Signal multipath effect simulation system

Abstract

The invention provides a signal multipath effect simulation system, which comprises a radio frequency signal generator, a power divider, a plurality of signal simulation devices, a power combiner and a signal receiver, and is characterized in that each signal simulation device is used for simulating signals with different time delays, and comprises an amplitude controller and a single signal simulator which are in transmission connection; the amplitude controller is used for controlling the amplitude of a signal, the single signal simulator comprises a time delay control panel, a waveguide transmission structure and a radio frequency switch, the waveguide transmission structure comprises a plurality of transmission paths, the lengths of the transmission paths are different, and the radio frequency switch is used for selectively conducting the transmission paths; the radio frequency switch and at least part of the transmission path are arranged on the time delay control board. According to the signal multipath effect simulation system provided by the invention, the system can accurately simulate the multipath effect in a complex channel environment in real time through the coordinated work of the plurality of single channel simulators, and high-precision channel characteristic simulation is provided.

Description

Technical Field

[0001] The invention belongs to the technical field of signal transmission, and more specifically, relates to a signal multipath effect simulation system. Background Art

[0002] In mobile communication systems, the multipath propagation effect caused by complex electromagnetic environments will significantly affect the communication quality, especially in high frequency bands (such as millimeter wave bands) and strong reflection environments (such as cabins and spacecraft metal cavities). In scenarios where metal is the main reflection surface, non-line-of-sight propagation (NLOS) accounts for almost more than 90%, and the delay-power distribution of multipath signals presents a dense superposition characteristic, which puts higher requirements on the establishment and verification of channel models. Traditional channel modeling methods rely on a large amount of measurement data from actual scenarios to generate statistical models, and then design communication system solutions based on model parameters. However, physical channel measurement consumes a lot of resources and is difficult to verify repeatedly in dynamic scenarios. It has the problems of high cost, lengthy cycle and difficulty in dynamically reconstructing scenarios. Channel simulators have become a key tool to replace actual measurements, but existing solutions have significant limitations in delay control accuracy, scalability and hardware cost control in millimeter wave bands, especially in meeting key requirements such as adjustable delay of multipath signal distribution and multipath superposition.

[0003] The core challenge of channel multipath effect simulation is to reproduce the delay spread characteristics with high precision, that is, the time, amplitude and spatial arrival differences of the simulated signal after propagation through different paths. Especially in high frequency bands (such as 60 GHz) and strong metal reflection scenarios, the superposition characteristics of multipath signals are significant, and the propagation path is significantly constrained by the physical structure (such as medium diffraction and metal interface reflection). Existing simulation technologies are mostly based on digital domain algorithms (such as FPGA or ASIC) to simulate the multipath superposition effect at the baseband end. Its output depends on idealized mathematical models and cannot truly reflect the actual propagation behavior of RF signals in physical links. It is especially difficult to simulate the dynamic characteristics of path-related delays caused by structural limitations in metal cavities. Therefore, how to achieve dynamic, adjustable and precise control of physical-level delay spread through hardware devices is a difficulty that needs to be solved in the field of channel simulation. Summary of the invention

[0004] The purpose of the embodiment of the present invention is to provide a signal multipath effect simulation system to solve the technical problems of limited real-time performance and simulation accuracy of digital signal simulation systems in the prior art.

[0005] To achieve the above object, the technical solution adopted by the present invention is: to provide a signal multipath effect simulation system, comprising: A radio frequency signal generator, used for sending a radio frequency signal; A power divider, used for dividing the radio frequency signal into multiple signals; A plurality of signal simulation devices, wherein multiple signals are respectively input to the corresponding signal simulation devices, each of which is used to simulate signals with different delays, wherein the signal simulation device comprises an amplitude controller and a single signal simulator of a transmission connection, wherein the amplitude controller is used to control the amplitude of the signal, wherein the single signal simulator comprises a delay control board, a waveguide transmission structure and a radio frequency switch, wherein the waveguide transmission structure comprises a plurality of transmission paths, wherein the lengths of the transmission paths are different, wherein the radio frequency switch is used to selectively conduct the transmission paths, wherein the radio frequency switch and at least a part of the transmission paths are both arranged on the delay control board; A power synthesizer, connected to the plurality of signal simulation devices for synthesizing output signals of the plurality of signal simulation devices; A signal receiver is used to convert the composite signal into a time-delay power distribution.

[0006] Optionally, the waveguide transmission structure includes multiple sections of grounded coplanar waveguides, two adjacent sections of the grounded coplanar waveguides are connected through the radio frequency switch, and at least two sections of the grounded coplanar waveguides are arranged in parallel.

[0007] Optionally, the waveguide transmission structure includes a plurality of first transmission units connected in series, the first transmission unit includes a first grounded coplanar waveguide and a second grounded coplanar waveguide connected in parallel, and the first end of the first grounded coplanar waveguide is connected to the first end of the second grounded coplanar waveguide through the RF switch, and the second end of the first grounded coplanar waveguide is connected to the second end of the second grounded coplanar waveguide through the RF switch, so that the first grounded coplanar waveguide and the second grounded coplanar waveguide are selectively conductive, and the lengths of the first grounded coplanar waveguide and the second grounded coplanar waveguide are different.

[0008] Optionally, two adjacent first transmission units are connected via a transmission connection waveguide, and two ends of the transmission connection waveguide are respectively connected to the radio frequency switches of the two first transmission units.

[0009] Optionally, in each of the first transmission units, a length difference between the second grounded coplanar waveguide and the first grounded coplanar waveguide is a geometric progression.

[0010] Optionally, the waveguide transmission structure also includes a plurality of second transmission units connected in series, the first transmission unit and the second transmission unit are connected in series, the second transmission unit includes a third grounded coplanar waveguide, two fourth grounded coplanar waveguides and a rectangular waveguide, the two ends of the third grounded coplanar waveguide are respectively connected to the first ends of the two fourth grounded coplanar waveguides through the RF switch, the second ends of the two fourth grounded coplanar waveguides are coupled to the rectangular waveguide, so that the rectangular waveguide and the third grounded coplanar waveguide are selectively conductive, and the transmission channels of the rectangular waveguides have different lengths.

[0011] Optionally, the rectangular waveguide has a hollow transmission channel inside, both ends of the transmission channel have coupling windows, the two coupling windows are located on the same side wall of the rectangular waveguide, and the two coupling windows are respectively opposite to the second ends of the two fourth grounded coplanar waveguides.

[0012] Optionally, the rectangular waveguide includes a first metal plate and a second metal plate, the first metal plate is provided with a first groove, the second metal plate is provided with a second groove, the first metal plate and the second metal plate are fixedly connected by fastening screws, and the first groove and the second groove are arranged opposite to each other to form the transmission channel.

[0013] Optionally, the rectangular waveguide is vertically arranged on the delay control board, and each of the rectangular waveguides is arranged in sequence along the thickness direction thereof, and a reinforcement plate is arranged at a position away from the delay control board for the plurality of rectangular waveguides, and the reinforcement plate is fixed to the plurality of rectangular waveguides.

[0014] Optionally, the single signal simulator also includes a radar chip, a signal transmitting end and a signal receiving end are provided on the delay control board, the waveguide transmission structure is located between the signal transmitting end and the signal receiving end, and the radar chip is also connected between the signal transmitting end and the signal transmitting end.

[0015] The beneficial effect of the signal multipath effect simulation system provided by the present invention is that: compared with the prior art, the signal multipath effect simulation system of the present invention includes a radio frequency signal generator, a power divider, multiple signal simulation devices, a power synthesizer and a signal receiver, each signal simulation device is used to simulate signals with different delays, each signal simulation device includes an amplitude controller and a single signal simulator, and the single signal simulator includes a delay control board, a waveguide transmission structure composed of multiple transmission paths, and a radio frequency switch, and the lengths of each transmission path are different. After the power divider decomposes the signal into multiple signals, each signal is attenuated to a different amplitude by the amplitude controller, and then a corresponding delay is formed by a single signal simulator. Moreover, the single signal simulator can switch different transmission paths through the radio frequency switch, so different delays can be formed accordingly. The power synthesizer linearly superimposes the multiple signals that have been delayed, and obtains the complete delay power distribution characteristics through the signal receiver, thereby reproducing the delay power distribution law of the simulated real environment. Through the coordinated work of multiple single channel simulators, the system can simulate the multipath effect in a complex channel environment in real time and accurately, and provide high-precision channel characteristic simulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A schematic diagram of the structure of a signal multipath effect simulation system provided by an embodiment of the present invention; Figure 2 A schematic diagram of the structure of a delay control board provided in an embodiment of the present invention; Figure 3 A schematic diagram of the structure of a single signal simulator provided by an embodiment of the present invention; Figure 4 A schematic diagram of the structure of a switch control board provided in an embodiment of the present invention.

[0018] Among them, the reference numerals in the figure are: 10-delay control board; 11-signal transmitting end; 12-signal receiving end; 20-waveguide transmission structure; 21-first transmission unit; 211-first grounded coplanar waveguide; 212-second grounded coplanar waveguide; 22-second transmission unit; 221-third grounded coplanar waveguide; 222-fourth grounded coplanar waveguide; 2221-coupling part; 223-rectangular waveguide; 2231-transmission channel; 2232-fastening screw; 23-transmission connecting waveguide; 30-RF switch; 40-reinforcement plate; 50-switch control board; 51-control unit. DETAILED DESCRIPTION

[0019] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0020] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0021] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention 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 operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0022] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0023] At present, channel simulation technology is mainly divided into two categories: digital signal processing solutions and RF hardware reconstruction solutions. Digital signal processing solutions combine mathematical models with channel theory and use algorithms to accurately simulate factors such as delay, frequency offset, and Doppler effect in wireless channels. It has become the mainstream simulation technology. Its advantage lies in its strong flexibility and the ability to finely control channel characteristics in software, making it suitable for simulation of various complex wireless environments. Although digital signal processing solutions can provide high accuracy and flexibility, their real-time simulation and physical signal reconstruction capabilities are relatively limited.

[0024] In contrast, the RF hardware reconstruction solution uses actual hardware devices to dynamically adjust the signal's delay, frequency and other channel characteristics, which can more realistically reproduce the multipath effect and other physical characteristics in complex channels. This method can simulate wireless signal propagation in high-frequency, large-bandwidth environments, and is suitable for scenarios that require extremely high signal authenticity and real-time response, such as 5G communications and satellite communications.

[0025] The current channel simulation technology has the following defects: 1. Lack of true reconstruction of physical signals: Current channel simulation technologies mostly rely on digital signal processing and mathematical models. Although they can simulate time delays and frequency changes, they are difficult to fully restore the physical transmission characteristics of signals in real environments, especially in terms of multipath effects and nonlinear signal processing.

[0026] 2. Limitations of real-time performance and accuracy: Digital signal simulation systems usually require a lot of calculations to simulate channel changes. As the signal complexity increases, real-time performance and accuracy may be limited, especially in high-dynamic channel testing, where digital models may not be able to provide sufficiently fast response and accurate simulation.

[0027] 3. Large size and poor versatility: Traditional channel emulators are usually large, inflexible, and highly specialized, making it difficult to meet the requirements of portability and adaptability to multiple scenarios. This limits the application of the device in actual scenarios.

[0028] 4. High cost and maintenance burden: Many channel simulation systems are expensive, especially those that rely on high-power signal sources and complex measurement modules. Not only are they expensive to purchase, but they are also relatively onerous to maintain and use, increasing the economic pressure on R&D and testing.

[0029] 5. Limited simulation capabilities in high-frequency bands: In high-frequency applications (such as millimeter wave or higher frequency bands), existing digital simulation equipment may find it difficult to accurately simulate the attenuation and delay distribution of signals, limiting their application in modern communications and complex environment testing.

[0030] Compared with the digital channel simulation scheme in the related art, the present application has more realistic physical signal simulation capability, lower cost and smaller volume, and has greater advantages in simulation accuracy of high frequency bands and multipath effects.

[0031] The multipath effect refers to the phenomenon that in a wireless channel, the transmitted signal reaches the receiving end through multiple propagation paths. Due to the different propagation distances and environments of these paths, the signal will experience different paths when reaching the receiving end, resulting in different delays, phases and amplitudes, which will lead to signal superposition, interference or attenuation. The multipath effect can cause problems such as signal fading, delay spread and frequency selective fading, and is one of the main factors affecting wireless communication performance.

[0032] The signal multipath effect simulation system provided by the embodiment of the present invention is now described. In a complex environment, after a signal is sent from a transmitter, it will not propagate along a single propagation path, but will usually propagate along multiple paths to a receiver. During the propagation process, the signal will have characteristics such as amplitude attenuation, phase change, and time delay. In order to better study the characteristics of signal multipath transmission, the present invention proposes a signal multipath effect simulation system, which simulates the characteristics of amplitude attenuation, time delay (delay), etc. of a signal from a transmitter to a receiver through multiple propagation paths.

[0033] Please also read Figure 1 and Figure 2 , the signal multipath effect simulation system includes: A radio frequency signal generator, used for sending a radio frequency signal; A power divider is used to divide the radio frequency signal into multiple signals; Multiple signal simulation devices, multiple signals are respectively input to corresponding signal simulation devices, each signal simulation device is used to simulate signals with different delays, the signal simulation device includes an amplitude controller and a single signal simulator of a transmission connection, the amplitude controller is used to control the amplitude of the signal, the single signal simulator includes a delay control board 10, a waveguide transmission structure 20 and a radio frequency switch 30, the waveguide transmission structure 20 includes multiple transmission paths, each transmission path has a different length, the radio frequency switch 30 is used to selectively conduct each transmission path, and the radio frequency switch 30 and at least part of the transmission path are both arranged on the delay control board 10; A power synthesizer, connected to the plurality of signal simulation devices for synthesizing output signals of the plurality of signal simulation devices; A signal receiver is used to convert the composite signal into a time-delay power distribution.

[0034] RF signal generators are used to generate and transmit RF signals at various frequencies. RF signals can be electromagnetic waves, such as frequency modulated continuous waves. A power splitter, also known as a power divider, is a device that divides the energy of an input signal into two or more equal or unequal energy outputs. When a power splitter divides an RF signal into multiple signals, the multiple signals can be the same signal or different signals.

[0035] The signal simulation device is used to simulate the propagation characteristics of a signal in a certain propagation path (a propagation path corresponding to a certain time delay), or to simulate the propagation characteristics of a signal in a similar propagation path (a propagation path corresponding to a certain time delay). Multiple signal simulation devices can simulate the propagation characteristics of all or nearly all propagation paths. The signal simulation device includes an amplitude controller of a transmission connection and a single signal simulator. The transmission connection means that the signal can be transmitted between the two. For example, the amplitude controller can be connected to the single signal simulator in series. The amplitude controller is used to control the amplitude of the input signal, and the amplitude of the input signal is controlled according to the attenuation amplitude of the signal in each actual propagation path. In this way, the amplitude controller can simulate the attenuation of the amplitude of the signal after passing through the propagation path, and the single signal simulator can simulate the delay of the signal after passing through one of the propagation paths. The single signal simulator includes a delay control board 10, a waveguide transmission structure 20 and a radio frequency switch 30, and the waveguide transmission structure 20 and the radio frequency switch 30 are both arranged on the delay control board 10. The delay control board 10 can be understood as a circuit board. The waveguide transmission structure 20 is used to simulate the delay of the signal during transmission. The waveguide transmission structure 20 includes multiple transmission paths. The lengths of the transmission paths are different, and the time required for the signal to pass through each transmission path is also different. Therefore, in each different single signal simulator, a transmission path can correspond to the simulation of the delay of a propagation path. The RF switch 30 is used to selectively conduct each transmission path, which means that the RF switch 30 can control the waveguide transmission structure 20 so that each transmission path conducts different transmission paths in different states to simulate the delay of the corresponding propagation path.

[0036] The power synthesizer is used to synthesize the output signals of multiple signal simulation devices. The synthesized signal is called a synthesized signal. The signal receiver is used to convert the above-mentioned synthesized signal into a delay power distribution. The delay power distribution refers to the power corresponding to each delay. It can also be understood as a distribution diagram with the horizontal axis being the delay and the vertical axis being the power corresponding to the delay. The delay power distribution facilitates the analysis of wireless signals.

[0037] The signal multipath effect simulation system works as follows: the RF signal generator transmits the RF signal, and the signal is decomposed into multiple signals through the power divider. Each signal is transmitted to a different signal simulation device. In the signal simulation device, the amplitude of the signal is changed by the amplitude controller to simulate the amplitude attenuation of the signal during transmission. Then, a single signal simulator is used to simulate the time delay of the signal during transmission. Each single signal simulator can simulate the propagation path corresponding to different delays by changing its transmission path. Accordingly, multiple signal simulation devices respectively simulate signals of different propagation paths.

[0038] The signal multipath effect simulation system in the above embodiment includes a radio frequency signal generator, a power divider, a plurality of signal simulation devices, a power synthesizer and a signal receiver. Each signal simulation device is used to simulate signals with different delays. Each signal simulation device includes an amplitude controller and a single signal simulator. The single signal simulator includes a delay control board 10, a waveguide transmission structure 20 composed of a plurality of transmission paths and a radio frequency switch 30. The lengths of the transmission paths are different. After the power divider decomposes the signal into multiple signals, each signal is attenuated to a different amplitude by the amplitude controller, and then a corresponding delay is formed by a single signal simulator. Moreover, the single signal simulator can switch different transmission paths through the radio frequency switch 30, so different delays can be formed accordingly. The power synthesizer linearly superimposes the multipath signals after the delay, and obtains the complete delay power distribution characteristics through the signal receiver, thereby reproducing the delay power distribution law of the simulated real environment. Through the coordinated work of multiple single channel simulators, the system can simulate the multipath effect in a complex channel environment in real time and accurately, and provide high-precision channel characteristic simulation.

[0039] In some embodiments of the present invention, see Figure 2 , the waveguide transmission structure 20 includes multiple sections of grounded coplanar waveguides, two adjacent sections of grounded coplanar waveguides are connected by a radio frequency switch 30, and at least two sections of grounded coplanar waveguides are arranged in parallel. The grounded coplanar waveguide is a microwave waveguide transmission structure commonly used in high-frequency circuits, generally consisting of a central signal line, a symmetrical ground plane, and metallized vias on both sides. The signal propagates along the central signal line, and the electromagnetic energy is effectively confined between the central signal line and the ground plane. The grounded coplanar waveguide has low radiation loss, good impedance matching and superior high-frequency performance, and is widely used in millimeter-wave radio frequency circuits, and is suitable for high-density, high-performance communication systems. Specifically, in this embodiment, the grounded coplanar waveguide includes a central signal line and two grounding wires located on both sides of the central signal line, the central signal line and the grounding wire are both located on the front of the delay control board 10, and the two grounding wires are connected to the metal ground on the back of the delay control board 10 through metal vias. At least two sections of grounded coplanar waveguides are arranged in parallel, so that one of the grounded coplanar waveguides can be selected and controlled to be turned on through the radio frequency switch 30.

[0040] Optionally, a first end of one grounded coplanar waveguide is connected to a first end of another grounded coplanar waveguide through a radio frequency switch 30 , and a second end of one grounded coplanar waveguide is connected to a second end of another grounded coplanar waveguide through a radio frequency switch 30 .

[0041] In some embodiments of the present invention, see Figure 2 The waveguide transmission structure 20 includes a plurality of first transmission units 21 connected in series, the first transmission unit 21 includes a first grounded coplanar waveguide 211 and a second grounded coplanar waveguide 212 connected in parallel, and a first end of the first grounded coplanar waveguide 211 is connected to a first end of the second grounded coplanar waveguide 212 via a radio frequency switch 30, and a second end of the first grounded coplanar waveguide 211 is connected to a second end of the second grounded coplanar waveguide 212 via a radio frequency switch 30, so that the first grounded coplanar waveguide 211 and the second grounded coplanar waveguide 212 are selectively turned on, and the lengths of the first grounded coplanar waveguide 211 and the second grounded coplanar waveguide 212 are different. The RF switch 30 can make the signal pass through the first ground coplanar waveguide 211 or the second ground coplanar waveguide 212. Since the lengths of the first ground coplanar waveguide 211 and the second ground coplanar waveguide 212 are different, the transmission time of the signal in the first ground coplanar waveguide 211 and the second ground coplanar waveguide 212 is different. By selecting different ground coplanar waveguides, the delay signal simulated by the single signal simulator can be changed. When two adjacent first transmission units 21 are connected in series, the RF switches 30 of the two first transmission units 21 are connected to each other.

[0042] By setting a plurality of first transmission units 21, a corresponding grounded coplanar waveguide is selected in each first transmission unit 21 to conduct, so as to facilitate step-by-step delay control and achieve as many delays as possible when the number of grounded coplanar waveguides is small. Such a design also makes the signal delay adjustment highly accurate and can adapt to the stable transmission of high-frequency signals.

[0043] In some embodiments, see Figure 2 , two adjacent first transmission units 21 are connected through a transmission connection waveguide 23, and both ends of the transmission connection waveguide 23 are respectively connected to the RF switches 30 of the two first transmission units 21. The transmission connection waveguide 23 connects the two first transmission units 21, and the transmission connection waveguide 23 is also a grounded coplanar waveguide. When the two grounded coplanar waveguides are turned on by the RF switch 30, the central signal lines of the two grounded coplanar waveguides are turned on, and the connection lines of the two grounded coplanar waveguides are turned on accordingly.

[0044] By providing the transmission connection waveguide 23 , multiple first transmission units 21 can be arranged more conveniently, thereby reducing the influence of mutual coupling between adjacent first transmission units 21 .

[0045] In some embodiments of the present invention, see Figure 2 In each first transmission unit 21, the length difference between the second ground coplanar waveguide 212 and the first ground coplanar waveguide 211 is a geometric progression. The length difference between each second ground coplanar waveguide 212 and the corresponding first ground coplanar waveguide 211 is ,in, p is a constant, n For the convenience of description, the length difference between the second grounded coplanar waveguide 212 and the first grounded coplanar waveguide 211 of the first transmission unit 21 may be referred to as the transmission distance difference of the first transmission unit 21 .

[0046] By setting the transmission distance difference of the first transmission unit 21 as a geometric progression, it is easier for a single signal simulator to implement step-by-step delay adjustment.

[0047] In some embodiments, see Figure 2 Through full-wave simulation analysis, the electromagnetic wave transmission delay of the grounded coplanar waveguide is approximately 20 cm / ns. The number of first transmission units 21 is 3, and the three first transmission units 21 are named first transmission unit 21 No. 1, first transmission unit 21 No. 2, and first transmission unit 21 No. 3 from left to right. The transmission distance difference of first transmission unit 21 No. 1 is 5 cm, the transmission distance difference of first transmission unit 21 No. 2 is 10 cm, and the transmission distance difference of first transmission unit 21 No. 3 is 20 cm. In this way, switching between the first ground coplanar waveguide 211 and the second ground coplanar waveguide 212 in the first transmission unit 21 No. 1 can generate a delay of 0.25 ns; switching between the first ground coplanar waveguide 211 and the second ground coplanar waveguide 212 in the first transmission unit 21 No. 2 can generate a delay of 0.5 ns; switching between the first ground coplanar waveguide 211 and the second ground coplanar waveguide 212 in the first transmission unit 21 No. 3 can generate a delay of 1 ns.

[0048] In some embodiments of the present invention, see Figure 3The waveguide transmission structure 20 also includes a plurality of second transmission units 22 connected in series, the first transmission unit 21 and the second transmission unit 22 are connected in series, the second transmission unit 22 includes a third grounded coplanar waveguide 221, two fourth grounded coplanar waveguides 222 and a rectangular waveguide 223, the two ends of the third grounded coplanar waveguide 221 are respectively connected to the first ends of the two fourth grounded coplanar waveguides 222 through the RF switch 30, and the second ends of the two fourth grounded coplanar waveguides 222 are coupled and connected to the rectangular waveguide 223, so that the rectangular waveguide 223 and the third grounded coplanar waveguide 221 are selectively connected, and the lengths of the transmission channels 2231 of each rectangular waveguide 223 are different. The number of the first transmission unit 21 and the second transmission unit 22 are both multiple, and the first transmission unit 21 and the second transmission unit 22 are connected in series, which can be the following situations: multiple first transmission units 21 are connected in series in sequence, multiple second transmission units 22 are connected in series in sequence, and then the two are connected in series; the first transmission unit 21 and the second transmission unit 22 can also be connected in series alternately. The RF switch 30 is set to connect the rectangular waveguide 223 in parallel with the fourth grounded coplanar waveguide 222 and the third grounded coplanar waveguide 221. When the RF switch 30 turns on the rectangular waveguide 223, the two fourth grounded coplanar waveguides 222 and the rectangular waveguide 223 serve as part of the transmission path. When the RF switch 30 turns on the third grounded coplanar waveguide 221, the third grounded coplanar waveguide 221 serves as part of the transmission path.

[0049] Since the area of ​​the delay control board 10 is limited and the length of the grounded coplanar waveguide is also limited, it is difficult to expand the delay adjustment range of a single signal simulator under the limited area. Therefore, by coupling the grounded coplanar waveguide with the rectangular waveguide 223, the rectangular waveguide 223 is used as a part of the transmission path to increase the delay adjustment range of the single signal simulator. Moreover, the lengths of the transmission channels 2231 of the rectangular waveguides 223 are different, which can further increase the delay adjustment range of the single signal simulator.

[0050] In some embodiments, see Figure 3Through full-wave simulation analysis, it is found that the electromagnetic wave transmission delay of the rectangular waveguide 223 is approximately 20 cm / ns. The number of the second transmission units 22 is 4, and the three second transmission units 22 are named No. 1 second transmission unit 22, No. 2 second transmission unit 22, No. 3 second transmission unit 22 and No. 4 second transmission unit 22 from right to left. For the convenience of description, the sum of the lengths of the transmission channels 2231 of the two fourth grounded coplanar waveguides 222 and the rectangular waveguide 223 minus the length of the third grounded coplanar waveguide 221 can be called the transmission distance difference of the second transmission unit 22. The transmission distance difference of the No. 1 second transmission unit 22 is 40cm, the transmission distance difference of the No. 2 first transmission unit 21 is 80cm, the transmission distance difference of the No. 3 first transmission unit 21 is 160cm, and the transmission distance difference of the No. 4 first transmission unit 21 is 320cm. Thus, switching between the two transmission paths in the second transmission unit 22 No. 1 may generate a delay of 2 ns; switching between the two transmission paths in the second transmission unit 22 No. 2 may generate a delay of 4 ns; switching between the two transmission paths in the second transmission unit 22 No. 3 may generate a delay of 8 ns; and switching between the two transmission paths in the second transmission unit 22 No. 4 may generate a delay of 16 ns.

[0051] Through the coordinated work between the three first transmission units 21 and the four second transmission units 22, and the cascaded combination of 14 RF switches 30, it is intended to achieve delay control with an accuracy of 0.25 ns in the range of 0 to 31.75 ns. The function of the RF switch 30 is to flexibly switch the signal path to ensure that the signal is dynamically switched between different paths as needed, thereby achieving precise signal delay control.

[0052] In some embodiments, the minimum frequency of the signal multipath effect simulation system is 60 GHz, the maximum frequency is 64 GHz, the operating bandwidth is 4 GHz, and the single signal delay control range is 0~31.75 ns, with a step of 0.25 ns.

[0053] In some embodiments of the present invention, see Figure 4 , Figure 4 is a structural diagram of a switch control board 50 , each RF switch 30 is controlled by the switch control board 50 , thereby realizing control and switching of a transmission path in a single signal simulator.

[0054] In some embodiments, the switch control board 50 may be a GPIO control board, and the control unit 51 on the switch control board 50 is an STM32 MCU.

[0055] In some embodiments, the RF switch 30 is an ADRF5032 chip.

[0056] In some embodiments of the present invention, see Figure 3 The rectangular waveguide 223 has a hollow transmission channel 2231 inside. Both ends of the transmission channel 2231 have coupling windows. The two coupling windows are located on the same side wall of the rectangular waveguide 223. The two coupling windows are respectively opposite to the second ends of the two fourth grounded coplanar waveguides 222. The rectangular waveguide 223 is a metal structure. The inner wall of the transmission channel 2231 formed inside it is equivalent to a metal shell. Signals can be transmitted in the transmission channel 2231. The rectangular waveguide 223 has six different side walls. The two coupling windows are located on the same side wall of the rectangular waveguide 223. One coupling window is coupled to the second end of a fourth grounded coplanar waveguide 222. Figure 3 , both coupling windows are located at the bottom wall of the rectangular waveguide 223. Among the two coupling windows, one coupling window is a signal input window, and the other window is a signal output window.

[0057] The two coupling windows are arranged on the same side wall of the rectangular waveguide 223, and the second ends of the two fourth grounded coplanar waveguides 222 are also located on the same surface (the front side of the delay control board 10), so that the two ends of the transmission channel 2231 of the rectangular waveguide 223 can be closely arranged with the second ends of the two fourth grounded coplanar waveguides 222, respectively, to achieve coupled transmission between the rectangular waveguide 223 and the fourth grounded coplanar waveguide 222.

[0058] In some embodiments, see Figure 3 The transmission channel 2231 is arranged in an arch shape, and the length of the transmission channel 2231 can be increased in a limited area.

[0059] In some embodiments, see Figure 2 and Figure 3 The fourth grounded coplanar waveguide 222 has a coupling part 2221 made of metal at one end away from the RF switch 30. The coupling part 2221 is located on the front side of the delay control board 10. A hollow hole is opened at the center of the coupling part 2221. The coupling window of the rectangular waveguide 223 is arranged opposite to the hollow hole. The grounding line of the fourth grounded coplanar waveguide 222 is connected to the coupling part 2221. The center line of the fourth grounded coplanar waveguide 222 extends to a position close to the coupling part 2221 and is spaced apart from the coupling part 2221. An extension line and a feeding part are arranged on the back side of the delay control board 10. One end of the extension line is connected to one end of the center line of the fourth grounded coplanar waveguide 222 through a metal via, and the other end of the extension line is connected to the feeding part. The feeding part is arranged opposite to the hollow hole and is used to realize coupling feeding of the fourth grounded coplanar waveguide 222 and the rectangular waveguide 223.

[0060] In some embodiments of the present invention, see Figure 3The rectangular waveguide 223 includes a first metal plate and a second metal plate. The first metal plate is provided with a first groove, and the second metal plate is provided with a second groove. The first metal plate and the second metal plate are fixedly connected by a fastening screw 2232, and the first groove and the second groove are arranged opposite to each other to form a transmission channel 2231. The extension direction of the first groove and the second groove is the same as the extension direction of the transmission channel 2231. The side of the first metal plate with the first groove and the side of the second metal plate with the second groove are closely attached to each other, so that the first groove and the second groove together constitute the transmission channel 2231.

[0061] By dividing the rectangular waveguide 223 into a first metal plate and a second metal plate, it is more convenient to process the transmission channel 2231. Compared with hollowing out a whole metal plate to form a transmission channel, the process of processing grooves on two metal plates is simpler and more costly. By fastening the first metal plate and the second metal plate together by tightening the screws 2232, not only can the two metal plates be fixed, but also the two metal plates can be closely attached to each other, and the transmission channel 2231 is a channel with a complete structure, so as not to affect the transmission of the signal in the transmission channel 2231.

[0062] In some embodiments, multiple fastening screws 2232 are distributed in sequence along the extension direction of the transmission channel 2231, and the transmission channel 2231 has fastening screws 2232 on both sides of its width direction, so as to reduce the gap between the first metal plate and the second metal plate and reduce the gap on the inner wall of the transmission channel 2231.

[0063] In some embodiments of the present invention, see Figure 3 , the rectangular waveguide 223 is vertically arranged on the delay control board 10, and each rectangular waveguide 223 is sequentially spaced along the thickness direction thereof, and a reinforcing plate 40 is arranged at a position away from the delay control board 10 of the plurality of rectangular waveguides 223, and the reinforcing plate 40 is fixed to the plurality of rectangular waveguides 223. The rectangular waveguide 223 is vertically arranged on the delay control board 10, and it can be understood that the thickness direction of the rectangular waveguide 223 is perpendicular to the thickness direction of the delay control board 10, which is equivalent to the rectangular waveguide 223 "standing" on the delay control board 10. For the convenience of explanation, the time delay control board 10 is located on a horizontal plane as a direction reference for explanation, the end of the rectangular waveguide 223 away from the time delay control board 10 is the top of the rectangular waveguide 223, and the multiple rectangular waveguides 223 away from the time delay control board 10 can be understood as the middle and lower part, middle part, middle and upper part, top part, etc. of the rectangular waveguide 223 in the height direction, and the reinforcement plate 40 can be fixed on the middle part of the vertical side wall of the rectangular waveguide 223, the middle and lower part of the vertical side wall, the middle and upper part of the vertical side wall, the top wall, etc. When the height of the rectangular waveguide 223 is high, the rectangular waveguide 223 is prone to shaking, resulting in the problem of unstable coupling connection. By setting the reinforcement plate 40, the connection between each rectangular waveguide 223 and the time delay control board 10 can be made more stable.

[0064] In some embodiments of the present invention, see Figure 2 , a single signal simulator also includes a radar chip. A signal transmitting end 11 and a signal receiving end 12 are provided on the delay control board 10. The waveguide transmission structure 20 is located between the signal transmitting end 11 and the signal receiving end 12. A radar chip is also connected between the signal transmitting end 11 and the signal transmitting end 11. The amplitude controller outputs the amplitude-adjusted signal to the delay control board 10, and the delay is controlled through the waveguide transmission structure 20 on the delay control board 10. At the same time, the amplitude-adjusted signal is transmitted from the signal transmitting end 11 of the delay control board 10 to the radar chip. The signal output end of the delay control board 10 outputs the delayed signal to the radar chip. In this way, the delay and amplitude generated by the signal passing through the delay control board 10 can be detected by the radar chip.

[0065] Combination Figure 2 In each signal simulation device, the amplitude controller is named A n , a single signal simulator is named M n , RX n is the signal obtained by each signal receiving end 12 (used to simulate the signal of each propagation path), and n is a positive integer greater than or equal to 2. n After being synthesized by the power synthesizer, RX total , and then the delayed power distribution (coordinate diagram between the power combiner and the receiver) is obtained.

[0066] In some embodiments of the present invention, the signal multipath effect simulation system further includes a PC, which is connected to the signal receiver and is used to input instructions or output and display the delay power distribution. The PC can be understood as a computer.

[0067] 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 and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A signal multipath effect simulation system, characterized in that: include: A radio frequency signal generator, used for sending a radio frequency signal; A power divider, used for dividing the radio frequency signal into multiple signals; A plurality of signal simulation devices, wherein multiple signals are respectively input to the corresponding signal simulation devices, each of which is used to simulate signals with different delays, wherein the signal simulation device comprises an amplitude controller and a single signal simulator of a transmission connection, wherein the amplitude controller is used to control the amplitude of the signal, wherein the single signal simulator comprises a delay control board, a waveguide transmission structure and a radio frequency switch, wherein the waveguide transmission structure comprises a plurality of transmission paths, wherein the lengths of the transmission paths are different, wherein the radio frequency switch is used to selectively conduct the transmission paths, wherein the radio frequency switch and at least a part of the transmission paths are both arranged on the delay control board; A power synthesizer, connected to the plurality of signal simulation devices for synthesizing output signals of the plurality of signal simulation devices; A signal receiver is used to convert the composite signal into a time-delay power distribution.

2. The signal multipath effect simulation system as claimed in claim 1, characterized in that: The waveguide transmission structure includes multiple sections of grounded coplanar waveguides, two adjacent sections of the grounded coplanar waveguides are connected through the radio frequency switch, and at least two sections of the grounded coplanar waveguides are arranged in parallel.

3. The signal multipath effect simulation system as claimed in claim 1, characterized in that: The waveguide transmission structure includes a plurality of first transmission units connected in series, wherein the first transmission unit includes a first grounded coplanar waveguide and a second grounded coplanar waveguide connected in parallel, and the first end of the first grounded coplanar waveguide is connected to the first end of the second grounded coplanar waveguide through the radio frequency switch, and the second end of the first grounded coplanar waveguide is connected to the second end of the second grounded coplanar waveguide through the radio frequency switch, so that the first grounded coplanar waveguide and the second grounded coplanar waveguide are selectively conducted, and the lengths of the first grounded coplanar waveguide and the second grounded coplanar waveguide are different.

4. The signal multipath effect simulation system as claimed in claim 3, characterized in that: Two adjacent first transmission units are connected via a transmission connection waveguide, and two ends of the transmission connection waveguide are respectively connected to the radio frequency switches of the two first transmission units.

5. The signal multipath effect simulation system as claimed in claim 3, characterized in that: In each of the first transmission units, a length difference between the second grounded coplanar waveguide and the first grounded coplanar waveguide is a geometric progression.

6. The signal multipath effect simulation system as claimed in claim 3, characterized in that: The waveguide transmission structure also includes a plurality of second transmission units connected in series, wherein the first transmission unit and the second transmission unit are connected in series, and the second transmission unit includes a third grounded coplanar waveguide, two fourth grounded coplanar waveguides and a rectangular waveguide, wherein the two ends of the third grounded coplanar waveguide are respectively connected to the first ends of the two fourth grounded coplanar waveguides through the radio frequency switch, and the second ends of the two fourth grounded coplanar waveguides are coupled to the rectangular waveguide so that the rectangular waveguide and the third grounded coplanar waveguide are selectively conducted, and the transmission channels of the rectangular waveguides have different lengths.

7. The signal multipath effect simulation system as claimed in claim 6, characterized in that: The interior of the rectangular waveguide has the hollow transmission channel, both ends of the transmission channel have coupling windows, the two coupling windows are located on the same side wall of the rectangular waveguide, and the two coupling windows are respectively opposite to the second ends of the two fourth grounded coplanar waveguides.

8. The signal multipath effect simulation system as claimed in claim 7, characterized in that: The rectangular waveguide includes a first metal plate and a second metal plate, the first metal plate is provided with a first groove, the second metal plate is provided with a second groove, the first metal plate and the second metal plate are fixedly connected by fastening screws, and the first groove and the second groove are arranged opposite to each other to form the transmission channel.

9. The signal multipath effect simulation system as claimed in claim 7, characterized in that: The rectangular waveguide is vertically arranged on the delay control board, and each of the rectangular waveguides is arranged in sequence along the thickness direction thereof. A reinforcement plate is arranged at a position of the plurality of rectangular waveguides away from the delay control board, and the reinforcement plate is fixed to the plurality of rectangular waveguides.

10. The signal multipath effect simulation system according to any one of claims 1 to 9, characterized in that: The single signal simulator also includes a radar chip. A signal transmitting end and a signal receiving end are provided on the delay control board. The waveguide transmission structure is located between the signal transmitting end and the signal receiving end. The radar chip is also connected between the signal transmitting end and the signal transmitting end.

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