Photon microwave generation device and signal receiving end

Abstract

The application is suitable for the field of photonic microwave technology, and provides a photonic microwave generating device and a signal receiving end. The photonic microwave generating device comprises a circuit substrate, a microwave photon conversion unit, a grounding capacitor, a power output end, a direct current bias input end, a first bias line output end and a second bias line output end arranged on a first side of the circuit substrate; one end of the microwave photon conversion unit is connected with the power output end, the other end is connected with the first bias line output end, the second bias line output end is connected with the direct current bias input end through the grounding capacitor, and the first bias line output end and the second bias line output end can be connected with an external microstrip line or a coplanar waveguide. The application can realize conversion adjustment and application frequency band by adjusting the external microstrip line or the coplanar waveguide, and can be applied from the microwave to the THz frequency band, and can greatly improve the saturated output power of the microwave photon conversion unit.

Description

Technical Field

[0001] This application belongs to the field of photonic microwave technology, and particularly relates to photonic microwave generating devices and signal receiving terminals. Background Technology

[0002] In a broad sense, terahertz (THz) waves refer to electromagnetic waves with frequencies in the range of 0.1-10 THz, where 1 THz = 1000 GHz. Terahertz waves occupy a very special position in the electromagnetic spectrum, and terahertz technology is recognized by the international scientific community as a very important interdisciplinary frontier field.

[0003] A photodetector is an optoelectronic device that converts incident light signals into electrical signals. It has wide applications in optical communication, especially in fiber optic communication, where it is a key component determining the performance of the entire fiber optic communication system. However, existing photodetectors suffer from problems such as complex circuit structures and limited frequency bands. Summary of the Invention

[0004] To overcome the problems existing in related technologies, this application provides a photonic microwave generating device and a signal receiving end.

[0005] This application is achieved through the following technical solution:

[0006] In a first aspect, embodiments of this application provide a photonic microwave generating device, including a circuit substrate, and a microwave photonic conversion unit, a grounding capacitor, a power output terminal, a DC bias input terminal, a first bias line output terminal, and a second bias line output terminal disposed on a first side of the circuit substrate;

[0007] One end of the microwave photonic conversion unit is connected to the power output terminal, and the other end is connected to the first bias line output terminal. The second bias line output terminal is connected to the DC bias input terminal through the grounding capacitor. The first bias line output terminal and the second bias line output terminal can be connected to an external microstrip line or coplanar waveguide.

[0008] In this embodiment, a microwave photonics conversion unit, a first bias line output terminal, and a second bias line output terminal are integrated on the circuit substrate. The length of the external microstrip line or coplanar waveguide can be calculated and adjusted according to actual needs. Therefore, the application frequency band can be adjusted by regulating the external microstrip line or coplanar waveguide, applicable from microwave to THz frequency bands. Furthermore, a grounding capacitor is integrated on the circuit substrate to apply a negative bias voltage to the microwave photonics conversion unit, facilitating its operation in the optimal DC bias state and significantly improving the saturated output power of the microwave photonics conversion unit.

[0009] Based on the first aspect, in some embodiments, an anti-reflection coating is provided on the second side of the circuit substrate at the position corresponding to the microwave photonic conversion unit.

[0010] Based on the first aspect, in some embodiments, the focused laser signal is input to the area corresponding to the microwave photonic conversion unit on the second side of the circuit substrate. The laser signal is incident on the microwave photonic conversion unit through the circuit substrate. The microwave photonic conversion unit converts the laser signal into a terahertz wave signal, and the terahertz signal is output from the power output terminal.

[0011] Based on the first aspect, in some embodiments, the circuit substrate is an InP circuit substrate.

[0012] Based on the first aspect, in some embodiments, the microwave photonic conversion unit is a single-row carrier photodetector (UTC-PD).

[0013] For example, the anode of the UTC-PD is connected to the power output terminal and the first bias line output terminal, respectively; the cathode of the UTC-PD is connected to the gold-plated ground on the circuit substrate; the gold-plated layer at the bottom of the UTC-PD is connected to the gold-plated ground on the circuit substrate; and an anti-reflective coating is disposed at the bottom of the UTC-PD for receiving laser signals.

[0014] Based on the first aspect, in some embodiments, the grounding capacitor is a MIM grounding capacitor.

[0015] Based on the first aspect, in some embodiments, a matching circuit is further provided on the first side of the circuit substrate between the microwave photonic conversion unit and the power output terminal, and the microwave photonic conversion unit and the power output terminal are connected through the matching circuit.

[0016] Based on the first aspect, in some embodiments, the length of the external microstrip line or coplanar waveguide is calculated based on 1 / 4λ of the center frequency of the terahertz signal operating band; the grounding capacitor is used to AC ground the terahertz signal; the first bias line output terminal, the second bias line output terminal, and the external microstrip line or coplanar waveguide constitute a gating filter, which allows the operating frequency signal to pass through while other AC signals are grounded.

[0017] The aforementioned photonic microwave generating device can achieve independent biasing of the UTC-PD, adjusting it to reach its optimal operating state and obtain the highest saturated output power. On the same InP circuit substrate, by changing the length of the external microstrip line or coplanar waveguide, a microstrip line bias of 1 / 4λ wavelength at the operating frequency can be achieved, enabling power output in different frequency bands and saving grounding capacitors. This photoelectric conversion circuit method has the advantages of simple circuit and convenient use.

[0018] Secondly, embodiments of this application provide a signal receiving end, including a photon microwave generating device as described in any one of the first aspects.

[0019] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this specification. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of a photon microwave generating device provided in an embodiment of this application;

[0022] Figure 2 This is a schematic diagram of the structure of a photon microwave generating device provided in another embodiment of this application;

[0023] Figure 3 This is a schematic diagram of the structure of a UTC-PD provided in an embodiment of this application. Detailed Implementation

[0024] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0025] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0026] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0027] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0028] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0029] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0030] Early research on high-speed, high-power photodetectors focused on improvements to traditional PIN photodetectors. However, these detectors suffer from a trade-off between response speed and responsivity, and the space charge effect under high injected light intensity limits the saturated output photocurrent. Uni-Traveling-Carrier (UTC) structures utilize only electrons as active carriers; light absorption occurs not in the intrinsic region but in the doped P-region, where heavier holes contribute no to the photocurrent. UTC-PD (Uni-Traveling-Carrier Photodetector) is an alternative for high-speed, high-power photodetectors. It uses only electrons as active carriers, effectively suppressing the space charge effect. Unlike PIN devices, UTC-PDs employ P-doped absorption layers and wide-bandgap materials in the collection layer, along with a blocking layer to prevent electrons from entering the anode, creating a single electron transport channel. This effectively weakens the space charge effect, significantly improving the device's high-speed and high-saturation characteristics to meet the demands of modern photodetectors.

[0031] This application provides a photonic microwave generating device, including a circuit substrate, and a microwave photonic conversion unit, a grounding capacitor, a power output terminal, a DC bias input terminal, a first bias line output terminal, and a second bias line output terminal disposed on a first side of the circuit substrate. One end of the microwave photonic conversion unit is connected to the power output terminal, and the other end is connected to the first bias line output terminal. The second bias line output terminal is connected to the DC bias input terminal through the grounding capacitor. The first bias line output terminal and the second bias line output terminal can be connected to an external microstrip line or a coplanar waveguide.

[0032] In this embodiment, a microwave photonics conversion unit, a first bias line output terminal, and a second bias line output terminal are integrated on the circuit substrate. The length of the external microstrip line or coplanar waveguide can be calculated and adjusted according to actual needs. Therefore, the application frequency band can be adjusted by regulating the external microstrip line or coplanar waveguide, applicable from microwave to THz frequency bands. Furthermore, a grounding capacitor is integrated on the circuit substrate to apply a negative bias voltage to the microwave photonics conversion unit, facilitating its operation in the optimal DC bias state and significantly improving the saturated output power of the microwave photonics conversion unit.

[0033] The photon microwave generating apparatus of the present application will be described in detail below.

[0034] See Figure 1 and Figure 2 The aforementioned photon-microwave generating device may include: a circuit substrate 10, a microwave-photon conversion unit 14, a grounding capacitor 17, a power output terminal 12, a DC bias input terminal 18, a first bias line output terminal 15, and a second bias line output terminal 16. The microwave-photon conversion unit 14, the grounding capacitor 17, the power output terminal 12, the DC bias input terminal 18, the first bias line output terminal 15, and the second bias line output terminal 16 are disposed on a first side of the circuit substrate 10.

[0035] The microwave photonic conversion unit 14 is connected at one end to the power output terminal 12 and at the other end to the first bias line output terminal 15. The second bias line output terminal 16 is connected to the DC bias input terminal 18 through the grounding capacitor 17. The first bias line output terminal 15 and the second bias line output terminal 16 can be connected to an external microstrip line or coplanar waveguide 100.

[0036] For example, an anti-reflection coating 19 is provided on the second side of the circuit substrate 10 at a position corresponding to the microwave photonic conversion unit 14.

[0037] For example, the circuit substrate 10 can be an InP (indium phosphide) circuit substrate.

[0038] For example, the microwave photonic conversion unit 14 can be a UTC-PD (Uni-Traveling-Carrier Photodetector).

[0039] This InGaAs / InP UTC-PD structure was grown layer-by-layer on a semi-insulating InP substrate using metal-organic chemical vapor deposition (MOCVD). See also Figure 3 The structure of a UTC-PD includes: an InP substrate, a gold-plated layer disposed on the outer periphery of the lower side of the InP substrate, an anti-reflective coating disposed in the middle of the lower side of the InP substrate, a sub-collector layer disposed on the upper side of the InP substrate, a cathode disposed on the outer periphery of the upper side of the sub-collector layer, a collector layer, a cliff layer, a transition layer, an absorber layer, a barrier layer, and an ohmic contact layer disposed sequentially in the middle of the upper side of the sub-collector layer, and an anode disposed on the ohmic contact layer. The thickness and doping concentration of each layer are detailed in relevant technologies and will not be elaborated here.

[0040] For example, the UTC-PD can penetrate the circuit substrate 10, the anode at the top of the UTC-PD can be exposed on the first side of the circuit substrate 10, and the anti-reflective coating at the bottom of the UTC-PD can be exposed on the second side of the circuit substrate 10, with the first side and the second side opposite to each other.

[0041] In this embodiment, the anode of the UTC-PD is connected to the power output terminal 12 and the first bias line output terminal 15, respectively. The cathode of the UTC-PD is connected to the gold-plated ground on the circuit substrate 10. The gold-plated layer at the bottom of the UTC-PD is connected to the gold-plated ground on the circuit substrate 10. The anti-reflection coating 19 is disposed at the bottom of the UTC-PD for receiving laser signals.

[0042] For example, such a mesa vertical incident back-illuminated device can be processed by conventional photolithography, metal stripping and wet chemical etching, followed by thinning and polishing of the back side of the InP substrate, and then deposition of an anti-reflective coating 19.

[0043] For example, grounding capacitor 17 can be a MIM grounding capacitor.

[0044] For example, on the first side of the circuit substrate 10, a matching circuit 13 is also provided between the microwave photonics conversion unit 14 and the power output terminal 12, and the microwave photonics conversion unit 14 and the power output terminal 12 are connected through the matching circuit 13. Specifically, the anode of the UTC-PD is connected to the power output terminal 12 through the matching circuit 13.

[0045] A negative voltage is applied to the DC bias input terminal 18; the laser signal (e.g., a 1550nm laser signal) passing through the fiber optic head is focused by a lens and directed onto the anti-reflective coating 19 on the second side of the InP circuit substrate 10. The laser signal is incident on the circular area shown on the first side 14 of the InP circuit substrate 10, which includes the UTC-PD's collection layer, cliff layer, transition layer, and absorption layer. The UTC-PD's cathode is grounded. In the UTC-PD's collection layer, due to the applied voltage, the photogenerated electrons generated by the laser signal in the absorption layer flow to the cathode, thereby generating a photocurrent flowing to the anode. The converted terahertz wave signal is output through the UTC-PD's anode, and the output terahertz signal is output from the power output terminal 12 through the matching circuit 13.

[0046] The length of the external microstrip line or coplanar waveguide 100 is calculated based on 1 / 4λ (wavelength) of the center frequency of the terahertz signal operating band. The first bias line output terminal 15, the second bias line output terminal 16, and the external microstrip line or coplanar waveguide 100 form a gating filter, which allows the operating frequency signal to pass through while other AC signals are grounded. The terahertz signal is AC grounded through the MIM grounding capacitor, and a DC negative voltage is applied to the positive terminal of the UTC-PD through the DC bias input terminal 18 and the external microstrip line or coplanar waveguide 100, so that the UTC-PD operates in the optimal DC state.

[0047] The photonic microwave generating device provided in this application is a monolithic integrated circuit for converting optical signals into terahertz signals. This circuit configuration allows for independent biasing of the UTC-PD, adjusting it to its optimal operating state and maximizing its saturated output power. Furthermore, the length of the external microstrip line or coplanar waveguide 100 can be calculated and adjusted according to actual needs. On the same InP circuit substrate, by changing the length of the external microstrip line, a microstrip line bias at 1 / 4λ wavelength of the operating frequency can be achieved. Therefore, the application frequency band can be adjusted by modifying the external microstrip line or coplanar waveguide, enabling power output at different frequency bands and saving on grounding capacitors. This photoelectric conversion circuit method has the advantages of simple circuitry and ease of use.

[0048] Optionally, embodiments of this application also provide a signal receiving end, which includes any of the above-mentioned photon microwave generating devices and has all the beneficial effects of the above-mentioned photon microwave generating devices, which will not be repeated here.

[0049] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A photon microwave generating device, characterized in that, The device includes a circuit substrate, and a microwave photonics conversion unit, a grounding capacitor, a power output terminal, a DC bias input terminal, a first bias line output terminal, and a second bias line output terminal disposed on a first side of the circuit substrate; the microwave photonics conversion unit is a single-row carrier photodetector (UTC-PD); an anti-reflection coating is disposed on a second side of the circuit substrate at a position corresponding to the microwave photonics conversion unit; the anti-reflection coating is disposed on the bottom of the UTC-PD for receiving laser signals; One end of the microwave photonic conversion unit is connected to the power output terminal, and the other end is connected to the first bias line output terminal. The second bias line output terminal is connected to the DC bias input terminal through the grounding capacitor. The first bias line output terminal and the second bias line output terminal can be connected to an external microstrip line or a coplanar waveguide. The external microstrip line or the coplanar waveguide is used to adjust the application frequency band by changing its own length.

2. The photon microwave generating device as described in claim 1, characterized in that, The focused laser signal is input to the area on the second side of the circuit substrate corresponding to the microwave photonic conversion unit. The laser signal is incident on the microwave photonic conversion unit through the circuit substrate. The microwave photonic conversion unit converts the laser signal into a terahertz wave signal, and the terahertz signal is output from the power output terminal.

3. The photon microwave generating device as described in claim 1, characterized in that, The circuit substrate is an InP circuit substrate.

4. The photon microwave generating device as described in claim 1, characterized in that, The anode of the UTC-PD is connected to the power output terminal and the first bias line output terminal, respectively. The cathode of the UTC-PD is connected to the gold-plated ground on the circuit substrate, and the gold-plated layer at the bottom of the UTC-PD is connected to the gold-plated ground on the circuit substrate.

5. The photon microwave generating device as described in claim 1, characterized in that, The grounding capacitor is a MIM grounding capacitor.

6. The photon microwave generating device as described in claim 1, characterized in that, On the first side of the circuit substrate, a matching circuit is also provided between the microwave photonic conversion unit and the power output terminal, and the microwave photonic conversion unit and the power output terminal are connected through the matching circuit.

7. The photon microwave generating device as described in claim 1, characterized in that, The length of the external microstrip line or coplanar waveguide is calculated based on 1 / 4λ of the center frequency of the terahertz signal operating band; the grounding capacitor is used to AC ground the terahertz signal; the first bias line output terminal, the second bias line output terminal, and the external microstrip line or coplanar waveguide constitute a gating filter, which allows the operating frequency signal to pass through, while other AC signals are grounded.

8. A signal receiver, characterized in that, Includes the photon microwave generating apparatus as described in any one of claims 1 to 7.

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