Antenna integrated waveguide photodetector and system, method for transmitting a signal - Patents.com

Abstract

The present invention provides an antenna-integrated waveguide photodetector and system, and a method for transmitting a signal, including a photodetector, N optical waveguides, and an antenna, where N is a positive integer, the antenna being provided on a substrate, and a feed gap being provided on the symmetrical axis of both arms of the antenna, the photodetector being provided within the feed gap, and the N optical waveguides being formed on the substrate, the photodetector being connected to the optical waveguides to acquire an optical carrier radio frequency signal transmitted through the optical waveguides. By providing a feed gap on the symmetrical axis of both arms of the antenna and providing the photodetector within the feed gap, the present invention allows the antenna and the photodetector to be integrated on the same device of the same chip, thereby improving the integration degree of optical integrated circuits and systems.

Description

[Technical Field]

[0001] The present invention relates to the technical field of optical integrated circuits, and in particular to a waveguide photodetector and system with integrated antenna and method for transmitting signals. [Background technology]

[0002] A waveguide photodetector is a device that converts optical signals into electrical signals and is commonly used in optical integrated circuits. In some microwave photon applications, an optical signal passes through a waveguide photodetector, is absorbed by the waveguide photodetector, and is converted into an electrical signal, which then needs to be immediately emitted into free space.

[0003] The conventional approach is to add a transmitting antenna outside the photodetector chip and package it into a single system, but this release has low integration, complex packaging, and high costs.

[0004] Therefore, the present invention provides an antenna integrated waveguide photodetector and system for transmitting a signal to improve the integration of microwave photonic systems. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention provides an antenna integrated waveguide photodetector and system for improving the integration of microwave photonic systems, and a method for transmitting signals. [Means for solving the problem]

[0006] According to a first aspect, the present invention provides an antenna-integrated waveguide photodetector, comprising: a photodetector, N optical waveguides, and an antenna, where N is a positive integer; the antenna is provided on a substrate, and a feed gap is provided at a symmetrical axis position of both arms of the antenna, the photodetector is provided in the feed gap, the N optical waveguides are formed on the substrate, and the photodetector is connected to the optical waveguides to acquire an optical carrier radio frequency signal transmitted on the optical waveguides.

[0007] The beneficial effect of the present invention is that the antenna and the photodetector can be integrated on the same device of the same chip by providing a feed gap at the symmetrical axis position of both arms of the antenna and providing the photodetector in the feed gap, thereby improving the integration of the optical integrated circuit and system.

[0008] Optionally, the photodetector is matched to the operating frequency of the antenna, the beneficial effect of which is that matching the photodetector to the operating frequency of the antenna helps to make both work better together and improves the operating efficiency of the waveguide photodetector in which the antenna is integrated, as described above.

[0009] Optionally, the antenna includes at least one of a Vivaldi antenna, a bowtie antenna, a slot antenna, and a patch antenna, which has a beneficial effect in that the antenna has multiple design styles, so that the type of the antenna can be modified to meet actual production needs, such as the need for antenna radiation area.

[0010] Further optionally, the substrate comprises at least one of silicon, silicon-on-insulator, silicon-on-sapphire, silica, indium phosphide, lithium niobate, and polymer, which has a beneficial effect that the aforementioned waveguide photodetector with integrated antenna can be integrated on a substrate made of any one or more of the above materials to meet actual production needs.

[0011] Further optionally, the operating frequency of the antenna includes an L-band frequency range, an S-band frequency range, a C-band frequency range, an X-band frequency range, a Ku-band frequency range, a K-band frequency range, a KA-band frequency range, and a terahertz frequency range, which has a beneficial effect in that the operating frequency of the antenna includes multiple frequency types, so that the aforementioned waveguide photodetector integrated with the antenna can process signals in different frequency ranges.

[0012] Optionally, the type of the optical waveguide includes at least one of a channel waveguide, a ridge waveguide, a slot waveguide, a diffusion waveguide, and a photonic crystal waveguide, and the beneficial effect is that the type of the optical waveguide includes multiple types, and different types of waveguides have different cross-sectional areas, so that a suitable optical waveguide type can be selected according to actual production needs.

[0013] Optionally, the photodetector comprises at least one of a metal photodetector, a semiconductor photodetector, a metal-semiconductor photodetector, and an avalanche photodetector.

[0014] Optionally, the wavelength range of the optical signal includes at least one of a visible light band, an O-band, an E-band, an S-band, a C-band, an L-band, a U-band, and a mid-infrared band.

[0015] According to a second aspect, the present invention provides an antenna-integrated waveguide photodetector integrated system including K antenna-integrated waveguide photodetectors according to any one of the embodiments of the first aspect arranged in an array, wherein K is a positive integer equal to or greater than 2.

[0016] The beneficial effect is that the aforementioned antenna integrated waveguide photodetector integrated system can be used in phased array radar applications to complete target search, tracking and measurement.

[0017] According to a third aspect, the present invention provides a method for transmitting a signal, the method including: applying an antenna according to any one of the embodiments of the first aspect to a waveguide photodetector integrated with the antenna; the optical waveguide acquiring an optical carrier radio frequency signal and transmitting the optical carrier radio frequency signal to the photodetector; the photodetector receiving the optical carrier radio frequency signal from the optical waveguide, converting the optical carrier radio frequency signal to an electrical radio frequency signal and transmitting the electrical radio frequency signal to the antenna; and the antenna acquiring the electrical radio frequency signal from the photodetector and transmitting the electrical radio frequency signal.

[0018] The beneficial effect is that by applying the present invention to the waveguide photodetector integrated with the antenna described in any one of the above embodiments, the integration degree of the optical integrated circuit can be improved while ensuring the signal transmission efficiency to meet the needs of actual production.

[0019] Optionally, the aforementioned method for transmitting a signal further includes obtaining a frequency range of the electrical radio frequency signal, and if the frequency range of the electrical radio frequency signal does not meet a preset requirement, modifying or adjusting a design of at least one of the antenna and the photodetector so that the frequency range of the electrical radio frequency signal meets the preset requirement, the beneficial effect of which is that by modifying or adjusting the design of the antenna and the photodetector, the frequency range of the electrical radio frequency signal meets actual needs.

[0020] Optionally, the method for transmitting a signal as described above includes adjusting the design of the antenna based on a radiation diagram so that the radiation direction of the electrical radio frequency signal meets the preset requirements. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a schematic diagram of an embodiment of a waveguide photodetector with an integrated antenna according to the present invention; [Figure 2]FIG. 10 is a schematic diagram of another antenna-integrated waveguide photodetector embodiment according to the present invention. [Figure 3] 1 is a schematic diagram of an embodiment of a waveguide photodetector integrated system in which an antenna according to the present invention is integrated; [Figure 4] 4 is a method flowchart for transmitting a signal according to the present invention; [Figure 5] 1 is a schematic diagram of an example of a simulation result of the radiation diagram of a Vivaldi antenna according to the present invention; [Figure 6] 1 is a schematic diagram of an example of simulation results of photodetector performance according to the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0022] The following describes technical solutions in the embodiments of the present application in conjunction with the accompanying drawings in the embodiments of the present application. Herein, in describing the embodiments of the present application, the terms used in the following embodiments are intended only to describe specific embodiments and are not intended to limit the present application. As used in the specification and appended claims of the present application, the singular forms "a," "the," "the," "the," and "the" are intended to include other forms such as "one or more," unless the context clearly dictates otherwise. In the following embodiments of the present application, "at least one" and "one or more" refer to one or more (including two). The term "and / or" is used to describe a relationship between related objects and indicates that three relationships may exist. For example, A and / or B may include three cases: A alone, a combination of A and B, and B alone, where A and B may be singular or plural. The character " / " generally indicates that the related objects before and after it are in an "or" relationship.

[0023] References herein to "one embodiment" or "some embodiments" mean that one or more embodiments of the present application include the particular feature, structure, or characteristic described in connection with that embodiment. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in some embodiments" appearing in different places herein do not necessarily all refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise emphasized. The terms "comprise," "contain," "have," and variations thereof mean "including, but not limited to," unless otherwise emphasized. The term "connected" includes direct and indirect connections unless otherwise stated. The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or suggesting relative importance or implicitly denoting the number of technical features indicated.

[0024] In the embodiments of the present application, terms such as "exemplary" or "for example" are used to denote an example, illustration, or explanation. In the embodiments of the present application, any embodiment or design solution described as "exemplary" or "for example" should not be construed as preferred or advantageous over other embodiments or design solutions. Rather, the use of terms such as "exemplary" or "for example" is intended to present related concepts in a concrete manner.

[0025] In order to improve the integration degree of optical integrated circuits, the present invention provides an antenna-integrated waveguide photodetector, as shown in FIG. 1, including a photodetector 1, N optical waveguides (as shown in FIG. 1 as the optical waveguide 2), and an antenna 3, where N is a positive integer, the antenna 3 is provided on a substrate, and a feed gap is provided at the symmetrical axis position of both arms of the antenna 3, the photodetector 1 is provided in the feed gap, and the N optical waveguides (as shown in FIG. 1 as the optical waveguide 2) are formed on the substrate, and the photodetector 1 is connected to the optical waveguide 2 to acquire an optical carrier radio frequency signal transmitted on the optical waveguide 2.

[0026] In this embodiment, only the optical waveguide 2 is taken as an example to describe the structure of the waveguide photodetector integrated with the antenna, and the number of optical waveguides to which the photodetector can be connected in Fig. 1 is not limited, and N is set according to actual needs, and N may be 1 or more. In the present invention, a feed gap is provided at the symmetrical axis position of both arms of the antenna 3, and the photodetector 1 is provided within the feed gap, so that the antenna 3 and the photodetector 1 can be integrated on the same chip, thereby improving the integration degree of the optical integrated circuit.

[0027] In one possible embodiment, the photodetector is matched to the operating frequency of the antenna, which in this embodiment helps to make both work better together and improves the operating efficiency of the waveguide photodetector in which the antenna is integrated, as described above.

[0028] In another possible embodiment, the antenna includes at least one of a Vivaldi antenna, a bowtie antenna, a slot antenna, and a patch antenna. In this embodiment, the antenna has multiple design modes, so the type of the antenna can be modified to meet actual production needs, such as the antenna radiation area requirements. For example, the antenna shown in FIG. 1 is a Vivaldi antenna, and the antenna shown in FIG. 2 is a bowtie antenna. That is, the antenna-integrated waveguide photodetector shown in FIG. 2 includes a photodetector 1, an optical waveguide 2, and an antenna 4, and the antenna 4 is a bowtie antenna. This embodiment meets different application needs by modifying the antenna type in the antenna-integrated waveguide photodetector described above.

[0029] In a further possible embodiment, the substrate comprises at least one of silicon, silicon-on-insulator, silicon-on-sapphire, silica, indium phosphide, lithium niobate, and polymer. In this embodiment, the above-mentioned antenna-integrated waveguide photodetector can be integrated on a substrate made of any one or more of the above materials to meet actual production needs.

[0030] In one possible embodiment, the antenna's operating frequency range includes the L-band frequency range, S-band frequency range, C-band frequency range, X-band frequency range, Ku-band frequency range, K-band frequency range, KA-band frequency range, and terahertz frequency range. The X-band refers to a radio wave band with a frequency of 8 to 12 GHz, which belongs to the microwave band in the electromagnetic spectrum. In some cases, the X-band frequency range may be 7 to 11.2 GHz. The Ku-band frequency range is 12 to 18 GHz. The aperture of an antenna for receiving the Ku-band radio waves is relatively small, thereby effectively reducing reception costs. The terahertz frequency range includes electromagnetic waves with a frequency of 0.1 to 10 THz. Terahertz refers to frequencies between the high-frequency edge of the millimeter wave band (300 GHz) and the low-frequency edge of the far-infrared spectrum band (3000 GHz) emitted from electromagnetic waves, and the corresponding wavelength radiation is 0.03 mm to 3 mm (or 30 to 3000 μm) in this frequency band range. The photon energy at a frequency of 1 THz is only about 4 millielectron volts, which is unlikely to destroy the substance to be detected. In this embodiment, the operating frequency of the antenna includes multiple frequency types, so that the waveguide photodetector integrated with the antenna can process optical signals in different frequency ranges.

[0031] In another possible embodiment, the type of the optical waveguide includes at least one of a channel waveguide, a ridge waveguide, a slot waveguide, a diffused waveguide, and a photonic crystal waveguide, where common optical waveguide types are a channel waveguide and a ridge waveguide, and in this embodiment, the type of the optical waveguide includes multiple types, and different types of waveguides have different cross-sectional areas, so that an appropriate optical waveguide type can be selected according to actual production needs.

[0032] In further possible embodiments, the photodetector comprises at least one of a metal photodetector, a semiconductor photodetector, a metal-semiconductor photodetector, and an avalanche photodetector. Different types of photodetectors are suitable for different applications.

[0033] In one possible embodiment, the wavelength range of the optical signal comprises at least one of the visible light band, the O band, the E band, the S band, the C band, the L band, the U band, and the mid-infrared band.

[0034] Based on the antenna-integrated waveguide photodetector according to any one of the above embodiments, the present invention provides an antenna-integrated waveguide photodetector integrated system including K antenna-integrated waveguide photodetectors according to any one of the above embodiments arranged in an array, where K is a positive integer equal to or greater than 2.

[0035] As shown in FIG. 3 , the antenna-integrated waveguide photodetector integrated system includes nine antenna-integrated waveguide photodetectors 100 arranged in a matrix, where K is a positive integer greater than or equal to 2. Therefore, the antenna-integrated waveguide photodetector integrated system includes at least two antenna-integrated waveguide photodetectors, and the array of antenna-integrated waveguide photodetectors may have an irregular shape. The antenna-integrated waveguide photodetector integrated system can be used in phased array radar applications to complete target search, tracking, and measurement. The antenna-integrated waveguide photodetector improves the integration density of optical integrated devices. Therefore, constructing the antenna-integrated waveguide photodetector integrated system from the antenna-integrated waveguide photodetector also improves the integration density of optical integrated devices and systems.

[0036] In addition, based on the above-mentioned antenna-integrated waveguide photodetector according to any one of the above embodiments, the present invention provides a method for transmitting a signal, the method flow of which is shown in FIG. 4, and the specific steps include:

[0037] S401, the optical waveguide receives an optical carrier radio frequency signal and transmits the optical carrier radio frequency signal to the photodetector.

[0038] S402, the photodetector receives the optical carrier radio frequency signal from the optical waveguide, converts the optical carrier radio frequency signal into an electrical radio frequency signal, and transmits the electrical radio frequency signal to the antenna.

[0039] S403, the antenna acquires the electrical radio frequency signal from the photodetector and transmits the electrical radio frequency signal.

[0040] The present invention can be applied to the method for transmitting signals using a waveguide photodetector integrated with an antenna as described in any one of the above embodiments, thereby ensuring signal transmission efficiency and improving the integration degree of optical integrated circuits to meet actual production needs.

[0041] In one possible embodiment, the method for transmitting a signal as described above further includes obtaining a frequency range of the electrical radio frequency signal, and if the frequency range of the electrical radio frequency signal does not meet a predetermined requirement, modifying or adjusting a design of at least one of the antenna and the photodetector so that the frequency range of the electrical radio frequency signal meets the predetermined requirement. In this embodiment, the frequency range of the electrical radio frequency signal is adapted to actual needs by modifying at least one of the size of the antenna, the RC parameter of the photodetector, and the carrier transit time of the photodetector. In one possible embodiment, the method for transmitting a signal as described above further includes adjusting a design of the antenna based on a required radiation diagram. For example, if the antenna used is a Vivaldi antenna and its outline is as shown in (a), (b), and (c) in Figure 5, a feed gap is provided between the first and second arms of the antenna, and a photodetector is provided in the feed gap. The radiation diagrams of the waveguide photodetector with the integrated antenna are shown in (A), (B), and (C) in Figure 5, respectively. "y" in Figure 5 represents the y-axis of the coordinate system, "z" in Figure 5 represents the z-axis of the coordinate system, and the x-axis (not shown) is perpendicular to the plane on which the y-axis and z-axis are located. In (A), (B), and (C) in Figure 5, the solid lines represent the radiation diagrams of the waveguide photodetector with the integrated antenna corresponding to the yz plane, and the dashed lines represent the radiation diagrams of the waveguide photodetector with the integrated antenna corresponding to the xy plane.

[0042] The specific structure of the photodetector and the absorbing material on the photodetector mentioned herein are not limited. For example, the absorbing material can include germanium, silicon, III-V materials, and metals. The specific location of the contact on the photodetector for connection to the antenna is not limited. When the absorbing material on the photodetector is germanium, simulation results of the performance of the photodetector are shown in FIG. 6. The horizontal axis of (a) in FIG. 6 represents the light propagation distance in microns (um). The vertical axis of (a) in FIG. 6 represents the normalized total absorption efficiency. (a) in FIG. 6 shows how the normalized total absorption efficiency changes with the light propagation distance in the absorption region. (b) in FIG. 6 represents the wavelength in nanometers (nm). The vertical axis of (b) in FIG. 6 represents the photoresponsivity. (b) in FIG. 6 shows how the photoresponsivity changes with the wavelength near the O-band.

[0043] Although the above description is merely a specific embodiment of the examples of the present application, the scope of protection of the examples of the present application is not limited thereto, and any modifications or replacements within the technical scope set forth in the examples of the present application should be included in the scope of protection of the examples of the present application. Therefore, the scope of protection of the examples of the present application should be based on the scope of protection of the claims.

Claims

1. An antenna-integrated waveguide photodetector including a photodetector, N optical waveguides, and an antenna, wherein N is a positive integer; the antenna is provided on one substrate, and a feed gap is provided at a symmetrical axis position of both arms of the antenna, and the photodetector is provided in the feed gap; a number N of the optical waveguides formed on the substrate, and the photodetector connected to the optical waveguides to acquire an optical carrier radio frequency signal transmitted on the optical waveguides.

2. 2. The antenna integrated waveguide photodetector of claim 1, wherein the photodetector matches the operating frequency of the antenna.

3. 2. The antenna integrated waveguide photodetector of claim 1, wherein the antenna comprises at least one of a Vivaldi antenna, a bowtie antenna, a slot antenna, and a patch antenna.

4. 10. The antenna-integrated waveguide photodetector of claim 1, wherein the substrate comprises at least one of silicon, silicon-on-insulator, silicon-on-sapphire, silica, indium phosphide, lithium niobate, and a polymer.

5. 2. The antenna-integrated waveguide photodetector of claim 1, wherein the operating frequency range of the antenna includes an L-band frequency range, an S-band frequency range, a C-band frequency range, an X-band frequency range, a Ku-band frequency range, a K-band frequency range, a KA-band frequency range, and a terahertz frequency range.

6. 2. The antenna-integrated waveguide photodetector of claim 1, wherein the type of the optical waveguide includes at least one of a channel waveguide, a ridge waveguide, a slot waveguide, a diffused waveguide, and a photonic crystal waveguide.

7. 10. The antenna integrated waveguide photodetector of claim 1, wherein the photodetector comprises at least one of a metal photodetector, a semiconductor photodetector, a metal-semiconductor photodetector, and an avalanche photodetector.

8. 2. The antenna-integrated waveguide photodetector of claim 1, wherein the wavelength range of the optical signal includes at least one of a visible light band, an O-band, an E-band, an S-band, a C-band, an L-band, a U-band, and a mid-infrared band.

9. 9. An antenna-integrated waveguide photodetector integrated system, comprising: K antenna-integrated waveguide photodetectors according to any one of claims 1 to 8, arranged in an array, wherein K is a positive integer of 2 or greater.

10. The antenna according to any one of claims 1 to 8 is applied to an integrated waveguide photodetector; the optical waveguide receives an optical carrier radio frequency signal and transmits the optical carrier radio frequency signal to the photodetector; the photodetector receiving the optical carrier radio frequency signal from the optical waveguide, converting the optical signal to an electrical radio frequency signal, and transmitting the electrical radio frequency signal to the antenna; the antenna acquiring the electrical radio frequency signal from the photodetector and transmitting the electrical radio frequency signal.

11. 11. The method of transmitting a signal according to claim 10, further comprising: obtaining a frequency range of the electrical radio frequency signal; and, if the frequency range of the electrical radio frequency signal does not meet a predetermined requirement, modifying or adjusting a design of at least one of the antenna and the photodetector so that the frequency range of the electrical radio frequency signal meets the predetermined requirement.

12. 12. The method of claim 11, further comprising adjusting the design of the antenna based on a radiation diagram so that the radiation direction of the electrical radio frequency signal meets the predetermined requirements.

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