A non-reciprocal electromagnetic protection system controlled based on the diode conductance modulation effect

Abstract

The present invention discloses a non-reciprocal electromagnetic protection system controlled based on the diode conductance modulation effect. The multi-port transmission module is used to distinguish the flow direction of radio frequency signals. The energy entering from the first type of radio frequency port is shunted in the module. Part of it flows out from the second type of radio frequency port, and the other part of the energy flows out from the control port to reach the control module. While the energy entering from the second type of radio frequency port will only flow out from the first type of radio frequency port. When the radio frequency signal is input from the first type of radio frequency port, when the control module receives the energy from the first type of radio frequency port, it inhibits the diode conductance modulation. When the radio frequency signal is input from the second type of radio frequency port, the control module does not receive energy and does not inhibit the diode conductance modulation. The present invention adopts non-reciprocal technology to protect both the receiving and transmitting channels simultaneously without interfering with normal transmission, and has a simple structure and is easy to integrate.

Description

Technical Field

[0001] The present invention relates to the technical field of strong electromagnetic protection, and particularly to a non-reciprocal electromagnetic protection system controlled based on the diode conductance modulation effect. Background Art

[0002] Ultra-wideband radio frequency systems have been widely used in fields such as radar, electronic reconnaissance, and spectrum detection. However, when facing strong electromagnetic attacks such as high-power microwaves, they exhibit higher sensitivity and vulnerability. Adaptive protection means such as limiters, energy selective surfaces, and energy selective antennas can effectively improve the robustness of ultra-wideband radio frequency systems against strong electromagnetic attacks. However, these protection means are reciprocal and will control the power of the radio frequency signal within a given threshold, limiting its transmission power while protecting the ultra-wideband radio frequency system.

[0003] Currently, there are very few existing non-reciprocal radio frequency transmission systems designed for the purpose of strong electromagnetic protection, and they need to be improved in terms of weight and complexity, unable to meet the development trend of miniaturization and easy integration of radio frequency systems. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a non-reciprocal electromagnetic protection system controlled based on the diode conductance modulation effect. By using non-reciprocal technology, it can protect both the receiving and transmitting channels without interfering with normal transmission, and has a simple structure and is easy to integrate.

[0005] The purpose of the present invention is achieved through the following technical solutions: A non-reciprocal electromagnetic protection system controlled based on the diode conductance modulation effect, comprising a multi-port transmission module, at least one first type of radio frequency port, and at least one second type of radio frequency port;

[0006] The multi-port transmission module is respectively connected to the first type of radio frequency port and the second type of radio frequency port, and the multi-port transmission module is further provided with at least one control port, and each control port is connected to a control module;

[0007] The multi-port transmission module is connected to each second type of radio frequency port through a radio frequency transmission line, and a transmission line reference ground wire is provided; A plurality of diodes are connected in parallel between the radio frequency transmission line and the transmission line reference ground wire, the anode of each diode is connected to the radio frequency transmission line, and the cathode of each diode is connected to the transmission line reference ground wire;

[0008] The multi-port transmission module is used to distinguish the flow direction of radio frequency signals and split the signals. The energy entering from the first type of radio frequency port is split in the module. Part of it flows out from the second type of radio frequency port, and the other part of the energy flows out from the control port to reach the control module; while the energy entering from the second type of radio frequency port will only flow out from the first type of radio frequency port.

[0009] The control module is used to suppress the conductance modulation of the diode connected on the radio frequency transmission line between the multi-port transmission module and the second type of radio frequency port when receiving the energy flowing out from the control port.

[0010] Preferably, the control module has a corresponding relationship with the second type of radio frequency port, and the corresponding relationship includes any one of the following two situations:

[0011] First, the number of the control modules is the same as that of the second type of radio frequency ports and they are in one-to-one correspondence. When the control module receives the energy flowing out from the control port, it suppresses the conductance modulation of the diode connected on the radio frequency transmission line between the multi-port transmission module and the second type of radio frequency port corresponding to this control module.

[0012] Second, the number of control modules is less than the number of the second type of radio frequency ports, that is, each control module corresponds to one or more different second type of radio frequency ports; when the control module receives the energy flowing out from the control port, it suppresses the conductance modulation of the diode connected on the radio frequency transmission line between the multi-port transmission module and the second type of radio frequency port corresponding to this control module.

[0013] Preferably, when the diode is in a high impedance state, the system is in a normal working mode; when the diode works in a low impedance state, the system is in a protection mode; the diode will automatically switch between the high impedance state and the low impedance state according to the input radio frequency energy, so as to realize the adaptive protection of the system.

[0014] Preferably, when the radio frequency signal is input from the first type of radio frequency port, when the control module suppresses the conductance modulation of the diode, the diode will not adaptively enter the low impedance state, and the signal is allowed to flow out from the second type of radio frequency port without loss. The suppression methods include:

[0015] By controlling the disconnection of the direct current path outside the diode, the direct current conductance modulation of the diode under radio frequency excitation is further suppressed.

[0016] Preferably, when the radio frequency signal is input from the second type of radio frequency port, the control module will not receive energy and will not suppress the conductance modulation of the diode. At this time, the diode will adaptively enter the low impedance state and enter the protection mode.

[0017] The beneficial effects of the present invention are as follows: (1) It provides adaptive protection against strong electromagnetic attacks, that is, without external bias or excitation, it has a fast response speed and the potential to counter nanosecond or sub-nanosecond pulses.

[0018] (2) It adopts non-reciprocal technology to protect both the receiving and transmitting channels simultaneously without interfering with normal transmission.

[0019] (3) The technology can operate in a wideband or even ultra-wideband.

[0020] (4) The technology has a low spatial overhead cost and is convenient for integration with other systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic diagram of the principle of the present invention;

[0022] Figure 2 is a schematic diagram of the control method of the diode;

[0023] Figure 3 is a schematic diagram of the first embodiment of the multi-port transmission module;

[0024] Figure 4 is a schematic diagram of the second embodiment of the multi-port transmission module;

[0025] Figure 5 is a schematic diagram of the third embodiment of the multi-port transmission module;

[0026] Figure 6 is a schematic diagram of the structure of a ultra-wideband non-reciprocal adaptive electromagnetic protection antenna assembly 10 provided by the present invention;

[0027] Figure 7 is a simulation diagram of the voltage standing wave ratio of a ultra-wideband non-reciprocal adaptive electromagnetic protection antenna assembly 10 provided by the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] The technical solutions of the present invention will be further described in detail below with reference to the drawings, but the protection scope of the present invention is not limited to the following.

[0029] As Figure 1As shown, the figure shows a topology diagram of an ultra-wideband non-reciprocal adaptive strong electromagnetic protection system controlled based on the diode conductance modulation effect, mainly including a multi-port transmission module, a control module, and diodes. The system is only connected to the outside world through X radio frequency ports, and these radio frequency ports are divided into the first type of radio frequency ports and the second type of radio frequency ports according to whether they allow the entry of large-amplitude signals. These radio frequency ports are all connected to the multi-port transmission module inside the system, and the diodes are loaded on the radio frequency transmission lines from the multi-port transmission module inside the system to the second type of radio frequency ports outside the system. In addition to the ports leading to the outside of the system, the multi-port transmission module also has some ports that only exist inside the system, including Y control ports for connecting the control module, and Z (which can be 0) loading ports for loading components such as resistors, capacitors, and inductors.

[0030] In the topology, the multi-port transmission module is the core. Except for the first type of radio frequency ports and the second type of radio frequency ports extending outside the system, other ports are all internal ports of the system. The power entering the system from the first type of radio frequency ports flows out from one or more second type of radio frequency ports, and notifies the control module to disconnect the direct current path (or directly apply a reverse bias DC voltage on both sides of the diode) of the diode D ij (i = 1, 2,...; j = 1, 2,...) outside the system, allowing the signal to flow out of the second type of radio frequency ports without loss. The energy entering the system from the second type of radio frequency ports will not notify the control module, and the diode D ij (i = 1, 2,...; j = 1, 2,...) limits the magnitude of the entering power. The inside of the multi-port transmission module is all passive metal structures and dielectric structures, and the resistors R i (i = 1, 2,...), capacitors C i (i = 1, 2,...), and inductors L i (i = 1, 2,...) are used to assist and cooperate with the passive structures inside the multi-port transmission module to achieve the above functions.

[0031] The principle of the present invention is as follows: When a diode is used as a radio frequency switch, it usually has two operating states, namely the high-impedance state and the low-impedance state. Different distributions of carriers in the diode will determine which operating state it is in. The distribution of carriers is affected by many factors. The method of controlling the impedance (conductance) of the diode by controlling the carrier distribution is called the conductance modulation of the diode. Usually, we use an external power supply to conduct conductance modulation on the diode. According to the different operating frequencies of the external power supply, it can be divided into direct current conductance modulation and alternating current conductance modulation (or called radio frequency conductance modulation). Among these two conductance modulation methods, the efficiency of direct current conductance modulation is higher, that is, the direct current source can make the diode enter the low-impedance state at a smaller original power. When there is a direct current path outside the diode, direct current conductance modulation always occurs accompanied by radio frequency conductance modulation, allowing the diode to enter the low-impedance state with a lower power threshold.

[0032] The diode connected in parallel to the radio frequency transmission line will affect the insertion loss of this section of the radio frequency transmission line. When the diode is in the high-impedance state, the insertion loss introduced by loading the diode is extremely small, and the system is in the normal operating mode. When the diode is in the low-impedance state, the insertion loss brought by diode loading is extremely large, and the system is in the protection mode. The diode will automatically switch between the high-impedance state and the low-impedance state according to the magnitude of the input radio frequency energy, so as to achieve the adaptive protection of the system.

[0033] The multi-port transmission module is used to distinguish the direction of signal power flow. The energy entering from the first type of radio frequency port is shunted in the module. Most of the energy flows out from the second type of radio frequency port, and a very small part of the energy flows out from the control end to reach the control module; while the energy entering from the second type of radio frequency port will only flow out from the first type of radio frequency port, and theoretically no energy will flow out from the control end to reach the control module. The lumped elements on the loading port will assist the multi-port transmission module to complete the above functions (for example, the multi-port transmission module is implemented according to the power divider architecture). In fact, these elements are not necessary (for example, the multi-port transmission module is implemented according to the coupler architecture).

[0034] The control module will control the diode according to the energy output from the control port. The control depends on the direct current path between the diode and the control module. Specifically, the control method is as follows Figure 2 As shown, the radio frequency transmission line and the transmission line reference ground wire are sequentially connected through an inductor and a switch, so as to form a direct current path outside the diode. The on-off control of the direct current path outside the diode is realized by controlling the on-off of the switch; when the direct current path outside the diode is disconnected, the direct current conductance modulation of the diode under radio frequency excitation is inhibited, so that the diode will not adaptively enter the low-impedance state, and the signal is allowed to flow out from the second type of radio frequency port without loss;

[0035] The radio frequency energy entering from the first type of radio frequency port will enter / activate the control module, thereby suppressing the diode conductance modulation, and the diode will not adaptively enter the low-resistance state. The radio frequency energy entering from the second type of radio frequency port will not enter / activate the control module, the conductance modulation of the diode is not suppressed, and it still has the ability to adaptively enter the low-resistance state.

[0036] In the embodiments of the present application, the multi-port transmission module is essentially a signal splitting device that can distinguish the signal flow direction. Generally, devices such as power dividers or couplers can be used to achieve this. This patent does not restrict the implementation method. For example, it allows the multi-port transmission module to adopt a pure passive structure, and also allows active modules such as amplifier modules to be added thereto.

[0037] As Figure 3 shown, in the first embodiment, the multi-port transmission module adopts a power divider architecture. In this embodiment, for simplicity of description and to highlight the principle, only a one-to-three power division architecture is used for illustration. In this embodiment, the multi-port transmission module has a first type of radio frequency port, two second type of radio frequency ports, and a control port. Generally, the multi-port transmission module adopting a power division architecture can be divided into two parts: (1) a splitting junction, which connects one end of the transmission lines together to form a circuit with multiple ports and signal splitting ability; (2) an isolation network, which is usually assumed to be between the second type of radio frequency port and the control port, and is used to cancel the energy flowing from the second type of radio frequency port to the control port in the splitting junction, so as to achieve isolation between the second type of radio frequency port and the control port. In this embodiment, a cross-shaped power division junction is formed by four transmission lines, and a decoupling network is jointly formed by capacitors C1, C2, resistor R1, and a grounded transmission line.

[0038] As Figure 4 shown, in the second embodiment, the multi-port transmission module is implemented by adopting a coupler architecture. In this embodiment, for simplicity of description and to highlight the principle, only a six-port coupling architecture is used for illustration. In this embodiment, the multi-port transmission module has two first type of radio frequency ports, two second type of radio frequency ports, and two control ports. In this embodiment, the multi-port transmission module adopts a coupling network to distinguish the signal flow direction and complete signal splitting. In this embodiment, a coupler in the form of a branch line is used, and the two transmission line output joints in the middle are combined into one path to drive the control module, and an isolation resistor R1 is introduced to ensure that the energy of the two transmission lines in the middle will only flow to the control port. The radio frequency energy flowing in from any one of the first type of radio frequency ports will flow out from the two second type of radio frequency ports and the control port.

[0039] As Figure 5As shown, in the third embodiment, the multi-port transmission module is implemented by an active circuit. For simplicity of explanation and highlighting the principle in this embodiment, only a four-port coupling architecture is used for illustration. In this embodiment, the multi-port transmission module has a first type of RF port, a second type of RF port, and a control port. In this example, transistors Q1-Q3 not only amplify the signal but also distinguish the signal flow direction. Resistors R1-R9 are used to set the quiescent operating points for the transistors, and the circulator is used for port isolation.

[0040] The control module is usually implemented by a rectifier, but any device that can complete RF energy detection and control the conductance modulation of the diode through a DC path is allowed, such as a combination of a detector and an FPGA. For the controlled switch that controls the on / off of the DC path, MOSFET, MESE devices, etc. can be used, and this patent does not restrict the implementation method.

[0041] The diode subjected to conductance modulation usually uses a PIN diode, and this patent does not restrict the implementation method. For example, using a varactor diode is also within the protection scope.

[0042] This patent protects the topology structure that selectively suppresses the conductance modulation of the diode according to different signal flow directions after distinguishing the signal flow direction. This structure allows the electromagnetic protection system to extend the protection to the transmission link.

[0043] In the embodiment of this application, taking the combination of the system of this application and a Vivaldi antenna as an example, specifically, please refer to Figure 6 , Figure 6 This is a ultra-wideband non-reciprocal adaptive electromagnetic protection antenna assembly 10 provided by the embodiment of the present invention, including an antenna unit 101, a multi-port transmission module 102, a microstrip-to-slotline balun 103, a control module 104, and an electronic control switch 105. All resistors, capacitors, inductors, diodes, and electronic control switch components are installed using surface mount technology in this example, but are not shown in Figure 6 . Figure 6Only the metal structures and dielectric substrates in the above-mentioned ultra-wideband non-reciprocal adaptive electromagnetic protection antenna assembly are shown. The metal structures in the above-mentioned ultra-wideband non-reciprocal adaptive electromagnetic protection antenna assembly are fabricated on two surfaces of a dielectric substrate, and the metal structures on the two surfaces are connected by metallized vias. In the above-mentioned ultra-wideband non-reciprocal adaptive electromagnetic protection antenna assembly, except for the microstrip-to-slotline balun 103, the rest of the RF components are implemented by microstrip lines. In this example, the multi-port transmission module 102 includes a total of N = 9 ports. Among them, the number of ports X for transmitting RF energy is 2, the number of the first type of RF ports P is 1, and this port is connected to the edge of the dielectric substrate through a microstrip line; the number of the second type of RF ports Q is 1, and this port is connected to the microstrip-to-slotline balun 103 through a microstrip line; the number of ports Y connected to the control module is 1, and this port is connected to the control module 104 through a microstrip line; the remaining 6 ports are used to load capacitors and resistors (the number of inductors loaded is 0 in this example), and these ports are distributed between the microstrip line connecting the second type of RF port and the microstrip line connecting the control terminal. All capacitors and resistors are installed in a bridging manner in this example (that is, both ends of the component are always connected to two ports, but not to the ground of any port); the microstrip-to-slotline balun 103 is connected to the antenna element 101 through a slotline. In this example, the antenna element 101 uses a Vivaldi antenna; the number of diodes is 1 in this example, and they are installed in parallel on the slotline between the balun 103 and the antenna 101, and a DC loop is formed between the two metal sheets in the Vivaldi antenna and the electronic control switch 105; the on / off of the electronic control switch 105 is controlled by the control module 104.

[0044] Among them, Figure 6 The structure shown is an example, and the present invention does not limit the specific implementation.

[0045] It can be seen that the present invention has the characteristics of simple structure, small size and high integration degree in the implementation process. Compared with the antenna operating in the S-band to C-band in this example, the additional space overhead is negligible.

[0046] Figure 7 It is the VSWR curve graph of the standing wave ratio simulated for an ultra-wideband non-reciprocal adaptive electromagnetic protection antenna assembly 10 provided by an embodiment of the present invention. As shown in the figure, when the standing wave ratio VSWR is less than 2, the assembly 10 can cover the operating frequency range of 2 GHz - 6 GHz, has an impedance bandwidth of 1:3, and the operating frequency band involves the S-band to C-band.

[0047] For the measured maximum received power, maximum transmitted power, non-reciprocity and protection level of an ultra-wideband non-reciprocal adaptive electromagnetic protection antenna assembly 10 provided by an embodiment of the present invention. As shown in the following table:

[0048] Frequency (GHz) 2 3 4 5 6 Maximum received power (W) 0.2 0.1 0.1 0.2 0.1 Maximum transmitted power (W) 21.9 12.9 15.8 17 21.4 Non-reciprocity (dB) 20.9 21 22.2 20.4 24.6 Protection level (dB) 31.1 24.4 27.6 22.8 20.7

[0049] The component 10 can achieve a transmission power of more than 20W, enter the protection mode when receiving energy in the order of hundreds of milliwatts, and provide an isolation of more than 20dB (protection level) in the full frequency band in the protection mode. The component 10 exhibits a maximum non-reciprocity of 24.6dB. The design here is only an example, and the present invention is not limited thereto.

[0050] The above is only the specific implementation manner of this application, but the protection scope of this application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in this application should be covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

1. A non-reciprocal electromagnetic protection system based on diode conductivity modulation effect control, characterized in that: comprising a multi-port transmission module, at least one first type radio frequency port and at least one second type radio frequency port; The multi-port transmission module is connected to the first type of radio frequency port and the second type of radio frequency port respectively, and the multi-port transmission module is also provided with at least one control port, and each control port is connected to a control module; The multi-port transmission module is connected to each second-class radio frequency port through a radio frequency transmission line, and a transmission line reference ground line is provided; a plurality of diodes are provided in parallel between the radio frequency transmission line and the transmission line reference ground line, an anode of each diode is connected to the radio frequency transmission line, and a cathode of each diode is connected to the transmission line reference ground line; The multi-port transmission module is used to distinguish the flow direction of the RF signal and perform signal diversion. The energy entering from the first type of RF port is diverted in the module, a part of the energy flows out from the second type of RF port, and the other part of the energy flows out from the control port to the control module; while the energy entering from the second type of RF port flows out from the first type of RF port; The multi-port transmission module adopts a power divider architecture and has a first-class RF port, two second-class RF ports and a control port. The multi-port transmission module adopting the power divider architecture can be divided into two parts: (1) a shunt junction, which connects one end of the transmission line together to form a circuit with multiple ports and signal shunt capability; (2) an isolation network, which is between the second-class RF port and the control port and is used to cancel the energy flowing from the second-class RF port to the control port in the shunt junction, so as to achieve isolation between the second-class RF port and the control port. The control module is used to suppress the conductance modulation of the diode connected to the radio frequency transmission line between the multi-port transmission module and the second type of radio frequency port when receiving the energy flowing out of the control port; When the RF signal is input from the first type RF port, when the control module suppresses the diode conductivity modulation, the diode will not adaptively enter the low resistance state, allowing the signal to flow out of the second type RF port without loss, and the suppression method includes: By controlling the DC path outside the diode to be disconnected, the DC conductivity modulation of the diode under RF excitation is suppressed; When the RF signal is input from the second type RF port, the control module will not receive energy and will not suppress the diode conductivity modulation. At this time, the diode will adaptively enter a low resistance state and enter a protection mode.

2. The non-reciprocal electromagnetic protection system based on diode conductivity modulation effect control according to claim 1, characterized in that: The control module has a corresponding relationship with the second type of radio frequency port, and the corresponding relationship includes any one of the following two situations: First, the control module has the same number as the second type of RF port and corresponds one to one. When the control module receives energy flowing out of the control port, the conductance modulation of the diode connected to the RF transmission line between the multi-port transmission module and the second type of RF port corresponding to the control module is suppressed; Second, the number of control modules is less than the number of second-class RF ports, that is, each control module corresponds to one or more different second-class RF ports; when the control module receives energy flowing out from the control port, the conductance modulation of the diode connected on the RF transmission line between the multi-port transmission module and the second-class RF port corresponding to the control module is suppressed.

3. The non-reciprocal electromagnetic protection system based on diode conductivity modulation effect control according to claim 1, characterized in that: When the diode is in a high-resistance state, the system is in a normal working mode; when the diode is in a low-resistance state, the system is in a protection mode; the diode will automatically switch between the high-resistance state and the low-resistance state according to the input RF energy, thereby realizing adaptive protection of the system.

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