Optically induced integrated phase change radio frequency switch
By integrating a laser with a passive phase-change RF switch and using metasurface lenses for beam combining, the problem of the inability to integrate optically controlled phase-change RF switches has been solved, achieving faster switching speeds and higher isolation, reducing costs and size, and improving practicality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NAT UNIV OF DEFENSE TECH
- Filing Date
- 2023-04-27
- Publication Date
- 2026-07-14
AI Technical Summary
Existing light-controlled phase-change RF switches cannot be integrated into a single design, resulting in large size, high cost, and poor practicality.
The laser is integrated with a passive phase-change RF switch. The design uses a spaced laser array, a lens layer and a passive phase-change RF switch. A metasurface lens is used for beam combining. The laser emitted from the laser array passes through the lens layer and then enters the passive phase-change RF switch.
It achieves faster switching speeds (nanoscale), improves switch isolation, and features a simple structure, easy integration, small size, and low cost, meeting the switching requirements at the micrometer level.
Smart Images
Figure CN116390638B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of radio frequency switch technology, and in particular to a light-induced integrated phase-change radio frequency switch. Background Technology
[0002] Radio frequency (RF) switches, also known as microwave switches, are used to control the switching of radio frequency (RF) signal channels. They are indispensable key components in the RF front-end of radar, communication, and electronic warfare systems. As operating frequencies increase, the performance of traditional solid-state switches (PIN diodes and FETs) deteriorates sharply at high frequencies, and their costs increase exponentially. This has constrained the research and development of millimeter-wave and even terahertz devices. To address this issue, the emergence of new RF switch technologies is urgently needed.
[0003] Phase-change radio frequency (RF) switches, as a novel RF switching technology, hold promise for solving current problems in RF switches. Over the past few years, RF switches have proven to possess excellent characteristics, such as high isolation, low insertion loss, low parasitic capacitance, low power consumption, ultra-wide bandwidth, and ease of integration. Phase-change materials, as the core functional layer of RF switches, achieve reversible switching between high-resistance and low-resistance phase states through electrical excitation or optical induction, thereby enabling the switching on and off of the RF switch.
[0004] In existing technologies, optically induced excitation methods can effectively reduce structural complexity and improve switching speed compared to electrical excitation methods. For example, Aurelian Crunteanu et al. disclosed an optically controlled GeTe phase change RF switch that can achieve high isolation and low insertion loss in the 0-67 GHz range (Aurelian Crunteanu, Laure Huitema, Jean-Christophe Orlianges, et al. Optical Switching of GeTe Phase Change Materials for High-Frequency Applications[C]. IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes (IMWS-AMP), 2017).
[0005] However, although the above design achieves good high-frequency performance and fast switching, it uses an independent ultraviolet laser source and does not integrate the excitation source and switch, resulting in a large size and high cost, thus greatly reducing its practicality. Summary of the Invention
[0006] Based on this, it is necessary to provide a light-induced integrated phase-change RF switch to address the above-mentioned technical problems. This solves the problem of the inability to integrate light-controlled phase-change RF switches, and enables the integration of lasers with passive phase-change RF switches, reducing size and cost and greatly improving practicality.
[0007] A light-induced integrated phase-change radio frequency switch includes: multiple lasers, a lens layer, and a passive phase-change radio frequency switch;
[0008] Multiple lasers are spaced apart on the same plane to form a laser array;
[0009] The lens layer is spaced apart from the laser array and the passive phase-change radio frequency switch, so that the laser emitted from the laser array enters the passive phase-change radio frequency switch after passing through the lens layer.
[0010] In one embodiment, the lens layer includes: a collimating lens and a focusing lens;
[0011] The collimating lens is disposed between the laser array and the focusing lens, and the focusing lens is disposed between the collimating lens and the passive phase-change radio frequency switch.
[0012] In one embodiment, the area of the emitted light from the focusing lens is equal to the area of the phase change layer in the passive phase change radio frequency switch.
[0013] In one embodiment, both the collimating lens and the focusing lens are metasurface lenses.
[0014] In one embodiment, the laser array, the collimating lens, the focusing lens, and the passive phase-change radio frequency switch are parallel to each other.
[0015] In one embodiment, the passive phase-change radio frequency switch comprises, in sequence, a substrate layer, a heat dissipation layer, a phase-change layer, an electrode layer, and a passivation layer.
[0016] The passivation layer is adjacent to the lens layer at a distance.
[0017] In one embodiment, the substrate layer is disposed at the bottom of the heat dissipation layer and is the same size as the heat dissipation layer;
[0018] The phase change layer is disposed at the top center of the heat dissipation layer and has an area smaller than that of the heat dissipation layer;
[0019] The electrode layer includes a first part and a second part that are stacked together; the first part is sleeved on the outside of the phase change layer and its outer edge is parallel to the edge of the heat dissipation layer; the first part has the same thickness as the phase change layer so that the top of the first part and the top of the phase change layer are coplanar; the outer edge of the second part has the same size as the heat dissipation layer and forms an opening in the center of the top of the phase change layer.
[0020] The passivation layer fills the cavity and covers the top of the electrode layer.
[0021] In one embodiment, the laser is a bottom-emitting vertical-cavity surface-emitting laser.
[0022] In one embodiment, the laser comprises, in sequence: an N-type contact layer, an antireflection film, an N-type substrate, an N-type DBR, a quantum well active region, an oxide window, a P-type DBR, and a P-type contact layer;
[0023] The N-type contact layer and the antireflective film are both adjacent to the lens layer at intervals.
[0024] In one embodiment, the laser is grown using MOCVD.
[0025] The aforementioned optically induced integrated phase-change RF switch comprises a spaced laser array, a lens layer, and a passive phase-change RF switch. The emitted laser from the laser array passes through the lens layer and then enters the passive phase-change RF switch. Compared to existing electrically excited phase-change RF switches, the optically excited phase-change RF switch in this application offers a faster switching speed, reaching the nanosecond level. Furthermore, by reducing the complexity of the heater design, the isolation of the switch is further improved. Simultaneously, this application arranges multiple VCSEL lasers into a two-dimensional array to increase laser power and uses a collimating lens to collimate the multiple beams before using… The focusing lens converges the collimated beam onto a spot of appropriate size, which can completely cover the phase change layer. In other words, the area of the emitted light from the focusing lens is equal to the area of the phase change layer in the passive phase change RF switch, ensuring the high efficiency of laser energy and providing sufficient phase change energy to the phase change layer to ensure the normal phase change function of the phase change switch. In addition, this application integrates the bottom-emitting laser (i.e., the optical excitation source), the metasurface lens, and the passive phase change RF switch into a single design, which can meet the switching requirements at the micrometer level and has the advantages of simple structure, easy integration, small size, low cost, and high practicality. Attached Figure Description
[0026] Figure 1 This is a schematic diagram of a light-induced integrated phase-change radio frequency switch in one embodiment;
[0027] Figure 2 This is a schematic diagram of a laser in one embodiment, where the arrow indicates the direction of the light output port;
[0028] Figure 3 This is a schematic diagram of a passive phase-change radio frequency switch in one embodiment.
[0029] Figure label:
[0030] 1. Passive phase-change radio frequency switch; 2. Focusing lens; 3. Collimating lens; 4. Laser; 5. Laser beam path.
[0031] 6. N-type contact layer; 7. Antireflection film; 8. N-type substrate; 9. N-type DBR; 10. Quantum well active region; 11. Oxide window; 12. P-type DBR; 13. P-type contact layer.
[0032] Substrate layer 14, heat dissipation layer 15, phase change layer 16, electrode layer 17, passivation layer 18. Detailed Implementation
[0033] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.
[0034] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.
[0035] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. In the description of this application, "multiple sets" means at least two sets, such as two sets, three sets, etc., unless otherwise explicitly specified.
[0036] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0037] Furthermore, the technical solutions of the various embodiments of this application can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this application.
[0038] This application provides a light-induced integrated phase-change radio frequency switch, such as... Figures 1 to 3 As shown, in one embodiment, it includes: a plurality of lasers 4, a lens layer, and a passive phase-change radio frequency switch 1.
[0039] Multiple lasers 4 are distributed at intervals on the same plane to form a two-dimensional laser array. The specific array form and the number of lasers are not limited, for example, a square array.
[0040] The lens layer includes a collimating lens 3 and a focusing lens 2. Both the collimating lens and the focusing lens are metasurface lenses, meaning that the collimating lens is a metasurface collimating lens and the focusing lens is a metasurface focusing lens. This allows for integration with a passive phase-change radio frequency switch, overcoming the high integration difficulty of traditional lenses and achieving laser beamforming. As a two-dimensional planar structure, it has advantages over traditional lenses, such as lighter weight, smaller size, lower cost, and easier integration, making it easier to design and install. There are no restrictions on the specific metasurface form or the number of lenses. The collimating lens is spaced between the laser array and the focusing lens, and the focusing lens is spaced between the collimating lens and the passive phase-change radio frequency switch.
[0041] The passive phase-change radio frequency switch 1 includes, in sequence, a substrate layer 14, a heat dissipation layer 15, a phase change layer 16, an electrode layer 17, and a passivation layer 18; the passivation layer and the lens layer are adjacent to each other. Specifically: the substrate layer 14 is disposed at the bottom of the heat dissipation layer 15 and is the same size as the heat dissipation layer; the phase change layer 16 is disposed at the top center of the heat dissipation layer and has an area smaller than the heat dissipation layer; the electrode layer 17 includes a first part and a second part that are stacked together, the first part is sleeved on the outside of the phase change layer and the outer edge is parallel to the edge of the heat dissipation layer, the first part has the same thickness as the phase change layer so that the top of the first part and the top of the phase change layer are coplanar, the outer edge of the second part is the same size as the heat dissipation layer, and an opening cavity is formed at the top center of the phase change layer; the passivation layer 18 fills the cavity and covers the top of the electrode layer.
[0042] In this embodiment, the laser is a bottom-emitting vertical cavity surface-emitting laser (i.e., a bottom-emitting VCSEL laser), which includes the following layers stacked in sequence: an N-type contact layer 6, an anti-reflection film 7, an N-type substrate 8, an N-type DBR 9, a quantum well active region 10, an oxide window 11, a P-type DBR 12, and a P-type contact layer 13; the N-type contact layer and the anti-reflection film are adjacent to the lens layer at intervals. Specifically: The N-type contact layer 6 is located at the bottom of the N-type substrate and has the same size as the outer edge of the N-type substrate; an antireflection film 7 is nested within the central opening of the N-type contact layer, the thickness of which is less than that of the N-type contact layer, and the antireflection film is located at the center of the bottom of the N-type substrate 8; the N-type DBR 9 is located at the top of the N-type substrate and has the same size as the N-type substrate; the quantum well active region 10 is located at the center of the top of the N-type DBR; the oxide window 11 is located at the top of the quantum well active region and has the same size as the outer edge of the quantum well active region; the P-type DBR 12 is located at the top of the oxide window and has the same size as the outer edge of the oxide window; the P-type contact layer 13 is located at the top of the P-type DBR and has the same size as the P-type DBR. It should be noted that the outer edges of the N-type contact layer 6, the N-type substrate 8, and the N-type DBR 9 are all the same size, as are the outer edges of the quantum well active region 10, the oxide window 11, the P-type DBR 12, and the P-type contact layer 13.
[0043] In this application, the laser array, lens layer, and passive phase-change radio frequency switch are distributed sequentially from top to bottom at intervals. Further, the laser array, collimating lens, focusing lens, and passive phase-change radio frequency switch are distributed in parallel intervals from top to bottom. Specifically, the phase-change radio frequency switch is arranged sequentially from top to bottom as follows: laser array, collimating lens, focusing lens, passivation layer, electrode layer, phase change layer, heat dissipation layer, and substrate layer. More specifically, the phase-change radio frequency switch is arranged sequentially from top to bottom as follows: P-type contact layer, P-type DBR, oxide window, quantum well active region, N-type DBR, N-type substrate, antireflection film, N-type contact layer, collimating lens, focusing lens, passivation layer, electrode layer, phase change layer, heat dissipation layer, and substrate layer.
[0044] The materials selected for each layer are as follows:
[0045] The material of the P-type contact layer 13 is Ti / Pt / Au.
[0046] The material of P-type DBR12 is: multiple pairs of C-doped Al 0.9 Ga 0.1 It is composed of As / GaAs to achieve a high reflectivity of over 99%.
[0047] The material of oxide window 11 is: low refractive index Al. x O y / AlAs.
[0048] The material of the active region 10 of the quantum well is: In 0.2Ga 0.8 As and GaAs.
[0049] The material of N-type DBR9 is: multiple pairs of Si-doped Al 0.9 Ga 0.1 Composed of As / GaAs, it provides high reflectivity for lasers of specific wavelengths.
[0050] The material of the N-type substrate 8 is GaAs.
[0051] The antireflective coating 7 is made of Si3N4 and SiO, which have high transmittance. x Hybrid membrane or HfO2 thin film.
[0052] The N-type contact layer 6 is made of Ge / Ni / Au.
[0053] The passivation layer 18 is made of SiO2. SiO2 is an insulating material with good light transmittance, which can reduce the energy loss of the laser and facilitate the laser beam to penetrate the passivation layer with less energy loss and irradiate the phase change layer, helping the phase change to heat up quickly and undergo a phase change.
[0054] The electrode layer 17 is made of at least one of Au, Ag, Cu, Pt, Ti, Cr, ITO, polyphene and graphene. Considering light transmittance, a transparent electrode material can be used, which can improve the light excitation efficiency and speed up the switching speed.
[0055] The phase change layer 16 is made of at least one of vanadium oxide and chalcogenide compounds. In addition to the resistivity of the material itself, reasonable length, width and thickness parameters must be considered during the design. While ensuring that the on-resistance is as small as possible, the spacing between the two RF electrodes is also taken into account so that the off-state capacitance value is also small.
[0056] The heat dissipation layer 15 is made of at least one of AlN, Si3N4, titanium oxide and aluminum oxide. It uses a material with high thermal conductivity and insulation to ensure that the phase change layer can be rapidly annealed during the amorphization process, thereby preventing recrystallization.
[0057] The substrate 14 is made of at least one of SiO2, Si, Sapphire, SiC, GaN and GaAs.
[0058] It should be noted that the laser is grown using MOCVD. The laser beam generated by the laser is successively irradiated onto the passive phase-change RF switch by a collimating lens and a focusing lens, forming different laser beam paths 5.
[0059] It should also be noted that the layers in the passive phase-change RF switch and the laser are processed sequentially from bottom to top using coating and photolithography. The specific coating and photolithography processes are set according to the specific materials of each layer.
[0060] The aforementioned optically induced integrated phase-change RF switch comprises a spaced laser array, a lens layer, and a passive phase-change RF switch. The emitted laser from the laser array passes through the lens layer and then enters the passive phase-change RF switch. Compared to existing electrically excited phase-change RF switches, the optically excited phase-change RF switch in this application offers a faster switching speed, reaching the nanosecond level. Furthermore, by reducing the complexity of the heater design, the isolation of the switch is further improved. Simultaneously, this application arranges multiple VCSEL lasers into a two-dimensional array to increase laser power and uses a collimating lens to collimate the multiple beams before using… The focusing lens converges the collimated beam onto a spot of appropriate size, which can completely cover the phase change layer. In other words, the area of the emitted light from the focusing lens is equal to the area of the phase change layer in the passive phase change RF switch, ensuring the high efficiency of laser energy and providing sufficient phase change energy to the phase change layer to ensure the normal phase change function of the phase change switch. In addition, this application integrates the bottom-emitting laser (i.e., the optical excitation source), the metasurface lens, and the passive phase change RF switch into a single design, which can meet the switching requirements at the micrometer level and has the advantages of simple structure, easy integration, small size, low cost, and high practicality.
[0061] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0062] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.
Claims
1. A light-induced integrated phase-change radio frequency switch, characterized in that, include: Multiple lasers, lens layers, and passive phase-change radio frequency switches; Multiple lasers are spaced apart on the same plane to form a laser array; The lens layer is spaced apart from the laser array and the passive phase-change radio frequency switch, so that the laser emitted from the laser array enters the passive phase-change radio frequency switch after passing through the lens layer. The passive phase-change radio frequency switch comprises, in sequence, a substrate layer, a heat dissipation layer, a phase-change layer, an electrode layer, and a passivation layer; the passivation layer and the lens layer are spaced apart and adjacent to each other. The substrate layer is disposed at the bottom of the heat dissipation layer and is the same size as the heat dissipation layer; The phase change layer is disposed at the top center of the heat dissipation layer and has an area smaller than that of the heat dissipation layer; The electrode layer includes a first part and a second part that are stacked together; the first part is sleeved on the outside of the phase change layer and its outer edge is parallel to the edge of the heat dissipation layer; the first part has the same thickness as the phase change layer so that the top of the first part and the top of the phase change layer are coplanar; the outer edge of the second part has the same size as the heat dissipation layer and forms an opening in the center of the top of the phase change layer. The passivation layer fills the receiving cavity and covers the top of the electrode layer; The laser is a bottom-emitting vertical-cavity surface-emitting laser. The laser comprises, in sequence, an N-type contact layer, an antireflection coating, an N-type substrate, an N-type DBR, a quantum well active region, an oxide window, a P-type DBR, and a P-type contact layer; The N-type contact layer and the antireflective film are both adjacent to the lens layer at intervals.
2. The light-induced integrated phase-change radio frequency switch according to claim 1, characterized in that, The lens layer includes: a collimating lens and a focusing lens; The collimating lens is disposed between the laser array and the focusing lens, and the focusing lens is disposed between the collimating lens and the passive phase-change radio frequency switch.
3. The light-induced integrated phase-change radio frequency switch according to claim 2, characterized in that, The area of the emitted light from the focusing lens is equal to the area of the phase change layer in the passive phase change radio frequency switch.
4. The light-induced integrated phase-change radio frequency switch according to claim 3, characterized in that, Both the collimating lens and the focusing lens are metasurface lenses.
5. The light-induced integrated phase-change radio frequency switch according to claim 4, characterized in that, The laser array, the collimating lens, the focusing lens, and the passive phase-change radio frequency switch are parallel to each other.
6. The photo-induced integrated phase-change radio frequency switch according to any one of claims 1 to 5, characterized in that, The laser is grown using MOCVD.