by a molecular beam epitaxy (MBE) process, including the preparation of an emitter, an emitter isolation layer, an emitter potential barrier, a potential well layer, a collector potential barrier, a collector isolation layer and a collector from bottom to top, and then the collector top metal layer is evaporated on the epitaxial wafer, and the collector top metal layer is used as a mask to expose the RTD2 structure by wet etching and photolithography, and the etching is stopped when the emitter is etched, and a resist is coated on the upper surface of the emitter, and wet etching is continued until the upper surface of the substrate 1 to obtain an extension layer of the emitter, and the resist is stripped by a wet stripping process, and the surface is cleaned to obtain RTD2; wherein, the emitter adopts a heavily doped layer (n++ / n+)In 0.53 Ga 0.47As; the emitter isolation layer uses unintentional doped (UID) In 0.53 Ga 0.47 As, thickness is 5nm; emitter barrier, potential well layer and collector barrier adopt UID's In 0.8 Ga 0.2 As / AlAs / In 0.8 Ga 0.2 As heterojunction, thickness 1.2 / 4.5 / 1.2nm; collector isolation layer uses UID's In 0.53 Ga 0.47 As, thickness 5nm; collector uses heavily doped layer (n+ / n++)In 0.53 Ga 0.47 As; the collector top metal layer adopts Ti / Pd / Au metal system; preferably, the emitter and collector surfaces are further heavily doped to obtain corresponding contact layers, and the doping concentration of the obtained emitter contact layer and collector contact layer is 3×10 19 cm -3 , the doping concentration of the emitter and collector is 3×10 18 cm -3 , the thickness of the emitter contact layer is 400nm, the thickness of the emitter is 25nm, the thickness of the collector is 25nm, and the thickness of the collector contact layer is 10nm.

[0049] The material of the back cavity passivation layer 5 is SiO2.

[0050] The material of the stabilizing resistor 10 is nickel-chromium alloy.

[0051] The materials of the back cavity bottom reference ground 3, the back cavity metal side wall 4, the patch feed line 6, the radiation patch 7, the back cavity top reference ground 8 and the GSG DC bias line 9 are Au; wherein the back cavity metal side wall 4 adopts a metal wall structure.

[0052] The process flow of the terahertz resonant tunneling diode radiation source with integrated cavity-backed patch antenna proposed in this embodiment is as follows:

[0053] Step 1, epitaxially preparing an emitter, an emitter isolation layer, an emitter potential barrier, a potential well layer, a collector potential barrier, a collector isolation layer and a collector in sequence on the surface of substrate 1 by molecular beam epitaxy to obtain an epitaxial wafer required for RTD2 etching;

[0054] Step 2: using an electron beam evaporation process to accurately locate the RTD2 region on the upper surface of the epitaxial wafer, and uniformly evaporate the collector top metal layer on the upper surface of the epitaxial wafer; using a wet etching process, using the collector top metal layer as a mask, etching the epitaxial material until the upper surface of the emitter material of RTD2;

[0055] Step 3, using a photolithography process to uniformly coat a photoresist on the exposed upper surface of the emitter material, obtaining an extended layer region of the emitter through exposure and development, and using a wet etching process to etch the emitter material outside the photoresist, thereby forming an emitter with an extended layer; further etching the substrate 1 until the depth of the back cavity bottom reference ground 3 required on the upper surface of the substrate 1 is reached, and using an electron beam evaporation process to sputter a metal layer on the upper surface of the etched substrate 1 to obtain the back cavity bottom reference ground 3;

[0056] Step 4, using a photolithography process, coating a photoresist on the upper surface of the reference ground 3 at the bottom of the back cavity, accurately aligning the mask of the metal wall structure with the surface of the photoresist coating, and then using an exposure process to project the mask pattern onto the photoresist surface to complete mask photolithography to form a photolithography groove, using an electron beam evaporation process to sputter the metal into the photolithography groove to form a metal side wall 4 of the back cavity, and finally using a wet removal process to strip the photoresist;

[0057] Step 5: using a plasma enhanced chemical vapor deposition process, a passivation layer is deposited on the reference ground 3 at the bottom of the back cavity and the surface of the metal sidewall 4 of the back cavity, and the deposition thickness reaches the bottom of the emitter of RTD2 to obtain a back cavity passivation layer 5;

[0058] Step 6: Using electron beam evaporation technology, a metal layer is uniformly sputtered on the upper surface of the back cavity passivation layer 5, and interconnected with the top metal layer of the collector of RTD2 to obtain a patch feeder 6;

[0059] Step 7: using an electron beam evaporation process, uniformly sputtering a metal layer on the upper surface of the back cavity passivation layer 5, and interconnecting it with the patch feeder 6 to obtain a radiation patch 7;

[0060] Step 8: Use electron beam evaporation technology to uniformly sputter a metal layer on the upper surface of the back cavity passivation layer 5, and form a semi-open annular metal layer surrounding the patch feed line 6 and the radiation patch 7. The metal layer at the open end is evaporated to the upper surface of the extension layer of the emitter of RTD2 to form an ohmic contact therewith, thereby obtaining a reference ground 8 at the top of the back cavity;

[0061] Step 9, using an electron beam evaporation process, uniformly sputtering a metal layer on the upper surface of the back cavity passivation layer 5 to obtain a GSG DC bias line 9, wherein the signal line is interconnected with the top metal layer of the collector of RTD2, and the ground line is interconnected with the reference ground 8 at the top of the back cavity;

[0062] Step 10: Use thin film sputtering or evaporation deposition technology to deposit thin film material at one end of the interconnection position between the GSG DC bias line 9 and RTD2. The deposition area is inside the groove formed by the signal line and the ground line of the GSG DC bias line 9 to obtain a stable resistor 10, thereby completing the preparation of the terahertz resonant tunneling diode radiation source with an integrated back cavity patch antenna.

[0063] The working principle of the terahertz resonant tunneling diode radiation source with an integrated back-cavity patch antenna proposed in this embodiment is: by applying a bias voltage to the GSG DC bias line 9, RTD2 is made to operate in the negative differential resistance region, and the negative differential resistance can compensate for the loss of the back-cavity patch antenna, thereby forming energy transfer between the back-cavity patch antenna and the loop of RTD2, generating an oscillation signal, and realizing radiation through the back-cavity patch antenna.

[0064] The equivalent circuit of the terahertz resonant tunneling diode radiation source with integrated cavity-backed patch antenna proposed in this embodiment is as follows: Figure 5 As shown, the RTD2 is represented as an RTD nonlinear large / small signal model 11; the patch feed line 6 and the radiation patch 7 are equivalent to a first circuit structure 12, including an equivalent capacitance C of the radiation patch 7 to the reference ground 8 at the top of the back cavity ant. , the equivalent inductance L of the radiation patch 7 ant. And the radiation conductance G of the radiation patch 7 to the air side ant. The back cavity bottom reference ground 3, the back cavity metal sidewall 4 and the back cavity passivation layer 5 are equivalent to a second circuit structure 13, including an equivalent capacitance C of the radiation patch 7 to the back cavity bottom reference ground 3 backcav. , the loss conductance G of the back cavity passivation layer 5 backcav. And the equivalent inductance L of the back cavity metal side wall 4 backcav. The GSG DC bias line 9 is equivalent to the coplanar waveguide inductor L CPW 14; DC-RF bias-tee structure 15 is used for feeding and RF testing, and the RF signal is analyzed by spectrum analyzer 16, where V bias represents the bias supply voltage, R bias Represents the bias supply resistance.

[0065] The input admittance Y of the cascade connection of the first circuit structure 12 and the second circuit structure 13 passive It is expressed as:

[0066]

[0067] The above formula can be simplified as:

[0068] Y passive =Y ant. +Y backcav. #(2)

[0069] Where Y ant. represents the input admittance of radiating patch 7, Y backcav. represents the input admittance of the back cavity, which includes:

[0070]

[0071] Among them, G ant.represents the real part of the input admittance of the radiation patch 7, B ant. represents the imaginary part of the input admittance of the radiation patch 7, G backcav. represents the real part of the back cavity input admittance, B backcav. represents the imaginary part of the back cavity input admittance.

[0072] and then, Figure 5 The input admittance Y shown in for:

[0073]

[0074] The RTO circuit oscillation conditions are:

[0075]

[0076] The RTO output power is:

[0077]

[0078] In the formula, G passive Represents Y passive The real part of , that is:

[0079] G passive =G ant. +G backcav. #(7)

[0080] In particular, the resonant tunneling diode radiation source of the integrated cavity-backed patch antenna provided in this embodiment can generate a greater output power than the radiation source of the integrated resonant tunneling diode of the ordinary patch antenna, because the output power of the radiation source of the integrated resonant tunneling diode of the ordinary patch antenna can be expressed as:

[0081]

[0082] Combining equations (6) and (8), we can see that:

[0083]

[0084] Furthermore, the output power of the resonant tunneling diode radiation source of the integrated back cavity patch antenna provided in this embodiment is greater than that of the radiation source of the integrated resonant tunneling diode of the ordinary patch antenna, which is mainly due to the real part of the input admittance G of the back cavity integrated in the former. backcav. The enhancement of the RTO output power indicates that high-gain radiation can be achieved through the integrated back-cavity resonance enhancement.

[0085] The resonance characteristic curve of the terahertz resonant tunneling diode radiation source with integrated cavity-backed patch antenna provided in this embodiment is as follows: Figure 6As shown in the figure, it can be seen that in the frequency band of 325~410GHz, the terahertz resonant tunneling diode radiation source of the integrated cavity-backed patch antenna oscillates at 365GHz. At this time, the imaginary part of the input admittance of the entire RTO circuit is 11}=0; the radiation gain curve is as follows Figure 7 As shown, the terahertz wave radiation direction of the terahertz resonant tunneling diode radiation source of the obtained integrated back-cavity patch antenna at 365 GHz is the air side, and the maximum radiation gain shown in the "★" position in the figure is 4.06 dBi, which can effectively reduce the substrate dielectric loss caused by the radiation of the terahertz wave to the substrate side.

[0086] This embodiment integrates a back cavity structure into the patch antenna to achieve resonance enhancement of the terahertz oscillation signal and realizes high-gain radiation facing the air side. It has the characteristics of high-gain radiation, low substrate loss, low profile and miniaturization.

[0087] Example 2

[0088] This embodiment provides a resonant tunneling diode radiation source with an integrated cavity-backed patch antenna, the structure of which is as follows: Figure 8 As shown, compared with Example 1, the structural difference is only that: the structure of the radiation patch 7 is adjusted to a bowtie patch antenna, specifically a hollow dual antenna structure is adopted, and at this time the patch feed line 6 is connected to the feed line end of the hollow dual antenna structure.

[0089] The process implementation method of the bowtie patch antenna is as follows: first, photoresist is coated on the upper surface of the back cavity passivation layer 5, and a bowtie patch antenna pattern is formed by exposure through a bowtie structure mask; then, an electron beam evaporation process is used to sputter a metal layer around the bowtie patch antenna photoresist pattern to form a back cavity top reference ground 8, and a semi-open annular metal layer is formed around the bowtie patch antenna photoresist pattern and the patch feed line 6, and the metal layer at the open end is evaporated to the upper surface of the collector of RTD2 to form an ohmic contact therewith, and after removing the photoresist, the bowtie patch antenna and the back cavity top reference ground 8 are obtained.

[0090] The other structures and working principles are the same as those in Example 1.

[0091] Example 3

[0092] This embodiment provides a resonant tunneling diode radiation source with an integrated cavity-backed patch antenna, which differs from the embodiment 1 only in that the material of the substrate 1 is adjusted to GaN, and RTD2 is made of Fig. 9 In the structure shown, the RTD epitaxy is an AlGaN / GaN material system; other structures and working principles are the same as those in Example 1.

[0093] Example 4

[0094] This embodiment provides a resonant tunneling diode radiation source with an integrated cavity-backed patch antenna, which differs from Embodiment 2 only in that the material of the substrate 1 is adjusted to GaN, and RTD2 is made of Fig. 9 In the structure shown, the RTD epitaxy is an AlGaN / GaN material system; other structures and working principles are the same as those in Example 2.

[0095] The above embodiments only illustrate the principles and advantages of the present invention, and are not intended to limit the present invention. They are only intended to help understand the principles of the present invention. The protection scope of the present invention is not limited to the above configurations and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the disclosed technology without departing from the essence of the present invention, but they are still within the protection scope of the present invention.

Claims

1. A terahertz resonant tunneling diode radiation source with integrated cavity-backed patch antenna, characterized in that: It includes a substrate, and an RTD, a cavity-backed patch antenna, a GSG DC bias line, and two stabilizing resistors located above the substrate; The back cavity patch antenna comprises a back cavity bottom reference ground, a back cavity metal side wall, a back cavity passivation layer, a patch feed line, a radiation patch and a back cavity top reference ground; Among them, the RTD and the reference ground at the bottom of the back cavity are located on the upper surface of the substrate; the back cavity passivation layer is located on the upper surface of the reference ground at the bottom of the back cavity; the metal side wall of the back cavity is located inside the back cavity passivation layer, presenting an open ring structure; the patch feed line, the radiation patch, the reference ground at the top of the back cavity and the GSG DC bias line are all located on the upper surface of the back cavity passivation layer; the radiation patch is connected to the patch feed line, the radiation patch is specifically located in the inner area of ​​the ring structure of the metal side wall of the back cavity, and the patch feed line is specifically located in the open side area of ​​the metal side wall of the back cavity; the patch feed line is connected to the RF side of the RTD, and the GSG DC bias line is connected to the RF side of the RTD. The GSG DC bias line is connected to the DC side of the RTD; the reference ground at the top of the back cavity is set around the patch feed line, the radiation patch and the RTD, and a gap is left between the patch feed line and the radiation patch to form an ohmic contact with the RTD; the two ground lines of the GSG DC bias line are connected to the reference ground at the top of the back cavity; the two stabilizing resistors are respectively located in the gap between the ground line and the signal line in the GSG DC bias line, and close to the connection end of the GSG DC bias line and the RTD; the bottom end of the metal side wall of the back cavity is connected to the reference ground at the bottom of the back cavity, and the top end is connected to the reference ground at the top of the back cavity.

2. According to claim 1, the terahertz resonant tunneling diode radiation source with integrated cavity-backed patch antenna is characterized in that: The RTD comprises, from bottom to top, an emitter, an emitter isolation layer, an emitter potential barrier, a potential well layer, a collector potential barrier, a collector isolation layer, a collector and a collector top metal layer.

3. The terahertz resonant tunneling diode radiation source with integrated cavity-backed patch antenna according to claim 2, characterized in that: The patch feed is connected to the collector top metal layer.

4. The terahertz resonant tunneling diode radiation source with integrated cavity-backed patch antenna according to claim 2, characterized in that: The signal line of the GSG DC bias line is connected to the collector top metal layer.

5. The terahertz resonant tunneling diode radiation source with integrated cavity-backed patch antenna according to claim 2, characterized in that: The reference ground portion at the top of the back cavity is located on the upper surface of the extension layer of the emitter and forms an ohmic contact with the extension layer of the emitter.

6. The terahertz resonant tunneling diode radiation source with integrated cavity-backed patch antenna according to any one of claims 1 to 5, characterized in that: An RTD passivation layer is provided between the collector and the collector top metal layer. The RTD passivation layer extends around the RTD to protect and isolate the RTD. A through hole is provided inside the RTD passivation layer to achieve connection between the collector and the collector top metal layer.

7. The terahertz resonant tunneling diode radiation source with integrated cavity-backed patch antenna according to claim 6, characterized in that: The material of the stabilizing resistor is nickel-chromium alloy or tantalum nitride, and the materials of the RTD passivation layer and the back cavity passivation layer are SiO2, Si3N4, SiON or BCB.

8. The terahertz resonant tunneling diode radiation source with integrated cavity-backed patch antenna according to any one of claims 1 to 5, characterized in that: The RTD is an InP-based RTD or a GaN-based RTD; when the RTD is an InP-based RTD, the substrate is InP, and the RTD epitaxy is In x Ga 1-x As / AlAs material system; when the RTD is a GaN-based RTD, the substrate is GaN, and the RTD epitaxy is an AlGaN / GaN material system.

9. The terahertz resonant tunneling diode radiation source with integrated cavity-backed patch antenna according to any one of claims 1 to 5, characterized in that: The radiating patch is a rectangular patch antenna or a bowtie patch antenna. When the radiating patch is a bowtie patch antenna, a hollow dual antenna structure is specifically adopted. At this time, the patch feed line is connected to the feed line end of the hollow dual antenna structure.

10. The terahertz resonant tunneling diode radiation source with integrated cavity-backed patch antenna according to any one of claims 1 to 5, characterized in that: The metal side wall of the back cavity adopts a metal wall structure or a metal column structure.

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