0-threshold pressure photoelectric integrated sensor, preparation method thereof and sensing system

Abstract

The invention discloses a 0-threshold pressure photoelectric integrated sensor, a preparation method thereof and a sensing system, and belongs to the technical field of sensors. The sensor comprises a silicon substrate, a buffer layer, a GaN channel layer, an AlN insertion layer, an AlGaN barrier layer and a GaN cover layer, pressure signal sensing is realized by utilizing a piezoelectric effect of two-dimensional electron gas, a photosensitive two-dimensional material is transferred in a grid electrode region and a source electrode region of the pressure sensor through a transfer process, and a pressure-photoelectric integrated response structure is constructed; besides, the sensor can reach the maximum sensitivity at 0V, so that an extra power supply is not needed to independently supply power to the grid, and the complexity and the sensitivity of a wireless power supply system are effectively balanced. By constructing an independent pressure and photoelectric signal detection channel, a pressure and photoelectric two-parameter sensing function is integrated on the same device, and no cross interference exists between the two sensing units, so that the independence and stability of a detection signal are ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to a 0-threshold pressure, photoelectric integrated sensor and a preparation method thereof and a sensing system, and belongs to the technical field of sensors. BACKGROUND

[0002] Modern sensor technology is developing rapidly towards multi-dimensional perception, low-power operation and intelligent processing. In particular, in complex environmental monitoring scenarios, the collection of a single physical quantity has been difficult to support accurate decision-making - for example, in intelligent manufacturing workshops, not only is it necessary to monitor the pressure changes caused by equipment vibration in real time, but also it is necessary to judge the running state of the production line lighting system through light intensity; in intelligent medical devices, not only is it necessary to capture the pressure signals of the human body pulse, but also it is necessary to monitor the blood oxygen saturation by means of photoelectric sensing.

[0003] Pressure sensors and photoelectric sensors, as two types of core sensing devices, have been widely used in industrial control, environmental monitoring, smart home, biological medicine and other key fields. The former realizes the quantization of force signals through piezoelectric effect or resistance strain principle, and the latter completes the conversion of light intensity and electrical signals relying on photodiodes or CMOS arrays, both of which have shown mature technical advantages in their respective fields.

[0004] However, in the current mainstream scheme, the two types of sensors exist in the form of independent modules, and separate data acquisition links and processing units are used. This architecture not only leads to redundant device size and rising energy consumption, but more importantly, it lacks a decoupling mechanism across physical quantities - when pressure changes are accompanied by temperature fluctuations causing light signal drift, or strong light irradiation interferes with the pressure sensitive element, the independent system cannot distinguish the cross interference sources, and is prone to data misjudgment. This limitation seriously restricts the accuracy of multi-parameter collaborative perception in complex scenarios, and it is difficult to meet the needs of comprehensive research and judgment of environmental situation in high-end manufacturing, intelligent security and other fields. SUMMARY

[0005] In order to realize the integrated design of photoelectric and pressure sensors, and at the same time realize the decoupling of the two sensors, the present application provides a 0-threshold pressure, photoelectric integrated sensor and a preparation method thereof and a sensing system, and the technical solution is as follows:

[0006] The first purpose of the present application is to provide a pressure, photoelectric integrated sensor, characterized in that the basic levels of the sensor from bottom to top include: a silicon substrate 101, a buffer layer 102, a GaN channel layer 103, an AlN insertion layer 104, an AlGaN barrier layer 105, and a GaN cap layer 106;

[0007] The source and the drain respectively penetrate the GaN cap layer 106 and are connected with the AlGaN barrier layer 105 through ohmic contact, and are located on both sides of the pressure sensitive area;

[0008] The gate is located between the source and drain, and forms a Schottky contact with the AlGaN barrier layer 105 through the GaN capping layer 106;

[0009] The silicon substrate 101 and buffer layer 102 form an opening at the bottom of the sensor and are bonded to the pdms material, forming a sealed cavity with the bottom of the GaN channel layer 103.

[0010] Optionally, the buffer layer 102 includes, from bottom to top, an AlN buffer layer, an AlGaN buffer layer, and a GaN buffer layer.

[0011] Optionally, the source and drain electrodes are formed by stacking Ti / Al / Ni / Au metals.

[0012] Optionally, the gate is made of Ni / Au metal.

[0013] A second objective of this invention is to provide a method for fabricating a pressure and photoelectric integrated sensor, the method comprising:

[0014] Step 1: A buffer layer 102, a GaN channel layer 103, an AlN insertion layer 104, an AlGaN barrier layer 105, and a GaN capping layer 106 are sequentially formed on a silicon substrate 101.

[0015] Step 2: Etch the edges of the GaN capping layer 106, AlGaN barrier layer 105, AlN insertion layer 104, and GaN channel layer 103 from the top, and stop etching at the middle of the GaN channel layer 103 to isolate the two-dimensional electron gas between the devices.

[0016] Step 3: Etch the source and drain regions of the GaN capping layer 106 to expose the upper surface of the AlGaN barrier layer 105, sputter metal on the AlGaN barrier layer 105 to form ohmic contacts, and anneal to form the source and drain.

[0017] Step 4: Etch the GaN capping layer 106 and the AlGaN barrier layer 105 in the gate region, and sputter metal on the AlGaN barrier layer 105 to form the gate.

[0018] Step 5: Photolithography of wires, followed by sputtering of metal material after development;

[0019] Step 6: The silicon substrate 101 and buffer layer 102 at the bottom of the photolithography device expose the lower surface of the GaN channel 103, forming an opening;

[0020] Step 7: Bond the sensor to the PDMS using bonding technology to form a sealed cavity.

[0021] Optionally, after etching in step 4, a 10nm AlGaN barrier layer thickness of 105 is retained.

[0022] The third objective of this invention is to provide a wirelessly powered pressure and photoelectric integrated sensing system, characterized in that the system comprises: an antenna, a rectifier, and a pressure and photoelectric integrated sensor as described in any of the preceding claims;

[0023] The antenna is used to receive wirelessly transmitted energy signals and convert them into electrical signals. The rectifier is connected to the output terminal of the antenna and is used to filter the electrical signals output by the antenna and convert the AC signals into DC signals to provide power to the pressure and photoelectric integrated sensor. The gate and source of the pressure and photoelectric integrated sensor are connected to the output terminal of the rectifier, and the source and drain of the pressure and photoelectric integrated sensor are respectively connected to the output terminal of the rectifier, thus constructing independent signal processing channels for the gate-source current and source-drain current.

[0024] Optionally, the antenna is a broadband circularly polarized microstrip monopole antenna.

[0025] Optionally, the antenna includes a radiating element and a feeding network. The radiating element receives electromagnetic waves and converts the energy of the electromagnetic waves into high-frequency electrical signals, and the feeding network transmits the high-frequency electrical signals to the receiving device.

[0026] Optionally, the rectifier is a microwave rectifier based on microstrip lines and lumped elements, which realizes the conversion from radio frequency to DC through transmission line matching, diode rectification, and capacitor filtering.

[0027] Beneficial effects:

[0028] The sensor structure designed in this invention can simultaneously detect light and pressure signals. Compared to existing single-function sensors (that can only detect light or only detect pressure), this invention can achieve simultaneous light and pressure sensing on the same device without complicating the structure. Furthermore, by integrating light-sensitive two-dimensional materials onto the sensor surface using transfer technology, it can achieve sensing functions for both visible and invisible light. In addition, etching gate grooves or thinning the AlGaN as a whole can precisely control the transistor threshold near 0V, allowing both pressure and photoelectric sensors to reach maximum sensitivity at 0V. This eliminates the need for an additional power supply to power the gate, effectively balancing the complexity and sensitivity of powering three-terminal sensors in a wireless power supply system.

[0029] The sensing system of this invention constructs independent signal processing channels for pressure sensing and optical sensing, respectively, and converts pressure and photoelectric test data into output curves with unique characteristics through gate-source current and source-drain current, respectively, ensuring that the test results of the two physical quantities can be presented intuitively and independently in different curves. Experimental results prove that the sensing system of this invention can achieve decoupling and accurate observation of pressure and photoelectric data.

[0030] The sensor and sensing system of this invention effectively improve system integration and expand its application scenarios in multiple fields such as smart wearables, human-computer interaction, and environmental monitoring. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a structural block diagram of the pressure and photoelectric integrated sensing system of the present invention.

[0033] Figure 2 This is a block diagram of the antenna structure of the pressure and photoelectric integrated sensing system of the present invention.

[0034] Figure 3 This is a structural diagram of the rectifier of the pressure and photoelectric integrated sensing system of the present invention.

[0035] Figure 4 This is a schematic diagram of the structure of the pressure and photoelectric integrated sensor of the present invention.

[0036] Figure 5 This is a process flow diagram of the pressure and photoelectric integrated sensor of the present invention;

[0037] 100-PDMS material; 101-Silicon substrate; 102-Buffer layer; 103-GaN channel layer; 104-AlN embedding layer; 105-AlGaN barrier; 106-GaN capping layer; 107-Ti / Al / Ni / Au layer; 108-Ni / Au layer.

[0038] Figure 6 This is an efficiency analysis diagram of the rectifier in Embodiment 3 of the present invention.

[0039] Figure 7 This is a graph showing the sensitivity test results of the pressure sensor in Embodiment 4 of the present invention.

[0040] Figure 8 This is the It curve of the sensor's response to ultraviolet light in Embodiment 5 of the present invention.

[0041] Figure 9 This is a graph of the gate-source output current during visible light sensing in Embodiment Six of the present invention. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0043] Example 1:

[0044] This embodiment provides a nonlinear sensitivity microscale pressure-photoelectric sensor based on a suspended AlGaN / GaN heterostructure. By sealing the cavity and transferring two-dimensional materials, it achieves sensing of different pressures and light intensities. In addition, by etching grooves and AlGaN, the turn-on voltage can be raised to 0 threshold, achieving dual decoupling under 0V pressure.

[0045] The structure of the sensor in this embodiment is shown in [reference]. Figure 5 The basic layers from bottom to top include: silicon substrate 101, buffer layer 102, GaN channel 103, AlN insertion layer 104, AlGaN barrier layer 105, and GaN capping layer 106.

[0046] The silicon substrate 101 serves as a support substrate and can be bonded to the AlN layer through bonding or heteroepitaxial processes.

[0047] The buffer layer 102 includes an AlN buffer layer, an AlGaN buffer layer, and a GaN buffer layer. The AlN buffer layer is located on the silicon substrate, and its main function is to alleviate the lattice mismatch and thermal expansion coefficient difference between the silicon substrate and the subsequent GaN layer, reduce defects such as dislocations generated during epitaxial growth, and improve the quality of the subsequent epitaxial layer. The AlGaN buffer layer is located above the AlN buffer layer. By gradually changing the composition of AlGaN (i.e., gradually changing the Al content), the lattice constant can be further adjusted, gradually transitioning to a state more matched with GaN, further reducing dislocation generation and improving the crystal quality of the material. The GaN buffer layer is located above the gradient AlGaN buffer layer. This layer introduces a carbon (C) impurity GaN buffer layer, which can effectively suppress through-type dislocations in the epitaxial layer, improve the electrical properties of the material, and also help improve the quality of the subsequently grown GaN channel layer.

[0048] The GaN channel 103 is located above the buffer layer, which is one of the key regions for the formation of the two-dimensional electron gas (2DEG). Electrons mainly transport in the 2DEG channel formed at the interface between this layer and the AlGaN barrier layer. Its quality directly affects the electrical performance of the device, such as electron mobility and on-resistance.

[0049] The AlN insertion layer 104 is placed on top of the GaN channel layer. The AlN insertion layer can enhance the polarization effect between the AlGaN barrier layer and the GaN channel layer, thereby increasing the concentration of the two-dimensional electron gas and enhancing the performance of the device. At the same time, it can also play a certain role in isolation and improving interface characteristics.

[0050] The AlGaN barrier layer 105 is located above the AlN insertion layer and forms a heterojunction with the GaN channel layer. By utilizing the polarization effect (spontaneous polarization and piezoelectric polarization) between AlGaN and GaN, a high-density two-dimensional electron gas is induced at the interface.

[0051] The GaN capping layer 106 is the top layer of the entire structure. It is usually a thin layer of material, and its main function is to protect the underlying AlGaN barrier layer 105 and other structures from damage by the external environment, such as oxidation and contamination, thereby improving the stability and reliability of the device.

[0052] The source (S) and drain (D) penetrate the GaN capping layer 106 and are connected to the AlGaN barrier layer 105 through ohmic contacts. They are located on both sides of the pressure-sensitive region and are made of stacked metals such as Ti / Al / Ni / Au.

[0053] The gate (G) is located between the source and drain, and forms a Schottky junction through the GaN capping layer 106 and the AlGaN barrier layer 105 to control the conductivity of the 2DEG. Its material is Ni / Au metal.

[0054] Etching is performed between the silicon substrate 101 and the buffer layer 102 on the back of the above-mentioned hierarchical structure until the GaN channel 103 is exposed, forming an opening. Then, the silicon substrate 101 is bonded to the pdms material using bonding technology, thereby forming a closed cavity at the bottom of the GaN channel 103, the opening formed by the silicon substrate 101 and the buffer layer 102, and the top of the pdms material.

[0055] Example 2:

[0056] This embodiment provides a method for fabricating a pressure and photoelectric integrated sensor, see [link to documentation]. Figure 5

[0057] The method includes:

[0058] Step 1: Buffer layer 102 (AlN buffer layer, AlGaN buffer layer, GaN buffer layer), GaN channel 103, AlN insertion layer 104, AlGaN barrier layer 105, and GaN capping layer 106 are sequentially formed on silicon substrate 101.

[0059] Step 2: Etch the edges of GaN capping layer 106, AlGaN barrier layer 105, AlN insertion layer 104 and GaN channel 103 from the top to the middle of GaN channel 103 to isolate the two-dimensional electron gas between the devices.

[0060] Step 3: Etch the source and drain regions of the GaN capping layer 106 to expose the upper surface of the AlGaN barrier layer 105. Sputter Ti / Al / Ni / Au onto the AlGaN barrier layer 105 to form ohmic contacts, and anneal at high temperature (850℃ for 1 min + 500℃ for 10 min) to form the source and drain.

[0061] Step 4: Etch the GaN capping layer 106 and the AlGaN barrier layer 105 in the gate region (approximately 10nm remaining), and sputter Ni / Au onto the AlGaN barrier layer 105 to form the gate.

[0062] Step 5: Photolithography pads (wires), and sputtering Ni / Au after development.

[0063] Step 6: The silicon substrate 101 and buffer layer 102 at the bottom of the photolithography device expose the lower surface of the GaN channel 103, forming an opening.

[0064] Step 7: Bond the sensor to the PDMS using bonding technology to form a sealed cavity.

[0065] Example 3:

[0066] This embodiment provides a wirelessly powered pressure and photoelectric integrated sensing system, such as Figure 1 As shown, the system includes an antenna, a rectifier, and the pressure and photoelectric integrated sensor described in Embodiment 1. The antenna receives wirelessly transmitted energy signals and converts them into electrical signals. The rectifier is connected to the antenna output and filters the output electrical signals to remove noise and interference, converting the AC signal into a DC signal to provide a stable power supply for the sensor. The sensor's gate, source, and source-drain are connected to the rectifier output to form a series circuit. By constructing independent signal processing channels, the pressure and photoelectric test data are converted into output curves with unique characteristics, ensuring that the test results of the two physical quantities can be presented intuitively and independently in different curves, achieving data decoupling and accurate observation.

[0067] This embodiment uses a broadband circularly polarized microstrip monopole with a frequency of 2.4Hz. Monopole antennas have the advantage of wide impedance bandwidth. Microstrip monopole antennas have a simple structure, low profile, small size and low cost, making them a commonly used structure for achieving broadband and circular polarization. They meet the requirements of miniaturization, broadband and circular polarization, solve the problem of coexistence interference in multi-band communication networks, and improve the ability to resist multipath interference and signal attenuation.

[0068] The antenna structure in this embodiment is as follows: Figure 2 As shown, it mainly consists of a radiating unit and a feeding network. When electromagnetic waves (alternating electromagnetic fields) in space are incident on the radiating unit, they induce alternating currents on the conductor surface (or generate alternating electric fields at the dielectric-conductor interface). According to the principle of electromagnetic induction, the radiating unit converts the energy of the electromagnetic waves into high-frequency electrical signals (current or voltage). The feeding network, acting as a transmission line, stably transmits the high-frequency electrical signals output by the radiating unit to the receiving device.

[0069] The rectifier in this embodiment is a microwave rectifier based on microstrip lines and lumped elements. It achieves the conversion of radio frequency to DC through transmission line matching, diode rectification, and capacitor filtering. Efficiency and performance are improved by optimizing the control, and it is used in wireless energy harvesting scenarios (such as RFID and wireless charging).

[0070] Rectifier structure as follows Figure 3 As shown, the RF signal is input from PORT1, passes through a matching network composed of transmission lines and capacitors, and adjusts the signal impedance to match the rectifier circuit with the input source impedance (approximately 50Ω), maximizing signal power transmission and reducing reflections. The transmission lines and capacitors work together to construct a resonant / filtering structure, which, together with a Schottky diode, achieves "RF AC → DC" conversion. The diode utilizes its unidirectional conductivity to cut off the negative half-cycle of the RF signal and conduct during the positive half-cycle. The waveform is smoothed by filtering elements (capacitors and inductors), resulting in a DC output.

[0071] The efficiency analysis of the rectifier in this embodiment is as follows: Figure 6 As shown, the rectifier efficiency (E) under different input power conditions is... ff )as follows:

[0072] P in = -10dBm: Efficiency E ff =40.368%;

[0073] P in = -5dBm: Efficiency E ff =55.007%;

[0074] P in =0.2dBm: Efficiency E ff =50.950%;

[0075] The rectifier efficiency first increases and then decreases with the input power, and there is an optimal power range (such as around -5dBm).

[0076] Example 4: Pressure Sensing

[0077] This embodiment utilizes the pressure and photoelectric integrated sensing system described in Embodiment 3 to sense pressure.

[0078] To verify the characteristics of the system, the pressure was first increased from 0 kPa to 180 kPa. At each pressure setpoint, the pressure was maintained for 600 seconds. The sensitivity test results are as follows: Figure 7 As shown, where Figure 7 (a), (b), and (c) are respectively in V g =-1V, V g =-2V, V g The sensor sensitivity was measured at -3V. The results show that the sensor sensitivity is greatest when the gate voltage is close to or equal to the turn-on voltage.

[0079] Furthermore, by further etching gate grooves or thinning the AlGaN as a whole during the manufacturing process, the threshold of the transistor can be precisely controlled near 0V, enabling pressure and photoelectric sensors to reach maximum sensitivity at 0V. This eliminates the need for a second power supply to power the gate separately, effectively balancing the complexity and sensitivity of powering three-terminal sensors in a wireless power supply system.

[0080] Example 5: Invisible Light Sensing

[0081] In this embodiment, ultraviolet light is used to directly irradiate the GaN thin film of the pressure and photoelectric integrated sensor, and the changes in the It curve are observed at the gate-source output end.

[0082] The It curve of this device's response to ultraviolet light is as follows: Figure 8 As shown in the figure, when exposed to ultraviolet light, the output current of the device increases by 30% to 70% to varying degrees, indicating that the device in this design has a good response to ultraviolet light.

[0083] Example 6: Visible Light Sensing

[0084] In this embodiment, two-dimensional materials MoS2 or WSe2, sensitive to visible light, are transferred onto the gate and source of the pressure and photoelectric integrated sensor described in Embodiment 1. The output current Ig of the gate and source is measured under different light intensities, and the measurement results are as follows: Figure 9 As shown.

[0085] Depend on Figure 9 It can be seen that as the light intensity increases, the gate-source current deflects to varying degrees when approaching the turn-on voltage. When the gate voltage approaches the turn-on voltage, the gate-source output current changes the most with increasing light intensity. This indicates that after transferring the two-dimensional material, the gate-source current responds to visible light, and the response is maximized when the gate voltage approaches the turn-on voltage.

[0086] Example 7: Simultaneous pressure and photoelectric sensing

[0087] This example demonstrates the simultaneous detection of pressure and photoelectric sensors described in Examples 4 and 6.

[0088] During pressure detection, photoelectric signal detection was performed simultaneously to observe whether the introduction of visible light caused changes in the source-leakage current when the pressure value changed. The experimental results remained the same. Figure 7 As shown, the introduction of visible light has almost no effect on the source-drain current; during the photoelectric detection process, pressure was introduced to observe whether it would affect the gate-source current output characteristics, and the experimental results remained as expected. Figure 9 As shown, the application of pressure has no significant effect on the gate-source current. These results indicate that the device exhibits good signal uniformity during pressure and photoelectric signal detection, and no significant cross-interference occurs between the two different output terminals.

[0089] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A pressure and photoelectric integrated sensor, characterized in that, The sensor's basic layers from bottom to top include: silicon substrate (101), buffer layer (102), GaN channel layer (103), AlN insertion layer (104), AlGaN barrier layer (105), and GaN capping layer (106); The source and drain penetrate the GaN capping layer (106) and are connected to the AlGaN barrier layer (105) through ohmic contacts, located on both sides of the pressure-sensitive region; The gate is located between the source and drain, and forms a Schottky contact with the AlGaN barrier layer (105) through the GaN capping layer (106); The silicon substrate (101) and buffer layer (102) form an opening at the bottom of the sensor and are bonded to the pdms material, forming a sealed cavity with the bottom of the GaN channel layer (103).

2. The pressure and photoelectric integrated sensor according to claim 1, characterized in that, The buffer layer (102) includes, from bottom to top, an AlN buffer layer, an AlGaN buffer layer, and a GaN buffer layer.

3. The pressure and photoelectric integrated sensor according to claim 1, characterized in that, The source and drain electrodes are formed by stacking Ti / Al / Ni / Au metals.

4. The pressure and photoelectric integrated sensor according to claim 1, characterized in that, The gate is made of Ni / Au metal.

5. A method for fabricating a pressure and photoelectric integrated sensor, characterized in that, The method includes: Step 1: A buffer layer (102), a GaN channel layer (103), an AlN insertion layer (104), an AlGaN barrier layer (105), and a GaN capping layer (106) are sequentially formed on a silicon substrate (101); Step 2: Etch the edges of the GaN capping layer (106), AlGaN barrier layer (105), AlN insertion layer (104), and GaN channel layer (103) from the top, and stop etching at the middle of the GaN channel layer (103) to isolate the two-dimensional electron gas between the devices; Step 3: Etch the source and drain regions of the GaN capping layer (106) to expose the upper surface of the AlGaN barrier layer (105), sputter metal on the AlGaN barrier layer (105) to form ohmic contacts, and anneal to form the source and drain. Step 4: Etch the GaN capping layer (106) and AlGaN barrier layer (105) in the gate region, and sputter metal on the AlGaN barrier layer (105) to form the gate; Step 5: Photolithography of wires, followed by sputtering of metal material after development; Step 6: The silicon substrate (101) and buffer layer (102) at the bottom of the photolithography device expose the lower surface of the GaN channel (103) to form an opening; Step 7: Bond the sensor to the PDMS using bonding technology to form a sealed cavity.

6. The method for fabricating the pressure and photoelectric integrated sensor according to claim 5, characterized in that, After etching in step 4, a 10nm AlGaN barrier layer (105) thickness is retained.

7. A wirelessly powered pressure and photoelectric integrated sensing system, characterized in that, The system includes: an antenna, a rectifier, and a pressure and photoelectric integrated sensor as described in any one of claims 1-4; The antenna is used to receive wirelessly transmitted energy signals and convert them into electrical signals. The rectifier is connected to the output terminal of the antenna and is used to filter the electrical signals output by the antenna and convert the AC signals into DC signals to provide power to the pressure and photoelectric integrated sensor. The gate and source of the pressure and photoelectric integrated sensor are connected to the output terminal of the rectifier, and the source and drain of the pressure and photoelectric integrated sensor are respectively connected to the output terminal of the rectifier, thus constructing independent signal processing channels for the gate-source current and source-drain current.

8. The wirelessly powered pressure and photoelectric integrated sensing system according to claim 7, characterized in that, The antenna is a broadband circularly polarized microstrip monopole antenna.

9. The wirelessly powered pressure and photoelectric integrated sensing system according to claim 8, characterized in that, The antenna includes a radiating element and a feeding network. The radiating element receives electromagnetic waves and converts the energy of the electromagnetic waves into high-frequency electrical signals. The feeding network transmits the high-frequency electrical signals to the receiving device.

10. The wirelessly powered pressure and photoelectric integrated sensing system according to claim 7, characterized in that, The rectifier is a microwave rectifier based on microstrip lines and lumped elements. It achieves the conversion from radio frequency to DC through transmission line matching, diode rectification, and capacitor filtering.

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