Anti-multipath system and method based on threshold response

Abstract

The invention belongs to the technical field of communication, and particularly relates to an anti-multipath system and method based on threshold response, and the system comprises a pumping driving module, a first antenna, a second antenna, a matching circuit, and a doped transistor. The pumping driving module transmits a radio frequency signal to the outside; an excitation signal provided by the pumping driving module is radiated outwards through the first antenna; the second antenna receives signals which are radiated outwards by the first antenna in a radiation range and comprise various powers generated by a multipath effect, and transmits the signals to the doped transistor through the matching circuit; and the doped transistor enters a conduction working state only under the excitation of a signal meeting a threshold response condition according to a preset threshold condition. The method effectively solves the limitation in the traditional anti-multipath method, not only can utilize the doped transistor to design and formulate the threshold range according to the use requirement, but also has the advantages of no direct current source, high stability, low cost and the like.

Description

Technical Field

[0001] The invention belongs to the field of communication technology, and in particular relates to an anti-multipath system and method based on threshold response. Background Art

[0002] The multipath effect is mainly manifested in that after the electromagnetic wave propagates through different paths, each component field arrives at the receiving end at different times, and the superposition of each other according to their respective phases causes interference, which distorts the original signal or generates errors. For example, if the electromagnetic wave propagates along two different paths, and the lengths of the two paths differ by half a wavelength, then the two signals will cancel each other out when they arrive at the end (the peaks and troughs coincide). The multipath effect has a very serious impact on digital communications, radar optimal detection, etc., and will cause signal fading and phase shift, etc.

[0003] Currently, the commonly used anti-multipath methods mainly include Orthogonal Frequency Division Multiplexing (OFDM) technology and multi-antenna technology.

[0004] Orthogonal frequency division multiplexing (OFDM) technology has significant advantages in resisting multipath fading, which makes it very effective in high-speed data transmission and complex channel conditions. The system structure diagram is shown in the figure. Figure 1 As shown. In the OFDM system, the data stream is divided into multiple subcarriers, each of which has a different frequency and is orthogonal to each other (i.e., perpendicular to each other). This means that the signals of each subcarrier do not interfere with each other in the frequency domain, so even if the signal undergoes multipath propagation, the signal of each subcarrier can still be effectively demodulated back to the original data at the receiving end. In addition, the symbol period of each OFDM subcarrier is relatively long, usually much longer than the typical channel delay spread time. This means that even if the signal experiences time delay changes (multipath effect) caused by different paths during transmission, the receiving end can still eliminate the inter-symbol interference (ICI) caused by time delay through frequency domain equalization. In a complex wireless channel environment, the signal propagates through multiple paths, resulting in multipath effects. Traditional single-carrier modulation (such as QAM or PSK) may suffer from severe inter-symbol interference and performance degradation at the receiving end in this case. OFDM technology can more effectively handle fading and delay in multipath channels by dividing the signal into multiple subcarriers and utilizing the orthogonal properties. In addition, OFDM technology can make full use of spectrum resources, divide the entire frequency band into multiple non-overlapping subcarriers, and each subcarrier can modulate data independently. This spectrum efficiency not only improves the system's data transmission rate, but also enhances the system's resistance to multipath fading, thereby achieving higher system capacity and coverage.

[0005] In summary, OFDM technology effectively improves the system's resistance to multipath fading through its unique subcarrier allocation and frequency domain processing capabilities, making it one of the core technologies widely used in modern digital communication systems. However, OFDM technology is affected by frequency error, phase noise and frequency offset in the time domain, which may lead to uneven bandwidth and partial data loss, and its carrier solution customization is complex and is not suitable for narrowband communication systems.

[0006] Multi-antenna technology is a communication technology that uses multiple transmitting antennas and / or multiple receiving antennas. Its system structure diagram is as follows: Figure 2 As shown. It mainly improves the performance and efficiency of wireless communication systems by increasing the number of antennas and utilizing spatial degrees of freedom. Multi-antenna technology can be applied to the transmitter, the receiver, or both at the same time to achieve different communication enhancement effects. This technology is widely used in digital communication systems, mainly to improve the system's resistance to multipath interference and resist the impact of multipath fading. Through spatial diversity, multiple antennas at the receiving end are used to simultaneously receive multiple versions of the same signal. Due to multipath propagation, the signal reaches the receiving end through different paths, and the signals on these paths may have different phases or amplitudes. The signal versions received by multiple antennas can reduce the signal fading caused by multipath effects after appropriate combination (such as maximum ratio combining). Because the interference on different paths may have different phases, if lucky, they may cancel each other out. In addition, the MIMO system of multi-antenna technology can utilize the spatial degrees of freedom between multiple transmitting antennas and multiple receiving antennas, and significantly improve the signal transmission rate and system capacity through complex signal processing algorithms. In a multipath environment, MIMO technology can not only provide the advantages of spatial diversity, but also use spatial diversity and spatial multiplexing to reduce the loss caused by multipath effects. Through appropriate signal processing and detection algorithms, MIMO systems can effectively restore the original signal, thereby improving the reliability and performance of the system.

[0007] Although multi-antenna technology has significant advantages in improving the performance and efficiency of communication systems, in order to implement multi-antenna technology, multiple antennas need to be deployed at the transmitter and receiver, and equipped with complex signal processing and control hardware. This not only increases the manufacturing cost of the equipment, but also increases the complexity of maintenance and management. In addition, in some applications, such as real-time voice calls or video streaming, multi-antenna systems may introduce additional signal processing delays. This delay may affect the user experience, especially in scenarios that require low-latency responses. In summary, although multi-antenna technology has significant advantages in improving the performance and capacity of wireless communication systems, problems such as high cost, high power consumption, and delay are inevitable during implementation and application. Summary of the invention

[0008] In view of the problems of high cost, high power consumption, delay and the like in the prior art, the present invention proposes an anti-multipath method based on threshold response.

[0009] In order to achieve the above effects, the technical solution adopted by the present invention is as follows:

[0010] An anti-multipath system based on threshold response, comprising:

[0011] Pump drive module: used to transmit radio frequency signals to the outside to stimulate doped transistors;

[0012] The first antenna is connected to the pump driving module, and is used to receive the radio frequency signal emitted by the pump driving module and radiate to the target response area;

[0013] The second antenna is connected to the matching circuit and installed in the area to be responded to, and is used to receive the microwave excitation signal with different powers radiated from the first antenna and feed it into the doped transistor, and the response threshold of the doped transistor is determined by the matching circuit;

[0014] Matching circuit: connected to the second antenna and the doped transistor, it adjusts the S parameters of the target signal frequency by changing the size and combination of capacitors and inductors for the corresponding signal frequency; the higher the matching performance of the circuit, the smaller the signal transmission loss, and the higher the signal receiving efficiency of the device to be responded to;

[0015] Doped transistor: connected to the matching circuit, and only uses it for self-excitation and enters the working state after receiving the microwave excitation signal that meets the threshold response requirement preset by the matching circuit.

[0016] Furthermore, the doped transistor is excited by the RF signal to enter the working state without supplying direct current. The second antenna receives microwave excitation signals of different power levels and feeds them into the doped transistor. After receiving the signal that meets its threshold response, the transistor is in the ground state E 0 Under sufficient energy excitation conditions, the particles transition to the unstable high energy level E h , the particle transitions to the stable E r Energy level, and E r Jump to E 0 energy level, these two processes will radiate external frequencies f a and f r The signal frequency satisfies the relationship:

[0017] f p =f a +f r

[0018] Furthermore, the matching circuit is an LC circuit, according to the formula The resonant frequency of the 2pF capacitor and the 50uH inductor is 15.9MHz. The signal with a frequency of 15.9MHz has the highest passing efficiency and the lowest loss in this matching circuit.

[0019] An anti-multipath method based on threshold response comprises the following steps:

[0020] The pump drive module transmits radio frequency signals to the outside;

[0021] radiating an excitation signal provided by the pump driving module externally through the first antenna;

[0022] The second antenna receives signals radiated by the first antenna within a radiation range and including signals of various power levels generated by a multipath effect, and transmits the signals to the doped transistor through a matching circuit;

[0023] The doped transistor enters a conducting working state only when stimulated by a signal that meets its threshold response condition according to a preset threshold condition.

[0024] Furthermore, the pump driving module transmits a microwave excitation signal with a frequency matching that of the matching circuit to cover the target area to be responded to, and the shape and range of the covered response area are determined by the directional pattern of the first antenna.

[0025] Furthermore, specifically, a reference antenna with known characteristics and an antenna to be tested are used, and a radiation pattern is drawn by measuring the received signal strength at multiple angles and distances. The measured or simulated data are processed and converted into a graph showing the gain or receiving strength changing with angle, wherein the data is smoothed and normalized, and finally a graphics drawing software is used to draw the radiation pattern, which is a two-dimensional polar coordinate graph or a three-dimensional graph.

[0026] Furthermore, the antenna pattern includes the main lobe width, side lobe level and front-to-back ratio, and the pattern is expressed as the product of the unit pattern function and the array factor:

[0027]

[0028] in, is the unit orientation diagram, It is the array factor.

[0029] Furthermore, the target to be responded to with the doped transistor is placed at a certain position in the coverage area of ​​the first antenna, and receives microwave excitation signals of different powers generated by the multipath effect caused by continuous reflection and attenuation of multiple objects at the position.

[0030] The technical effects achieved by the present invention are:

[0031] This system uses the first antenna to transmit a microwave excitation signal to electromagnetically cover the target area to be responded to. Various objects in the target area to be responded to will continuously reflect and attenuate the original microwave excitation signal. The second antenna will then receive electromagnetic signals of different powers, and receive the microwave excitation signal that meets the threshold response requirements determined by the matching circuit through the doped transistor, thereby entering the working state.

[0032] This method effectively solves the limitations of traditional anti-multipath methods. It can not only use the threshold range designed according to the use requirements of doped transistors, but also has the advantages of no DC source, high stability, and low cost.

[0033] The present application utilizes transistor threshold to solve the multipath effect. Interference signals will not cause the transistor to work because their power does not meet the transistor threshold condition.

[0034] The present invention effectively solves the shortcomings of high cost, high power consumption, high delay and insufficient reliability of traditional anti-multipath methods and can be widely used in the fields of wireless communication, semiconductor physics, and electronic technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a system structure diagram of the Orthogonal Frequency Division Multiplexing (OFDM) technology mentioned in the background technology.

[0036] Figure 2 This is a structural diagram of the multi-antenna technology system mentioned in the background technology.

[0037] Figure 3 A schematic diagram of the anti-multipath method based on threshold response provided by the present invention.

[0038] Figure 4 In the embodiment of the present invention, the doped transistor in the energy level system receives the f of the pump driving module. p With the output signal f a relationship. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

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

[0041] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0042] In the description of the present application, it should be noted that the terms "upper", "vertical", "inner", "outer", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the product of the application is usually placed when in use, or the orientation or position relationship commonly understood by those skilled in the art. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0043] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0044] Example 1

[0045] like Figure 3 As shown, a threshold response-based anti-multipath system includes

[0046] Pump drive module: used to transmit radio frequency signals to the outside to stimulate doped transistors;

[0047] The first antenna is connected to the pump driving module, and is used to receive the radio frequency signal emitted by the pump driving module and radiate to the target response area;

[0048] The second antenna is connected to the matching circuit and installed in the area to be responded to, and is used to receive the microwave excitation signal with different powers radiated from the first antenna and feed it into the doped transistor, and the response threshold of the doped transistor is determined by the matching circuit;

[0049] Matching circuit: The corresponding matching circuit is preset according to the frequency of the RF signal emitted by the pump drive module to reduce the signal loss and increase the signal transmission efficiency; the design of the matching circuit follows the basic logic of microwave circuit design, and is connected to the second antenna and the doped transistor. For the corresponding signal frequency, the S parameters of the target signal frequency are adjusted by changing the size and combination of the capacitor and inductor; the higher the matching performance of the circuit, the smaller the signal transmission loss, the higher the signal receiving efficiency of the device to be responded to, and the smaller the power signal can meet the device response requirements, that is, the lower the power threshold; the matching circuit is a well-known content in the field of radio frequency communication, and its specific circuit design is known to those skilled in the art, so it will not be repeated here.

[0050] Doped transistor: connected to the matching circuit, the core component of the threshold response, which only uses it for self-excitation and enters the working state after receiving the microwave excitation signal that meets the threshold response requirements preset by the matching circuit.

[0051] like Figure 4 As shown, the doped transistor is stimulated by the RF signal to enter the working state without supplying DC power. The second antenna receives microwave excitation signals of different power levels and feeds them into the doped transistor. After receiving the signal that meets its threshold response, the transistor is in the ground state E 0 Under sufficient energy excitation conditions, the particles transition to the unstable high energy level E h , and then because of E h Energy level instability, particle transition to stable E r Energy level, and E r Jump to E 0 energy level, these two processes will radiate external frequencies f a and f r The signal frequency satisfies the relationship:

[0052] f p =f a +f r

[0053] The matching circuit is an LC circuit. According to the formula The resonant frequency of the 2pF capacitor and the 50uH inductor is approximately 15.9MHz, that is, the signal with a frequency of 15.9MHz has the highest passing efficiency and the lowest loss in this matching circuit.

[0054] This system uses the first antenna to transmit a microwave excitation signal to electromagnetically cover the target area to be responded to. Various objects in the target area to be responded to will continuously reflect and attenuate the original microwave excitation signal. The second antenna will then receive electromagnetic signals of different powers, and receive the microwave excitation signal that meets the threshold response requirements determined by the matching circuit through the doped transistor, thereby entering the working state.

[0055] The present application utilizes transistor threshold to solve the multipath effect. Interference signals will not cause the transistor to work because their power does not meet the transistor threshold condition.

[0056] The present invention effectively solves the shortcomings of high cost, high power consumption, high delay and insufficient reliability of traditional anti-multipath methods. It has the advantages of no DC power supply, high stability and low cost, and can be widely used in wireless communications, semiconductor physics, electronics technology and other fields.

[0057] Example 2

[0058] An anti-multipath method based on threshold response comprises the following steps:

[0059] The pump drive module transmits radio frequency signals to the outside;

[0060] radiating an excitation signal provided by the pump driving module externally through the first antenna;

[0061] The second antenna receives signals radiated by the first antenna within a radiation range and including signals of various power levels generated by a multipath effect, and transmits the signals to the doped transistor through a matching circuit;

[0062] According to the preset threshold conditions, the doped transistor enters the conducting working state only when stimulated by a signal that meets its threshold response conditions. This effectively solves the shortcomings of traditional anti-multipath methods, such as high cost, high power consumption, high latency, and insufficient reliability.

[0063] The pump driving module transmits a microwave excitation signal with a frequency matching the matching circuit to cover the target area to be responded to, and the shape and range of the covered response area are determined by the directional diagram of the first antenna.

[0064] Specifically, when designing an antenna, software (such as HFSS, CST and other electromagnetic simulation software) will be used to simulate the electromagnetic performance of the antenna. These software can automatically generate theoretical antenna patterns for reference. If an accurate actual antenna pattern is required, an antenna measurement system can be used to obtain the pattern. This usually uses a reference antenna with known characteristics and an antenna to be tested. By measuring the received signal strength at multiple angles and distances, a pattern is drawn, and the measured or simulated data is processed and converted into a graph of gain or received intensity versus angle. After data smoothing and normalization steps, the pattern is finally drawn using graphics drawing software (such as MATLAB, Python's matplotlib library, etc.). The pattern can be drawn as a two-dimensional polar coordinate graph or a three-dimensional graph to more intuitively display the radiation characteristics of the antenna.

[0065] The antenna pattern is a graph that describes the antenna radiation characteristics, including parameters such as main lobe width, side lobe level, and front-to-back ratio. The pattern includes the product of the unit pattern function and the array factor:

[0066]

[0067] in, is the unit orientation diagram, It is the array factor.

[0068] The antenna's directivity pattern is closely related to the antenna's radiation area, and together they describe the antenna's ability to radiate or receive electromagnetic waves in space.

[0069] The radiation area of ​​an antenna refers to the spatial range in which the antenna can effectively radiate or receive electromagnetic waves. This area is usually determined by factors such as the antenna's gain, beam width, main lobe, and side lobe.

[0070] A directivity pattern is a graphical representation of the area that an antenna radiates from. It shows the gain or reception strength of the antenna in different directions and is usually presented as a polar plot.

[0071] The main lobe in the radiation pattern represents the main radiation direction of the antenna, that is, the direction in which the antenna gain is the largest. The center of the radiation area is usually consistent with the direction of the main lobe.

[0072] Beamwidth (usually expressed as half-power beamwidth) is a measure of the width of the main lobe, which determines the coverage of the antenna's radiation area. The narrower the beamwidth, the better the antenna's directivity and the more concentrated the radiation area.

[0073] The side lobes in the radiation pattern represent other radiation areas besides the main lobe. The existence of side lobes may cause interference, especially in communication systems, where the side lobes may receive clutter signals.

[0074] Furthermore, the target to be responded with the doped transistor is placed at a certain position in the coverage area of ​​the first antenna, and receives microwave excitation signals of different powers generated by the multipath effect caused by continuous reflection and attenuation of multiple objects at the location; the target to be responded is the location of the doped transistor, and this location needs to be within the coverage range of the first antenna because the transistor needs to receive the excitation signal emitted by the pump driving module in order to work.

[0075] The continuous reflection and attenuation of objects A and B to generate a large number of interference signals is part of the multipath effect. The multipath effect is a phenomenon in wireless communications. When radio signals encounter obstacles such as buildings, mountains, and trees during propagation, they will be reflected, refracted, or scattered, forming multiple signal paths to reach the receiver. These signal paths may have different propagation delays, phases, amplitudes, and polarization states, and eventually superimpose at the receiver to form a multipath effect.

[0076] Doped transistors are mainly used to receive excitation signals. Interference signals reflected by multipath effects do not meet the threshold conditions of the transistor and will not cause it to enter the working state, while excitation signals that meet the threshold conditions will cause it to enter the working state. The anti-multipath function is achieved by controlling the working threshold of the transistor. The working state refers to the transistor being turned on. In the non-working state, there is no output signal after the signal enters the transistor. Only in the working state will there be an output signal.

[0077] The radiation range of an antenna is related to its own properties. There are omnidirectional antennas and directional antennas. At the same time, within the coverage range of the antenna, the gain at different positions is also different. If there are other objects in the radiation range, it will affect the radiation of the antenna. Therefore, the power of the microwave excitation signal received by the second antenna is related to the radiation range of the first antenna and the distribution of objects within the generation response range.

[0078] The second antenna can receive any frequency signal, but the size is different. The power of the frequency signal that does not match the second antenna itself is very small and will be submerged in the noise and can be ignored. In this design, the second antenna mainly receives the same frequency signal emitted by the pump driver module.

[0079] This method effectively solves the limitations of traditional anti-multipath methods. It can not only use the threshold range designed according to the use requirements of doped transistors, but also has the advantages of no DC source, high stability, and low cost. It can be widely used in wireless communications, semiconductor physics, electronics technology and other fields.

[0080] Example 3

[0081] like Figure 3 As shown, a threshold response-based anti-multipath system includes

[0082] Pump drive module: used to transmit radio frequency signals to the outside to stimulate doped transistors;

[0083] The first antenna is connected to the pump driving module, and is used to receive the radio frequency signal transmitted by the pump driving module and radiate to the generation response target area;

[0084] The second antenna is connected to the matching circuit and installed in the area to be responded to, and is used to receive the microwave excitation signal with different powers radiated from the first antenna and feed it into the doped transistor, and the response threshold of the doped transistor is determined by the matching circuit;

[0085] Matching circuit: The corresponding matching circuit is preset according to the frequency of the RF signal emitted by the pump drive module to reduce the signal loss and increase the signal transmission efficiency; the design of the matching circuit follows the basic logic of microwave circuit design, and is connected to the second antenna and the doped transistor. For the corresponding signal frequency, the S parameters of the target signal frequency are adjusted by changing the size and combination of the capacitor and inductor; the higher the matching performance of the circuit, the smaller the signal transmission loss, the higher the signal receiving efficiency of the device to be responded to, and the smaller the power signal can meet the device response requirements, that is, the lower the power threshold; the matching circuit is a well-known content in the field of radio frequency communication, and its specific circuit design is known to those skilled in the art, so it will not be repeated here.

[0086] Doped transistor: connected to the matching circuit, the core component of the threshold response, which only uses it for self-excitation and enters the working state after receiving the microwave excitation signal that meets the threshold response requirements preset by the matching circuit.

[0087] like Figure 4 As shown, the doped transistor is stimulated by the RF signal to enter the working state without supplying DC power. The second antenna receives microwave excitation signals of different power levels and feeds them into the doped transistor. After receiving the signal that meets its threshold response, the transistor is in the ground state E 0 The particles will jump to the unstable high energy level Eh under sufficient energy excitation conditions, and then due to the instability of the Eh energy level, the particles will jump to the stable Eh r Energy level, and E r Jump to E 0 energy level, these two processes will radiate external frequencies f a and f r The signal frequency satisfies the relationship:

[0088] f p =f a +f r

[0089] The matching circuit is an LC circuit. According to the formula The resonant frequency of the 2pF capacitor and the 50uH inductor is approximately 15.9MHz, that is, the signal with a frequency of 15.9MHz has the highest passing efficiency and the lowest loss in this matching circuit.

[0090] An anti-multipath method based on threshold response comprises the following steps:

[0091] The pump drive module transmits radio frequency signals to the outside;

[0092] radiating an excitation signal provided by the pump driving module externally through the first antenna;

[0093] The second antenna receives signals radiated by the first antenna within a radiation range and including signals of various power levels generated by a multipath effect, and transmits the signals to the doped transistor through a matching circuit;

[0094] According to the preset threshold conditions, the doped transistor enters the conducting working state only when stimulated by a signal that meets its threshold response conditions. This effectively solves the shortcomings of traditional anti-multipath methods, such as high cost, high power consumption, high latency, and insufficient reliability.

[0095] The pump driving module transmits a microwave excitation signal with a frequency matching the matching circuit to cover the target area to be responded to, and the shape and range of the covered response area are determined by the directional diagram of the first antenna.

[0096] Specifically, when designing an antenna, software (such as HFSS, CST and other electromagnetic simulation software) will be used to simulate the electromagnetic performance of the antenna. These software can automatically generate theoretical antenna patterns for reference. If an accurate actual antenna pattern is required, an antenna measurement system can be used to obtain the pattern. This usually uses a reference antenna with known characteristics and an antenna to be tested. By measuring the received signal strength at multiple angles and distances, a pattern is drawn, and the measured or simulated data is processed and converted into a graph of gain or received intensity versus angle. After data smoothing and normalization steps, the pattern is finally drawn using graphics drawing software (such as MATLAB, Python's matplotlib library, etc.). The pattern can be drawn as a two-dimensional polar coordinate graph or a three-dimensional graph to more intuitively display the radiation characteristics of the antenna.

[0097] The antenna pattern is a graph that describes the radiation characteristics of the antenna, including parameters such as the main lobe width, side lobe level, and front-to-back ratio. The pattern consists of the product of the unit pattern function and the array factor:

[0098]

[0099] in, is the unit orientation diagram, It is the array factor.

[0100] The antenna's directivity pattern is closely related to the antenna's radiation area, and together they describe the antenna's ability to radiate or receive electromagnetic waves in space.

[0101] The radiation area of ​​an antenna refers to the spatial range in which the antenna can effectively radiate or receive electromagnetic waves. This area is usually determined by factors such as the antenna's gain, beam width, main lobe, and side lobe.

[0102] A directivity pattern is a graphical representation of the area that an antenna radiates from. It shows the gain or reception strength of the antenna in different directions and is usually presented as a polar plot.

[0103] The main lobe in the radiation pattern represents the main radiation direction of the antenna, that is, the direction in which the antenna gain is the largest. The center of the radiation area is usually consistent with the direction of the main lobe.

[0104] Beamwidth (usually expressed as half-power beamwidth) is a measure of the width of the main lobe, which determines the coverage of the antenna's radiation area. The narrower the beamwidth, the better the antenna's directivity and the more concentrated the radiation area.

[0105] The side lobes in the radiation pattern represent other radiation areas besides the main lobe. The existence of side lobes may cause interference, especially in communication systems, where the side lobes may receive clutter signals.

[0106] The target to be responded with the doped transistor is placed at a certain position in the coverage area of ​​the first antenna, and receives microwave excitation signals of different powers generated by the multipath effect caused by continuous reflection and attenuation of multiple objects at the location; the target to be responded is the location of the doped transistor, and this location needs to be within the coverage range of the first antenna because the transistor needs to receive the excitation signal emitted by the pump driving module in order to work.

[0107] The continuous reflection and attenuation of objects A and B to generate a large number of interference signals is part of the multipath effect. The multipath effect is a phenomenon in wireless communications. When radio signals encounter obstacles such as buildings, mountains, and trees during propagation, they will be reflected, refracted, or scattered, forming multiple signal paths to reach the receiver. These signal paths may have different propagation delays, phases, amplitudes, and polarization states, and eventually superimpose at the receiver to form a multipath effect.

[0108] Doped transistors are mainly used to receive excitation signals. Interference signals reflected by multipath effects do not meet the threshold conditions of the transistor and will not cause it to enter the working state, while excitation signals that meet the threshold conditions will cause it to enter the working state. The anti-multipath function is achieved by controlling the working threshold of the transistor. The working state refers to the transistor being turned on. In the non-working state, there is no output signal after the signal enters the transistor. Only in the working state will there be an output signal.

[0109] The radiation range of an antenna is related to its own properties. There are omnidirectional antennas and directional antennas. At the same time, within the coverage range of the antenna, the gain at different positions is also different. If there are other objects in the radiation range, it will affect the radiation of the antenna. Therefore, the power of the microwave excitation signal received by the second antenna is related to the radiation range of the first antenna and the distribution of objects within the generation response range.

[0110] The second antenna can receive any frequency signal, but the size is different. The power of the frequency signal that does not match the second antenna itself is very small and will be submerged in the noise and can be ignored. In this design, the second antenna mainly receives the same frequency signal emitted by the pump driver module.

[0111] This system uses the first antenna to transmit a microwave excitation signal to electromagnetically cover the target area to be responded to. Various objects in the target area to be responded to will continuously reflect and attenuate the original microwave excitation signal. The second antenna will then receive electromagnetic signals of different powers, and receive the microwave excitation signal that meets the threshold response requirements determined by the matching circuit through the doped transistor, thereby entering the working state.

[0112] This method effectively solves the limitations of traditional anti-multipath methods. It can not only use the threshold range designed according to the use requirements of doped transistors, but also has the advantages of no DC source, high stability, and low cost.

[0113] This application uses transistor thresholds to solve the multipath effect. Interference signals do not cause transistors to work because their power does not meet the transistor threshold conditions. It can be widely used in wireless communications, semiconductor physics, electronics technology and other fields.

[0114] Example 4

[0115] like Figure 3 As shown, it is a schematic diagram of the structure of the anti-multipath system provided by the present invention. It includes a pump driving module, a first antenna, a second antenna, a doped transistor and a matching circuit, wherein the first antenna is connected to the transmitting module and the receiving module, and the second antenna is connected to the doped transistor and the matching circuit. Among them, the role of the pump driving module and the first antenna is to cover the target area to be responded to with electromagnetic waves, and the microwave excitation signal emitted by the pump driving module is radiated into the target area to be responded to through the first antenna. These signals are reflected by various objects in the area and attenuated. At this time, the second antenna will receive microwave excitation signals of different power sizes, and the matching circuit determines the response threshold of the doped transistor. After the doped transistor receives the microwave excitation signal that meets its threshold power requirement, it responds and enters the working state.

[0116] An anti-multipath method comprises the following steps:

[0117] The pump driving module emits electromagnetic waves of a specific frequency to cover the target area to be responded to, and the shape and range of the area are mainly determined by the directional pattern of the first antenna;

[0118] The doped transistor is placed in the target area to be responded to, and receives electromagnetic signals of various powers generated by reflection in the area. When the power of the electromagnetic signal reaches the threshold power designed by the matching circuit to meet the response of the doped transistor, the doped transistor will be turned on and will generate a frequency signal different from that emitted by the pump drive module.

[0119] The anti-multipath method of the present invention has the advantages of no direct current source power supply, high stability, low cost, etc., and can be widely used in the fields of wireless communication, semiconductor physics, and electronic technology.

[0120] The above is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention shall be implemented according to the conventional means in the art unless otherwise specified and limited.

Claims

1. An anti-multipath system based on threshold response, characterized in that: include Pump drive module: used to transmit radio frequency signals to the outside to stimulate doped transistors; The first antenna is connected to the pump driving module, and is used to receive the radio frequency signal emitted by the pump driving module and radiate to the target response area; The second antenna is connected to the matching circuit and installed in the area to be responded to, and is used to receive the microwave excitation signal with different powers radiated from the first antenna and feed it into the doped transistor, and the response threshold of the doped transistor is determined by the matching circuit; Matching circuit: connected to the second antenna and the doped transistor, it adjusts the S parameters of the target signal frequency by changing the size and combination of capacitors and inductors for the corresponding signal frequency; the higher the matching performance of the circuit, the smaller the signal transmission loss, and the higher the signal receiving efficiency of the device to be responded to; Doped transistor: connected to the matching circuit, and only uses it for self-excitation and enters the working state after receiving the microwave excitation signal that meets the threshold response requirement preset by the matching circuit.

2. The anti-multipath system based on threshold response according to claim 1, characterized in that: The doped transistor is stimulated by the RF signal to enter the working state without supplying direct current. The second antenna receives microwave excitation signals of different power and feeds them into the doped transistor. After the transistor receives the signal that meets its threshold response, the particles in the ground state E0 jump to the unstable high energy level E under sufficient energy excitation conditions. h , the particle transitions to the stable E r Energy level, and E r Transition to E0 energy level, these two processes will radiate external frequencies f a and f r The signal frequency satisfies the relationship: f p =f a +f r 。 3. The anti-multipath system based on threshold response according to claim 1, characterized in that: The matching circuit is an LC circuit. According to the formula The resonant frequency of the 2pF capacitor and the 50uH inductor is 15.9MHz. The signal with a frequency of 15.9MHz has the highest passing efficiency and the lowest loss in this matching circuit.

4. A threshold response-based anti-multipath method, characterized in that: The steps include: The pump drive module transmits radio frequency signals to the outside; radiating an excitation signal provided by the pump driving module externally through the first antenna; The second antenna receives signals radiated by the first antenna within a radiation range and including signals of various power levels generated by a multipath effect, and transmits the signals to the doped transistor through a matching circuit; The doped transistor enters a conducting working state only when stimulated by a signal that meets its threshold response condition according to a preset threshold condition.

5. The anti-multipath method based on threshold response according to claim 4, characterized in that: The pump driving module transmits a microwave excitation signal with a frequency matching the matching circuit to cover the target area to be responded to, and the shape and range of the covered response area are determined by the directional diagram of the first antenna.

6. The anti-multipath method based on threshold response according to claim 5, characterized in that: Using a reference antenna with known characteristics and an antenna to be tested, the received signal strength is measured at multiple angles and distances to draw a radiation pattern. The measured or simulated data is processed and converted into a graph of gain or receiving strength versus angle. After data smoothing and normalization steps, the radiation pattern is finally drawn using graphics drawing software. The radiation pattern is a two-dimensional polar coordinate graph or a three-dimensional graph.

7. The anti-multipath method based on threshold response according to claim 6, characterized in that: The antenna pattern includes the main lobe width, side lobe level and front-to-back ratio. The pattern is expressed as the product of the unit pattern function and the array factor: in, is the unit orientation diagram, It is the array factor.

8. The anti-multipath method based on threshold response according to claim 4, characterized in that: The target to be responded with the doped transistor is placed at a certain position in the coverage area of ​​the first antenna, and receives microwave excitation signals of different powers generated by the multipath effect caused by continuous reflection and attenuation of multiple objects at the position.

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