Inter-modulation signal response device based on complex filter-coupled matching network, nonlinear radar system having same, and inter-modulation signal response method based on complex filter-coupled matching network

Abstract

An embodiment of the present invention provides an inter-modulation signal response device based on a complex filter-coupled matching network, comprising: a reception antenna; a fundamental wave matching network for performing matching on a dual fundamental wave signal received by the reception antenna; a diode for generating a target inter-modulation signal and signals other than a target through the non-linear characteristics by receiving the double fundamental wave signal; and a complex filter-coupled matching network for attenuating the signals other than the target and matching the attenuated signals with the target inter-modulation signal to output a target inter-modulation signal. The complex filter-coupled matching network includes: a first matching attenuation stage for attenuating the signals other than the target; a low-pass stage for attenuating a frequency band not lower than that of the target inter-modulation signal; a skirt attenuation stage for attenuating a frequency band, which is adjacent to that of the target inter-modulation signal, of the signal passing through the low-pass stage; and a second matching attenuation stage for performing matching for outputting the target inter-modulation signal.

Description

Intermodulation signal responder based on a complex filter-coupled matching network, a nonlinear radar system having the same, and an intermodulation signal response method based on a complex filter-coupled matching network

[0001] The present invention relates to an intermodulation signal responder based on a complex filter-coupled matching network, a nonlinear radar system having the same, and an intermodulation signal response method based on a complex filter-coupled matching network, and more particularly, to an intermodulation signal responder based on a complex filter-coupled matching network that detects various electronic devices through a nonlinear signal that transmits a fundamental wave and is reflected due to nonlinear element characteristics of the electronic devices, a nonlinear radar system having the same, and an intermodulation signal response method based on a complex filter-coupled matching network.

[0002] This research was supported by the National Research Foundation of Korea (NRF) with funding from the Ministry of Science and ICT (No. RS-2023-00218972).

[0003] In general, a nonlinear radar system is a technology that can detect various electronic devices by transmitting a fundamental wave and using nonlinear signals (harmonics and intermodulation signals) reflected due to the nonlinear element characteristics of the electronic device.

[0004] Figure 1 shows an example of a conventional nonlinear radar system.

[0005] Nonlinear radar systems have diverse applications, including health monitoring, animal tracking, and atmospheric physics sensing. They possess valuable characteristics that enable the effective identification of electronic devices in noisy environments by analyzing fundamental frequency signals and nonlinear responses. Nonlinear transducers (harmonic and intermodulation signal transducers) are representative devices that enhance the effectiveness of nonlinear radar systems. Nonlinear transducers require optimization through fundamental signal suppression and matching of input and output signals to achieve high conversion gain for the target nonlinear signal.

[0006] Figure 2 is a block diagram showing a harmonic responder, which is a representative type of nonlinear responder. Figure 2 also shows a block diagram of a matching network of a conventional general harmonic responder. A representative model of a conventional general nonlinear responder is a harmonic responder, which is generally composed of an input matching network for the fundamental wave, a diode, and an output matching network for harmonics to maximize the output of harmonics. The fundamental wave matching network at the input stage performs matching in the frequency band of the input fundamental wave, and the diode, as a nonlinear element, generates a nonlinear signal (harmonic and intermodulation signal) from the transmitted fundamental wave signal. The harmonic matching network at the output stage performs matching of the nonlinear signal generated by the diode in the target harmonic frequency signal band. The nonlinear responder must be adjusted to achieve optimal performance in the desired frequency band by not only matching the input of the fundamental wave and the output of the nonlinear response signal, but also attenuating the fundamental wave output signal. However, because the input and output frequency bands differ by an integer multiple, a dual-band antenna that accommodates both frequency bands or a dual-band coupler is required. This significantly increases circuit complexity. Furthermore, using dual bands can increase the complexity of the radar transceiver.

[0007] The technical problem to be achieved by the present invention is to provide a cross-modulation signal responder that generates and outputs a cross-modulation signal by applying a dual fundamental wave to a diode.

[0008] The technical problem to be achieved by the present invention is to provide an intermodulation signal responder having a complex filter coupling matching network with sharp filter characteristics, which suppresses dual fundamental signals and converts intermodulation signal generation with high efficiency.

[0009] The technical problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0010] In order to achieve the above technical problem, one embodiment of the present invention is an intermodulation signal responder based on a complex filter-coupled matching network, which is provided in an electronic device and receives and processes a signal transmitted by a nonlinear sensing device of a nonlinear radar system and then outputs a target intermodulation signal, the intermodulation signal responder comprising: a receiving antenna which receives a dual fundamental signal transmitted by the nonlinear sensing device; a fundamental matching network which performs matching on the dual fundamental signal received by the receiving antenna; a diode which receives the dual fundamental signal passed through the fundamental matching network and generates a target intermodulation signal and signals other than the target through nonlinear characteristics; and a complex filter-coupled matching network which attenuates signals other than the target and matches the target intermodulation signal to output the target intermodulation signal, wherein the complex filter-coupled matching network comprises: a first matching attenuation stage which attenuates signals other than the target among signals from the diode; a low-pass stage which attenuates a frequency band higher than the target intermodulation signal with respect to a signal passed through the first matching attenuation stage; A composite filter-coupled matching network-based intermodulation signal responder is provided, comprising: a skirt attenuation stage for attenuating a frequency band adjacent to the target intermodulation signal for a signal passing through the low-pass stage; and a second matching attenuation stage for performing matching for outputting the target intermodulation signal for a signal passing through the skirt attenuation stage.

[0011] In order to achieve the above technical problem, another embodiment of the present invention is a nonlinear radar system that detects an electronic device by capturing an intermodulation signal reflected by nonlinear element characteristics of an electronic device that has received a signal, the nonlinear sensing device including a transmitter that transmits a dual fundamental signal, a receiver that captures an intermodulation signal reflected by nonlinear element characteristics of the electronic device, and a processor connected to the receiver to detect and identify the electronic device based on the reflected intermodulation signal; and an intermodulation signal responder based on a complex filter-coupled matching network, which is provided in the electronic device and receives and processes the signal transmitted by the transmitter and then outputs an intermodulation signal, the intermodulation signal responder based on a complex filter-coupled matching network, comprising: a receiving antenna that receives the dual fundamental signal transmitted by the transmitter; a fundamental matching network that performs matching on the dual fundamental signal received by the receiving antenna; a diode that receives the dual fundamental signal that has passed through the fundamental matching network and generates a target intermodulation signal and other signals other than the target through nonlinear characteristics; And a composite filter combination matching network that attenuates signals other than the target and matches the target intermodulation signal to output the target intermodulation signal, wherein the composite filter combination matching network includes: a first matching attenuation stage that attenuates signals other than the target among signals from the diode; a low-pass stage that attenuates a frequency band higher than the target intermodulation signal for a signal that has passed through the first matching attenuation stage; a skirt attenuation stage that attenuates a frequency band adjacent to the target intermodulation signal for a signal that has passed through the low-pass stage; and a second matching attenuation stage that performs matching for outputting the target intermodulation signal for a signal that has passed through the skirt attenuation stage.

[0012] In order to achieve the above technical problem, another embodiment of the present invention provides a method for responding to an intermodulation signal based on a complex filter-coupled matching network in a nonlinear radar system, the method comprising: a nonlinear sensing device that detects an electronic device by transmitting a signal and receiving a response signal from an external electronic device; and an intermodulation signal responder based on a complex filter-coupled matching network that receives a signal from the nonlinear sensing device and transmits a response signal, the method comprising: a step in which a transmitter of the nonlinear sensing device transmits a dual fundamental wave; a step in which an intermodulation signal responder based on a complex filter-coupled matching network provided in an electronic device receives the dual fundamental wave and matches it with a fundamental wave matching network; a step in which a diode, to which the dual fundamental wave passed through the fundamental wave matching network is input, generates a target intermodulation signal and signals other than the target through nonlinearity; a step in which the complex filter-coupled matching network receives a signal output from the diode, matches the target intermodulation signal, and attenuates signals other than the target, thereby selectively outputting the target intermodulation signal; And a step of detecting the electronic device by receiving the target intermodulation signal by the receiving unit of the nonlinear sensing device, and the step of outputting the target intermodulation signal by the complex filter coupled matching network comprises: a step in which a first matching attenuation stage attenuates signals other than the target among signals from the diode; a step in which a low-pass stage attenuates a frequency band above a cutoff frequency adjacent to the target intermodulation signal for a signal that has passed through the first matching attenuation stage; a step in which a skirt attenuation stage attenuates a frequency band adjacent to the target intermodulation signal for a signal that has passed through the low-pass stage; and a step in which a second matching attenuation stage performs matching for outputting the target intermodulation signal for a signal that has passed through the skirt attenuation stage.

[0013] According to an embodiment of the present invention, a complex filter coupling matching network forms an attenuation axis in a specific frequency band to have sharp filter characteristics for input / output signals in adjacent frequency bands and performs a matching function for a target intermodulation signal, a nonlinear radar system having the same, and an intermodulation signal response method based on a complex filter coupling matching network can be provided.

[0014] According to an embodiment of the present invention, a multi-modulation responder based on a complex filter coupling matching network can reduce the complexity of a transmitter and receiver by having input and output signals in adjacent frequency bands.

[0015] According to an embodiment of the present invention, a composite filter combination matching network can selectively output a target intermodulation output signal by forming a sharp attenuation axis, and can perform matching for the target output signal to have a high conversion gain, so that it can be utilized in various RF applications in communication and radar systems.

[0016] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the detailed description of the present invention or the composition of the invention described in the claims.

[0017] Figure 1 shows an example of a conventional nonlinear radar system.

[0018] Figure 2 is a block diagram showing a harmonic responder, which is a representative type of nonlinear responder.

[0019] Figure 3 illustrates a nonlinear radar system according to one embodiment of the present invention.

[0020] FIG. 4 is a block diagram illustrating a complex filter coupling matching network-based intermodulation signal responder according to one embodiment of the present invention.

[0021] Figure 5 shows a signal received by the antenna of the intermodulation signal responder of Figure 4 as a dual fundamental wave transmitted by the transmitter of Figure 3.

[0022] Fig. 6 shows the target intermodulation signal as the output of the intermodulation signal responder shown in Fig. 4.

[0023] Figure 7 illustrates an example of the composite filter combination matching network described in Figure 4.

[0024] Figure 8 shows another example of the composite filter combination matching network described in Figure 4.

[0025] Figure 9 shows a modified example of the composite filter combination matching network described in Figure 7.

[0026] Figure 10 shows a modified example of the composite filter combination matching network described in Figure 8.

[0027] Fig. 11 is a graph showing the S-parameter characteristics of the composite filter coupling matching network of the intermodulation responders shown in Figs. 7 and 8.

[0028] FIG. 12 illustrates a method for responding to a multi-modulation signal based on a complex filter coupling matching network according to one embodiment of the present invention.

[0029] The present invention is susceptible to various modifications and variations, and specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosed form, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention. Throughout the description of each drawing, similar reference numerals have been used to designate similar components.

[0030] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0031] Hereinafter, with reference to the attached drawings, a preferred embodiment of the present invention will be described in more detail.

[0032] Fig. 3 illustrates a nonlinear radar system (1) according to one embodiment of the present invention. The nonlinear radar system (1) of this embodiment includes a nonlinear sensing device (100) that transmits a signal and receives a response signal from an external electronic device to detect the electronic device, and a complex filter-coupled matching network-based intermodulation signal responder (200) (hereinafter, intermodulation signal responder) that receives a signal from the nonlinear sensing device (100) and transmits a response signal.

[0033] A nonlinear sensing device (100) may include a transmitter (110) that transmits a fundamental wave signal, a receiver (120) that captures an intermodulation signal reflected (responded to) by the nonlinear element characteristics of an electronic device, a processor (not shown) that is connected to the receiver (120) and detects and identifies the electronic device based on the reflected intermodulation signal, and an output unit (not shown) that displays information detected by the processor to the user. In the present embodiment, the transmitter (110) may transmit a first frequency signal (f1) and a second frequency signal (f2) as two fundamental waves (dual fundamental waves). The intermodulation signal responder (200) may receive the dual fundamental waves, attenuate and match them, and output an intermodulation signal having an intermodulation frequency of, for example, 2f1-f2. Of course, the intermodulation frequency may be set to various other than 2f1-f2. The intermodulation signal responder (200) may be formed by mounting components on a printed circuit board, for example, and may be provided in an electronic device including a semiconductor device such as a smart phone, a smart watch, or a nonlinear tag. The receiving unit (120) of the nonlinear sensing device (100) may be set to receive a target intermodulation signal. The dual fundamental wave transmitted from the transmitting unit (110) of the nonlinear sensing device (100) may be reflected by a person or an object as illustrated in FIG. 3, and this fundamental reflection wave may have the same frequency as the fundamental wave. This fundamental reflection wave is not received by the receiving unit (120). The processing unit may process the intermodulation signal received by the receiving unit (120) to detect the presence and characteristics of an electronic device, and the output unit may display the detection result.

[0034] Fig. 4 is a block diagram showing a complex filter coupling matching network-based intermodulation signal responder (200) according to one embodiment of the present invention. Fig. 5 shows a signal received by the receiving antenna (210) of the intermodulation signal responder (200) of Fig. 4 as a dual fundamental wave transmitted by the transmitter (110) of Fig. 3. Fig. 6 shows a target intermodulation signal as an output of the intermodulation signal responder (200) shown in Fig. 4.

[0035] In the present embodiment, the intermodulation signal responder (200) may be provided in a manner such as being built into the electronic device described above. The intermodulation signal responder (200) may receive a dual fundamental wave signal transmitted from the transmitter (110) of the nonlinear sensing device (100), nonlinearly modulate it, attenuate it, and filter it to output a target intermodulation signal. The intermodulation signal responder (200) may include a receiving antenna (210), a fundamental wave matching network (220), a diode (230), a complex filter combination matching network (240), and a transmitting antenna (250).

[0036] The receiving antenna (210) can receive a dual fundamental wave signal transmitted by the transmitter (110) of the nonlinear sensing device (100) as an input signal. The dual fundamental wave can include two frequency signals, i.e., a first frequency signal (f1) and a second frequency signal (f2).

[0037] The fundamental matching network (220) (input matching network) is connected to the receiving antenna (210) and can perform matching on the received dual fundamental signal.

[0038] The diode (230) can receive the dual fundamental signal that has passed through the fundamental matching network (220) and generate a target intermodulation signal and other non-target signals through the non-linear characteristics of the diode (230). When the dual fundamental signal is applied to the diode (230), the target intermodulation signal (e.g., 2f1-f2) can be generated due to the non-linear characteristics of the diode (230). In this process, other signals other than the target, for example, harmonics (e.g., 2f1, 2f2) and non-target intermodulation signals (e.g., 2f2-f1), can also be generated.

[0039] The composite filter coupling matching network (240) is provided between the diode (230) and the output terminal of the intermodulation signal responder (200) to effectively attenuate signals other than the target. That is, the composite filter coupling matching network (240) can perform attenuation of the dual fundamental wave and matching of the target intermodulation signal. Specifically, the composite filter coupling matching network (240) can attenuate or filter the dual fundamental wave signals (f1, f2), harmonic signals (2f1, 2f2), and the non-target intermodulation signal (2f2-f1), and output the target intermodulation signal (e.g., 2f1-f2). The target intermodulation signal can be selectively output through the composite filter coupling matching network (240). That is, the composite filter coupling matching network (240) can provide optimal output matching for the target intermodulation signal to maximize the output. The transmission antenna (250) can automatically transmit the target intermodulation signal to the outside.

[0040] The composite filter combination matching network (240) may include a matching attenuation stage (241, 244), a low-pass stage (242), and a skirt attenuation stage (243). The matching attenuation stage and the skirt attenuation stage (243) may suppress signals by forming an attenuation axis in the frequency band of other harmonics and non-target intermodulation signals other than the target intermodulation signal. The matching attenuation stage may attenuate unwanted signals while simultaneously matching signals at a specific frequency to amplify the target intermodulation signal. In the present disclosure, “matching” may refer to a process of adjusting the characteristics of a filter to optimize signal processing at a specific frequency. This may allow the target signal intermodulation signal to be output more clearly and powerfully. Through matching, the performance of the composite filter combination matching network (240) is improved, and reflection and loss of signals in the intermodulation signal responder (200) are reduced, thereby improving the signal-to-noise ratio (SNR) of the overall system and increasing the accuracy and reliability of the signals.

[0041] In this embodiment, the matching attenuation stage may include a first matching attenuation stage (241) connected to a diode (230) and a second matching attenuation stage (244) positioned between the output terminal of the complex filter combination matching network (240) and the first matching attenuation stage (241). The first matching attenuation stage (241) may attenuate signals other than the target intermodulation signal among nonlinear signals from the diode (230). The first matching attenuation stage (241) reduces unwanted signals in the initial stage, thereby contributing to increasing the processing efficiency of the subsequent stage. In this embodiment, the first matching attenuation stage (241) may have attenuation characteristics at a first frequency.

[0042] A low-pass stage (242) and a skirt attenuation stage (243) may be provided between the first matching attenuation stage (241) and the second matching attenuation stage (244). The low-pass stage (242) and the skirt attenuation stage (243) may additionally suppress harmonics and non-target intermodulation signals except for the frequency band of the target intermodulation signal (2f1 - f2). The low-pass stage (242) exhibits attenuation characteristics over a frequency band higher than the target intermodulation signal for a signal that has passed through the first matching attenuation stage (241), thereby suppressing unnecessary signals. The low-pass stage (242) plays an important role in allowing the network to selectively pass only the target intermodulation signal. In the present embodiment, the low-pass stage (242) may have attenuation characteristics above a cutoff frequency (fc) adjacent to the target intermodulation signal.

[0043] The skirt attenuation stage (243) is provided between the low-pass stage (242) and the second matching attenuation stage (244) to form an attenuation axis in a frequency band other than the target intermodulation signal, thereby removing unnecessary signals from the signal passing through the low-pass stage (242). The skirt attenuation stage (243) contributes to selective suppression of the signal together with the matching attenuation stage. The skirt attenuation stage (243) may play a role in attenuating a frequency band adjacent to the target intermodulation signal. In the present embodiment, the skirt attenuation stage (243) may have attenuation characteristics at the second frequency.

[0044] The second matching attenuation stage (244) is located on the output side and finally matches the target intermodulation signal to the signal that has passed through the skirt attenuation stage (243), thereby ensuring optimal performance when the target intermodulation signal is output. Matching at this stage maximizes the signal conversion gain and ensures the quality of the output signal. In the present embodiment, the second matching attenuation stage (244) may have attenuation characteristics at a third frequency.

[0045] In this way, the configuration of the composite filter combination matching network (240) is designed to enable highly selective filtering. When the dual fundamental input signals (f1, f2) are converted into nonlinear signals (e.g., 2f1 - f2) through the diode (230), undesired frequency signals (harmonics and non-target intermodulation signals) may be generated together. Each stage (each attenuation stage) of the network can serve to effectively extract and amplify only the target intermodulation signal by providing attenuation in a specific frequency band or emphasizing the desired signal. That is, the composite filter combination matching network (240) forms sharp attenuation axes at the fundamental waves (f1, f2), harmonics (2f1, 2f2), and non-target intermodulation signals (e.g., 2f2 - f1). Accordingly, as described above, the input signals (f1, f2) and the output signal (2f1-f2) can have high separation even though they are adjacent signal bands, and as a result, the target intermodulation signal can be selectively output.

[0046] The design of the composite filter-coupled matching network (240) can focus on achieving high conversion gain through attenuation of the input dual fundamental signal and matching within the frequency band of the target output intermodulation signal. Through precise tuning and interaction of these components, the composite filter-coupled matching network (240) provides high signal conversion efficiency and superior selectivity. This enables nonlinear radar systems to achieve higher accuracy and reliability in the detection and identification of electronic devices, while also improving performance while reducing system complexity.

[0047] FIG. 7 illustrates an example of a composite filter combination matching network (240) described in FIGS. 4 to 6.

[0048] In the composite filter combination matching network (240) presented in Fig. 7, the first matching attenuation stage (241), the low-pass stage (242), the skirt attenuation stage, and the second matching attenuation stage (244) are composed of inductors and capacitors. A diode (230) is connected to the input of the first matching attenuation stage (241), and the second matching attenuation stage (244) is provided in front of the output stage. There may be various ways to implement the skirt attenuation stage (243), and this may vary depending on the design purpose and specific frequency band. In the embodiment presented in Fig. 7, the skirt attenuation stage (243) may be composed of an inductor and a capacitor.

[0049] In this embodiment, the first matching attenuation stage (241), the second matching attenuation stage (244), and the skirt attenuation stage (243) have an LC filter network structure in which series inductors are arranged in series on a transmission line and an LC (inductor-capacitor) series resonant circuit is connected in parallel between the series inductors. Using this LC filter network, resonance can be generated at specific frequencies (e.g., f1, f2, f3) to form an attenuation axis. That is, the coupling between the matching attenuation stage and the skirt attenuation stage (243) forms a structure in which a series resonant circuit composed of an inductor (L) and a capacitor (C) is connected in parallel, and has an attenuation axis at a resonant frequency expressed by the following formula.

[0050]

[0051] The low-pass stage (242) can pass or block a signal by setting a cutoff frequency (fc) and having an attenuation characteristic above the cutoff frequency. The low-pass stage (242) can be implemented as a T-network type low-pass filter composed of series inductors arranged in series on a transmission line and capacitors connected between the series inductors. The low-pass stage (242) can attenuate a signal above a cutoff frequency adjacent to a target intermodulation signal. Here, the inductor and capacitor can be provided with fixed values, thereby defining the attenuation and pass characteristics in a specific frequency band.

[0052] Impedance matching is achieved at the portion where the low-pass stage (242), the skirt attenuation stage (243), and the matching attenuation stage are coupled to each other, and the combination of the low-pass stage (242), the skirt attenuation stage (243), and the matching attenuation stage can operate as a series inductor to optimize the final output impedance for the target intermodulation signal. In order to match the impedance of the diode (230) and the parallel resonant circuit for the aforementioned attenuation axis (i.e., a structure in which a series resonant circuit consisting of an inductor (L) and a capacitor (C) between the matching attenuation stage and the skirt attenuation stage (243) is connected in parallel), the first matching attenuation stage (241) may have an additional circuit in addition to the LC (inductor-capacitor) filter network. This additional circuit may be implemented as a circuit element having an impedance that changes the structure, or may be implemented as a transmission line.

[0053] FIG. 8 illustrates another example of the composite filter combination matching network (240) described in FIGS. 4 to 6.

[0054] In the composite filter combination matching network (240) shown in FIG. 8, the first matching attenuation stage (241), the low-pass stage (242), the skirt attenuation stage (243), and the second matching attenuation stage (244) can be implemented with serial stubs (240a) arranged in series on the transmission line and parallel stubs (240b) connected between the serial stubs (240a) and connected in parallel with each other. The stub is a part of a circuit with specific electrical characteristics and can be used to adjust an electrical load at a specific point on the transmission line or to provide a filtering effect. The stub can be connected to the transmission line and serve to adjust the reflection or transmission of radio waves, thereby achieving signal strengthening or attenuation in a desired frequency band. In this embodiment, the parallel stubs can short-circuit or block signals at specific frequencies, and the series stubs can control the impedance change of the signal and the signal in a specific frequency band to adjust the attenuation and pass characteristics of the first matching attenuation stage (241), the low-pass stage (242), the skirt attenuation stage (243), and the second matching attenuation stage (244). In this embodiment, the first matching attenuation stage (241), the skirt attenuation stage (243), and the second matching attenuation stage (244) can form attenuation axes through λ / 4 parallel open stubs for attenuation frequencies (e.g., f1, f2, f3). The length and width of the open stub of the low-pass stage (242) can be determined so that the low-pass stage (242) can have suppression characteristics above the cutoff frequency. The length and width of the serial transmission line can be determined so that impedance matching can be achieved when the first matching attenuation stage (241), the low-pass stage (242), the skirt attenuation stage (243), and the second matching attenuation stage (244) are combined. The first matching attenuation stage (241) located behind the diode (230) can further include an additional circuit in front of the λ / 4 open stub forming the aforementioned attenuation axis. This additional circuit can be provided for matching between the impedance of the diode (230) and the open stub forming the aforementioned attenuation axis.

[0055] Fig. 9 shows a modified example of the composite filter combination matching network (240) described in Fig. 7.

[0056] In the embodiment shown in Fig. 9, a first matching attenuation stage (241), M low-pass stages (242), N skirt attenuation stages (243), and a second matching attenuation stage (244) are provided between a diode (230) and an output stage. The number of low-pass stages (242) is M, and the number of skirt attenuation stages (243) is N, and it has an extended structure compared to the complex filter coupling matching network (240) shown in Fig. 7. Each stage is implemented with an inductor and a capacitor. The output side of the diode (230) is connected to one side of the M low-pass stages (242), and the M low-pass stages (242) perform an attenuation function for a dual fundamental wave signal. The M low-pass stages (242) have M set cutoff frequencies (f C1 , ..., f CM ) The element values ​​can be set so that the signal suppression function can be performed in each of the above signal bands. That is, since there are M low-pass stages (242), the cutoff frequency of the low-pass stages (242) can be expanded to M to superimpose the low-pass function.

[0057] In addition, the composite filter combination matching network (240) includes N skirt attenuation stages (243) connected to the other side of M low-pass stages (242) to perform additional attenuation for the dual fundamental signal and the target intermodulation signal. Since there are N skirt attenuation stages (243), the attenuation frequency of the skirt attenuation stages (243) is N attenuation frequencies (f1, ..., f N ) can be extended to N damping frequencies (f1, ..., f) by N skirt damping stages (243). N ) is the attenuation frequency (f) of the matching attenuation stage. N+1 , f N+2 ) with harmonic frequencies for the fundamental and attenuation frequencies (f1, ..., f) for intermodulation signals other than the target intermodulation signal.N , f LN+1 , f N+2 ) to have a λ / 4 open stub. An additional circuit may be provided in the first matching damping stage (241) for matching between the impedance of the diode (230) and the parallel resonant circuit forming the aforementioned damping axis.

[0058] Fig. 10 shows a modified example of the composite filter combination matching network (240) described in Fig. 8.

[0059] In the embodiment shown in Fig. 10, the composite filter coupling matching network (240) has an extended configuration with a first matching attenuation stage (241), M low-pass stages (242), N skirt attenuation stages (243), and a second matching attenuation stage (244) between the diode (230) and the output stage, each stage being implemented with a stub and a transmission line. The M low-pass stages (242) are connected to the diode (230) to perform an attenuation action on a dual fundamental wave signal and can superimpose a low-pass function. That is, M cutoff frequencies (f C1 , ..., f CM ) The length and width of the transmission line and stub can be set so that the signal suppression function can be performed in each ideal signal band.

[0060] N skirt attenuation stages (243) are connected to the low-pass stage (242) to perform additional attenuation for the dual fundamental wave signal. N attenuation frequencies (f1, ..., f) by N skirt attenuation stages (243) N ) is the attenuation frequency of the matching damping stage ( fN+1 , f N+2 ) with harmonic frequencies for the fundamental wave and attenuation frequencies (f1, ..., f) for intermodulation signals other than the target intermodulation signal. N , f LN+1 , f N+2) to have a λ / 4 open stub. Based on the determined transmission line and stub, the first matching attenuation stage (241) may further include an additional circuit for matching between the impedance of the diode (230) and the open stub for the aforementioned attenuation axis.

[0061] FIG. 11 is a graph showing the S-parameter characteristics of the composite filter coupling matching network (240) of the intermodulation responder illustrated in FIGS. 7 and 8.

[0062] Fig. 11 is a graph showing the S parameter characteristics of a 2.3 GHz intermodulation signal responder (200) having a complex filter coupling matching network (240) as presented in Fig. 7 or 8. It can be confirmed that the intermodulation signal responder (200) has a very large insertion loss in the dual fundamental band, i.e., the first frequency (f1) of 2.4 GHz as an input signal and the second frequency (f2) of 2.5 GHz, whereas it is properly matched and has almost no reflection loss in the target intermodulation signal band (2f1-f2) of 2.3 GHz as an output signal, which is an intermodulation signal.

[0063] FIG. 12 illustrates a method for responding to a multi-modulation signal based on a complex filter coupling matching network according to one embodiment of the present invention.

[0064] In a complex filter-coupled matching network-based intermodulation signal response method applied to a nonlinear radar system, which includes a nonlinear sensing device that detects an electronic device by transmitting a signal and receiving a response signal from an external electronic device, and an intermodulation signal responder based on a complex filter-coupled matching network that receives a signal from the nonlinear sensing device and transmits a response signal, first, a transmitter of the nonlinear sensing device transmits a dual fundamental wave (S10). An intermodulation signal responder based on a complex filter-coupled matching network provided in the electronic device receives the dual fundamental wave and matches it with a fundamental wave matching network (S20). A diode, into which the dual fundamental wave passed through the fundamental wave matching network is input, generates a target intermodulation signal and other signals other than the target through nonlinearity (S30). The complex filter-coupled matching network receives a signal output from the diode, matches the target intermodulation signal, and attenuates other signals other than the target to selectively output the target intermodulation signal (S40). A receiver of the nonlinear sensing device receives the target intermodulation signal and detects the electronic device (S50).

[0065] In step 40) where the complex filter combination matching network outputs the target intermodulation signal, the first matching attenuation stage can attenuate signals other than the target among the signals from the diode (S41). The low-pass stage can attenuate a frequency band above a cutoff frequency adjacent to the target intermodulation signal for a signal that has passed through the first matching attenuation stage (S42). The skirt attenuation stage can attenuate a frequency band adjacent to the target intermodulation signal for a signal that has passed through the low-pass stage (S43). The second matching attenuation stage can perform matching for outputting the target intermodulation signal for a signal that has passed through the skirt attenuation stage (S44).

[0066] In the step (S20) where a multi-modulation signal responder based on a complex filter coupling matching network equipped in an electronic device receives a dual fundamental wave and matches it with a fundamental wave matching network, a receiving antenna can receive a first frequency signal (f1) and a second frequency signal (f2) as a dual fundamental wave signal.

[0067] In the step of generating a nonlinear signal (S30), the diode receives a first frequency signal (f1) and a second frequency signal (f2) and generates a target intermodulation signal (2f1-f2), but can generate harmonic signals (2f1, 2f2) and a non-target intermodulation signal (2f2-f1) as signals other than the target during the generation process.

[0068] In the step (S40) where the composite filter combination matching network outputs a target intermodulation signal, the composite filter combination matching network can output the target intermodulation signal by attenuating or filtering the dual fundamental signal, the harmonic signal, and the non-target intermodulation signal.

[0069] Attenuation (S41) by the first matching attenuation stage can be performed at a first frequency. Attenuation (S44) by the second matching attenuation stage can be performed at a third frequency. The step (S42) in which the low-pass stage suppresses an unnecessary signal may be performed by a low-pass stage provided between the first matching attenuation stage and the skirt attenuation stage at a cutoff frequency (fc) or higher. The step (S43) in which the skirt attenuation stage forms an attenuation axis to suppress a signal may be performed by a skirt attenuation stage provided between the low-pass stage and the second matching attenuation stage at a second frequency.

[0070] According to an embodiment of the present invention, a cross-modulation signal responder (200) and a method thereof can be provided, which includes a complex filter coupling matching network that generates a cross-modulation signal by applying a dual fundamental wave to a diode (230) and selectively outputs only the cross-modulation signal while suppressing the dual fundamental wave signal.

[0071] According to an embodiment of the present invention, the complexity associated with a dual-band antenna or coupler required for a conventional nonlinear response system can be reduced, and this reduction in complexity does not degrade the performance of the system, but rather improves the performance by ensuring optimal output matching and maximizing the output.

[0072] Embodiments of the present invention can be applied to the field of nonlinear radar systems, and can provide a device and method capable of more precisely detecting various electronic devices through nonlinear signals reflected due to nonlinear characteristics of electronic device components.

[0073] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will readily appreciate that the present invention can be readily modified into other specific forms without altering the technical spirit or essential characteristics of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single entity may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined manner.

[0074] The scope of the present invention is indicated by the claims described below, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

[0075] [Explanation of symbols]

[0076] Nonlinear radar system (1)

[0077] Nonlinear sensing device (100)

[0078] Transmitter (110)

[0079] Receiver (120)

[0080] Intermodulation signal responder (200)

[0081] Receiving antenna (210)

[0082] Fundamental wave matching network (220)

[0083] diode (230)

[0084] Composite filter combination matching network (240)

[0085] Serial stub (240a)

[0086] Parallel stub (240b)

[0087] First matching damping stage (241)

[0088] Low-pass stage (242)

[0089] Skirt damping section (243)

[0090] Second matching damping stage (244)

[0091] Transmitting antenna (250)

Claims

1. An intermodulation signal responder based on a complex filter coupling matching network, which is equipped in an electronic device, receives and processes a signal transmitted by a nonlinear sensing device of a nonlinear radar system, and then outputs a target intermodulation signal. A receiving antenna for receiving a dual fundamental wave signal transmitted by a nonlinear sensing device; A fundamental matching network that performs matching on the dual fundamental signal received by the above receiving antenna; A diode that receives a dual fundamental wave signal that has passed through the fundamental wave matching network and generates a target intermodulation signal and other signals other than the target through nonlinear characteristics; and It includes a complex filter combination matching network that attenuates signals other than the target signal and matches the target intermodulation signal to output the target intermodulation signal. The above complex filter combination matching network is, A first matching attenuation stage for attenuating signals other than the target signals from the above diode; A low-pass stage that attenuates a frequency band higher than the target intermodulation signal for a signal that has passed through the first matching attenuation stage; A skirt attenuation stage that attenuates a frequency band adjacent to the target intermodulation signal for a signal passing through the low-pass stage; and An intermodulation signal responder based on a complex filter-coupled matching network, comprising a second matching attenuation stage that performs matching for outputting the target intermodulation signal for a signal passing through the skirt attenuation stage.

2. In claim 1, The above receiving antenna receives the first frequency signal and the second frequency signal as the dual fundamental wave signal. The diode receives the first frequency signal and the second frequency signal and generates a target intermodulation signal, but in the generation process, generates a harmonic signal and a non-target intermodulation signal as signals other than the target. An intermodulation signal responder based on a complex filter coupling matching network, wherein the complex filter coupling matching network outputs the target intermodulation signal by attenuating or filtering a dual fundamental signal, a harmonic signal, and an intermodulation signal other than the target.

3. In claim 2, The above first matching attenuation stage has attenuation characteristics at the first frequency, The low-pass stage provided between the first matching attenuation stage and the skirt attenuation stage has an attenuation characteristic above a cutoff frequency adjacent to the target intermodulation signal, The skirt attenuation stage provided between the low-pass stage and the second matching attenuation stage has attenuation characteristics at the second frequency, An intermodulation signal responder based on a complex filter-coupled matching network, wherein the second matching attenuation stage has attenuation characteristics at a third frequency.

4. In claim 3, The above first matching damping stage, skirt damping stage and second matching damping stage are, The series inductors and the LC (inductor-capacitor) series resonant circuit arranged in series on the transmission line have an LC filter network structure connected in parallel between the series inductors, thereby forming attenuation axes that generate resonance at the first frequency, the second frequency, and the third frequency, respectively. The above low-pass stage is implemented as a T-network type low-pass filter consisting of series inductors arranged in series on a transmission line and capacitors connected between the series inductors, and is an intermodulation signal responder based on a complex filter coupling matching network that attenuates signals above a set cutoff frequency.

5. In claim 3, The above first matching attenuation stage, low-pass stage, skirt attenuation stage and second matching attenuation stage are implemented with serial stubs arranged in series on the transmission line and parallel stubs connected in parallel between the serial stubs, The above parallel stubs can short-circuit or block signals at specific frequencies, and the above series stubs can control the change in impedance of signals and signals in specific frequency bands to adjust the attenuation and pass characteristics of the first matching attenuation stage, the low-pass stage, the skirt attenuation stage, and the second matching attenuation stage. An intermodulation signal responder based on a composite filter coupling matching network, wherein the first matching attenuation stage, the skirt attenuation stage, and the second matching attenuation stage form an attenuation axis through a λ / 4 parallel open stub for the attenuation frequency.

6. In claim 4, The composite filter combination matching network includes M low-pass stages connected to the diodes to perform an attenuation function for the dual fundamental signal, and the M low-pass stages have element values set so that they can perform a signal suppression function in a signal band above each of the M cutoff frequencies. A composite filter coupling matching network-based intermodulation signal responder, wherein the composite filter coupling matching network includes N skirt attenuation stages connected to the low-pass stage to perform additional attenuation operations on the dual fundamental wave signal and the target intermodulation signal, and the N attenuation frequencies by the N skirt attenuation stages, together with the attenuation frequency of the second matching attenuation stage, form a resonant circuit for harmonic frequencies for the fundamental wave and attenuation frequencies for intermodulation signals other than the target intermodulation signal.

7. In claim 5, The composite filter combination matching network includes M low-pass stages connected to diodes to perform an attenuation function on the dual fundamental signal, and the parallel stubs are adjusted so that the M low-pass stages can perform a signal suppression function in a signal band above each of the M cutoff frequencies. A composite filter coupling matching network-based intermodulation signal responder, wherein the composite filter coupling matching network includes N skirt attenuation stages connected to the low-pass stage to perform additional attenuation operations on the dual fundamental wave signal and the target intermodulation signal, and the N attenuation frequencies by the N skirt attenuation stages, together with the attenuation frequency of the second matching attenuation stage, form a resonant circuit for harmonic frequencies for the fundamental wave and attenuation frequencies for intermodulation signals other than the target intermodulation signal.

8. A nonlinear radar system that detects electronic devices by capturing intermodulation signals reflected by the nonlinear element characteristics of the electronic device that received the signal. A nonlinear sensing device including a transmitter for transmitting a dual fundamental wave signal, a receiver for capturing a cross-modulation signal reflected by a nonlinear element characteristic of an electronic device, and a processor connected to the receiver for detecting and identifying the electronic device based on the reflected cross-modulation signal; and The electronic device includes a multi-modulation signal responder based on a complex filter coupling matching network that receives and processes a signal transmitted by the transmitter and then outputs a multi-modulation signal. Intermodulation signal responder based on complex filter combination matching network, A receiving antenna for receiving a dual fundamental wave signal transmitted by the above transmitter; A fundamental matching network that performs matching on the dual fundamental signal received by the above receiving antenna; A diode that receives a dual fundamental wave signal that has passed through the fundamental wave matching network and generates a target intermodulation signal and other signals other than the target through nonlinear characteristics; and It includes a complex filter combination matching network that attenuates signals other than the target signal and matches the target intermodulation signal to output the target intermodulation signal. The above complex filter combination matching network is, A first matching attenuation stage for attenuating signals other than the target signals from the above diode; A low-pass stage that attenuates a frequency band higher than the target intermodulation signal for a signal that has passed through the first matching attenuation stage; A skirt attenuation stage that attenuates a frequency band adjacent to the target intermodulation signal for a signal passing through the low-pass stage; and A nonlinear radar system comprising a second matching attenuation stage that performs matching for outputting the target intermodulation signal for a signal passing through the skirt attenuation stage.

9. In claim 8, The above receiving antenna receives the first frequency signal and the second frequency signal as the dual fundamental wave signal, The diode receives the first frequency signal and the second frequency signal and generates a target intermodulation signal, but in the generation process, generates a harmonic signal and a non-target intermodulation signal as signals other than the target. A nonlinear radar system, wherein the above-mentioned complex filter combination matching network outputs the target intermodulation signal by attenuating or filtering the dual fundamental signal, the harmonic signal, and the non-target intermodulation signal, and further includes a transmitting antenna that automatically transmits the target intermodulation signal output from the second matching attenuation stage.

10. In a nonlinear radar system including a nonlinear sensing device that detects an electronic device by transmitting a signal and receiving a response signal from an external electronic device, and a complex filter coupling matching network-based intermodulation signal responder that receives a signal from the nonlinear sensing device and transmits a response signal, a method for intermodulation signal response based on a complex filter coupling matching network, A step in which the transmitter of the nonlinear sensing device transmits a dual fundamental wave; A step of receiving a dual fundamental wave and matching it with a fundamental wave matching network by a multi-filter coupling matching network-based intermodulation signal responder equipped in an electronic device; A step in which a diode, which receives a dual fundamental wave that has passed through a fundamental wave matching network, generates a target intermodulation signal and other signals other than the target through nonlinearity; A step of a complex filter combination matching network receiving a signal output from a diode, matching the target intermodulation signal, and attenuating signals other than the target to selectively output the target intermodulation signal; and A step of detecting the electronic device by receiving the target intermodulation signal by the receiving unit of the nonlinear sensing device, The step of the above complex filter combination matching network outputting a target intermodulation signal is: A step in which the first matching attenuation stage attenuates signals other than the target signals from the diode; A step of attenuating a frequency band above a cutoff frequency adjacent to the target intermodulation signal for a signal that has passed through the first matching attenuation stage by a low-pass stage; A step of attenuating a frequency band adjacent to the target intermodulation signal with respect to a signal that has passed through the low-pass stage by a skirt attenuator; and A method for responding to an intermodulation signal based on a complex filter coupled matching network, comprising a step of performing matching for outputting the target intermodulation signal on a signal that has passed through the skirt attenuation stage by a second matching attenuation stage.

11. In claim 10, In the step of receiving a dual fundamental wave and matching it with a fundamental wave matching network by a multi-filter coupling matching network-based intermodulation signal responder equipped in the above electronic device, the receiving antenna receives a first frequency signal and a second frequency signal as the dual fundamental wave signal, In the step of generating the nonlinear signal, the diode receives the first frequency signal and the second frequency signal and generates a target intermodulation signal, but generates a harmonic signal and a non-target intermodulation signal as signals other than the target during the generation process. A method for responding to an intermodulation signal based on a complex filter coupling matching network, wherein, in the step of outputting a target intermodulation signal by the complex filter coupling matching network, the complex filter coupling matching network outputs the target intermodulation signal by attenuating or filtering a dual fundamental signal, a harmonic signal, and an intermodulation signal other than the target.

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