Switching type non-reciprocal protection circuit and communication equipment

Abstract

The present application relates to a switch-type non-reciprocal protection circuit and communication equipment, which includes a first port circuit, a directional coupler, a protection module, a detection module, a switch module, and a second port circuit. The directional coupler is used to couple the path signal to the detection module, the detection module is used to convert the coupled signal into a detection voltage, the switch module is used to control the protection module to start working when the detection voltage is greater than the switch conduction voltage, and to control the protection module not to start working when the detection voltage is less than the switch conduction voltage, and the protection module is used to limit the path signal that exceeds the starting level when starting working; the coupled signal includes a received signal or a transmitted signal, and the signal power of the received signal is greater than the signal power of the transmitted signal. The circuit complexity of the non-reciprocal protection circuit is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of radio frequency circuits and relates to a switch-type non-reciprocal protection circuit and communication equipment. Background Art

[0002] As an adaptive power-control protection device, limiters are widely used in electromagnetic protection. Currently, limiters are the primary electromagnetic protection component in existing RF front-ends. Their mechanism of operation is as follows: when the input signal power is below the threshold level, the signal passes normally. When the input signal exceeds the threshold level, the limiter limits the output signal to a certain range, thereby protecting subsequent circuits from damage caused by high-power electromagnetic waves. As transceiver switches become increasingly miniaturized and integrated, higher requirements are placed on power handling performance.

[0003] Typically, a limiter is connected before the low-noise amplifier of the T / R assembly to protect the low-noise amplifier and receiver from being burned by high-power signals received from the air or high-power signals leaked from the transmitter. For radar communication equipment with integrated transceiver antennas, radar transmission and reception are mainly achieved through a transceiver switch or a circulator; for radar communication equipment with separate transceivers, the radar transceiver antennas are connected to the transmitter and receiver respectively through feeders. When the radar is attacked by a strong electromagnetic attack, the strong electromagnetic signal directly enters the system through antenna coupling, causing damage to the transceiver switch and transmitter, such as causing the static operating point of the transmitter to shift, causing the transmitter performance to deteriorate, and even burning the transmitter and transceiver switch. Therefore, electromagnetic protection is required for the transmitter and transceiver switch. Current research on non-reciprocal protection circuits mainly adopts the combination of directional couplers and detectors. However, in the process of realizing the present invention, the inventors found that the traditional non-reciprocal protection circuit technology still has the technical problem of high circuit complexity. Summary of the Invention

[0004] In response to the problems existing in the above-mentioned traditional methods, the present invention proposes a switch-type non-reciprocal protection circuit and a communication device, which can effectively reduce the circuit complexity of the non-reciprocal protection circuit.

[0005] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0006] In one aspect, a switch-type non-reciprocal protection circuit is provided, comprising a first port circuit, a directional coupler, a protection module, a detection module, a switch module, and a second port circuit;

[0007] The first end of the directional coupler is connected to the first port circuit, the second end of the directional coupler is connected to the first end of the protection module, the third end of the directional coupler is connected to the first end of the detection module, and the fourth end of the directional coupler is grounded; the second end of the protection module is connected to the second port circuit, the third end of the protection module is connected to the second end of the switch module, the second end of the detection module is connected to the first end of the switch module, and the third end of the switch module is grounded. The first port circuit is used to connect to the front-end feeder, and the second port circuit is used to connect to the rear-end feeder.

[0008] The directional coupler is used to couple the path signal to the detection module, the detection module is used to convert the coupled signal into a detection voltage, the switch module is used to control the protection module to start working when the detection voltage is greater than the switch on-voltage, and to control the protection module not to start working when the detection voltage is less than the switch on-voltage. The protection module is used to limit the path signal that exceeds the limit level when starting; the coupled signal includes a received signal or a transmitted signal, and the signal power of the received signal is greater than the signal power of the transmitted signal.

[0009] In one embodiment, the directional coupler includes a parallel line directional coupler, a branch line directional coupler, or a Lange directional coupler.

[0010] In one embodiment, the first port circuit includes an SMA type connector, an N type connector, a TNC type connector, a BNC type connector, or an SSMA type connector.

[0011] In one embodiment, the second port circuit includes an SMA type connector, an N type connector, a TNC type connector, a BNC type connector, or an SSMA type connector.

[0012] In one embodiment, the switch module includes a transistor or a field effect transistor.

[0013] In one embodiment, the detection module includes a Walton voltage doubler rectifier module or a Dickson voltage doubler rectifier module.

[0014] In one embodiment, the protection module includes a first capacitor, a second capacitor, a first inductor and a limiting unit, one end of the first capacitor is connected to the second end of the directional coupler, the other end of the first capacitor is respectively connected to one end of the second capacitor, one end of the first inductor and the anode of the limiting unit, the other end of the second capacitor is connected to the second port circuit, the other end of the first inductor is grounded, and the cathode of the limiting unit is connected to the second end of the switch module.

[0015] In one embodiment, the limiter unit includes a first PIN diode, a second PIN diode, and a third PIN diode connected in series, the switch module is a field effect transistor, the detection module includes a third capacitor, a fourth capacitor, a second inductor, a first Schottky diode and a second Schottky diode, and the directional coupler includes a parallel line directional coupler and a resistor;

[0016] The anode of the first PIN diode is connected to one end of the first inductor, the cathode of the third PIN diode is connected to the drain of the field effect transistor, the source of the field effect transistor is grounded, the gate of the field effect transistor is connected to one end of the second inductor, the other end of the second inductor is respectively connected to the cathode of the second Schottky diode and one end of the fourth capacitor, the other end of the fourth capacitor is grounded, the anode of the second Schottky diode is respectively connected to the cathode of the first Schottky diode and one end of the third capacitor, the anode of the first Schottky diode is grounded, the other end of the third capacitor is connected to the third end of the parallel line directional coupler, the fourth end of the parallel line directional coupler is grounded through a resistor, the second end of the parallel line directional coupler is connected to one end of the first capacitor, and the first end of the parallel line directional coupler is connected to the first port circuit.

[0017] On the other hand, a communication device is also provided, including a dielectric substrate and the above-mentioned switch-type non-reciprocal protection circuit, wherein the dielectric substrate is used to carry the switch-type non-reciprocal protection circuit.

[0018] In one embodiment, the dielectric substrate includes an FR4 substrate, an F4B substrate, a Rogers substrate, a GaAs substrate, a GaN substrate, an aluminum oxide substrate, an aluminum nitride substrate, or a sapphire substrate.

[0019] One of the above technical solutions has the following advantages and beneficial effects:

[0020] The switch-type non-reciprocal protection circuit and communication device are designed to have non-reciprocal protection circuitry by using a first port circuit, a directional coupler, a protection module, a detection module, a switch module, and a second port circuit. When a signal is input from the first port circuit, that is, when receiving an external electromagnetic signal from the antenna end, the signal enters the path formed by the first port circuit, the directional coupler, the protection module, and the second port circuit. At this time, most of the power of the path signal is input to the protection module via the directional coupler, and a small portion of the power is passed to the detection module via the directional coupler. The detection module converts the coupled signal input from the directional coupler into a detection voltage and passes it to the switch module. When the detection voltage is less than the switch-on voltage of the switch module, the switch module is disconnected, the protection module does not operate, and the path signal can pass normally. Conversely, the switch module is turned on, and the protection module operates normally. At this time, if the power of the path signal reaching the protection module via the directional coupler is greater than or equal to the protection module's threshold level, the path signal will be limited and output by the protection module. At this time, if the power of the path signal reaching the protection module via the directional coupler is less than the protection module's threshold level, the path signal can still pass normally and be sent to the rear feeder via the second port circuit.

[0021] When a signal is input from the second-port circuit—that is, during the transmission of the electromagnetic signal to be transmitted—the signal enters the path formed by the second-port circuit, the protection module, the directional coupler, and the first-port circuit. Due to the directional coupler's superior directionality, the signal power coupled to the detection module via the directional coupler is lower than the signal power coupled during signal reception, resulting in a lower detection voltage. The switch module remains disconnected, the protection module is inoperative, and the path signal can pass normally and be sent to the front-end feeder via the first-port circuit for transmission to the antenna. This creates a switching limiter for the received signal, while the transmitted signal remains unlimited. This achieves efficient bidirectional nonreciprocal limiting with a simpler circuit structure, thereby reducing the circuit complexity of the nonreciprocal protection circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 Schematic diagram of the structure of a switch-type non-reciprocal protection circuit in one embodiment;

[0024] Figure 2 A schematic structural diagram of a switch-type non-reciprocal protection circuit in another embodiment;

[0025] Figure 3 FIG. 1 is a schematic diagram of a bidirectional input and output power curve of a switch-type non-reciprocal protection circuit in an embodiment. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0028] It should be noted that reference to an "embodiment" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present invention. The appearance of such a phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0029] Those skilled in the art will appreciate that the embodiments described herein may be combined with other embodiments. The term "and / or" used in the present specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0030] Traditional limiters without nonreciprocity generally lack directionality. For single-stage limiters, limiting performance remains essentially the same for both input and output signals. Multi-stage limiters, on the other hand, typically require unidirectional input and output, often due to optimized limiting structures in the preceding stages to increase power handling. Therefore, when using these existing limiters to protect transmitters and transceiver switches, they also limit the transmitted signal.

[0031] Current research on nonreciprocal protection circuits primarily utilizes a combination of a directional coupler and a detector. This circuit uses a detection voltage to bias a PIN diode. The higher the detection voltage, the lower the PIN diode's threshold voltage. Because directional couplers are directional, the detection voltages output by the directional coupler and detector differ when transmitting and receiving signals, resulting in different threshold voltages for the PIN diode.

[0032] The switch-type non-reciprocal protection circuit solution designed in this application is a non-reciprocal limiter with different threshold levels for transmit and receive signals. It can be used in radar communication paths that share both transmit and receive signals to protect the transceiver switch, or in radar communication paths where both transmit and receive signals are separated to protect the transmitter. For example, it can be directly connected between the transmitting antenna and the transmitter, or between the transmitting and receiving antennas and the transceiver switch. During forward input (transmission), the threshold level is high, requiring it to be higher than the transmitter's transmit power. During reverse input (reception), the threshold level is low, requiring the output threshold level to be lower than the withstand power of the transmitter or transceiver switch. This achieves bidirectional non-reciprocal limiting and effectively protects the transmitter or transceiver switch.

[0033] The following describes the embodiments of the present invention in detail with reference to the accompanying drawings.

[0034] See also Figure 1In one embodiment, the present application provides a switch-type non-reciprocal protection circuit 100, comprising a first port circuit 01, a directional coupler 10, a protection module 20, a detection module 30, a switch module 40, and a second port circuit 02. A first end 101 of the directional coupler 10 is connected to the first port circuit 01, a second end 102 of the directional coupler 10 is connected to the first end 201 of the protection module 20, a third end 103 of the directional coupler 10 is connected to the first end 301 of the detection module 30, and a fourth end 104 of the directional coupler 10 is grounded. A second end 202 of the protection module 20 is connected to the second port circuit 02, and a third end 203 of the protection module 20 is connected to the second end 402 of the switch module 40. A second end 302 of the detection module 30 is connected to the first end 401 of the switch module 40, and a third end 403 of the switch module 40 is grounded.

[0035] The first port circuit 01 is used to connect to the front-end feeder, and the second port circuit 02 is used to connect to the back-end feeder. The directional coupler 10 is used to couple the path signal to the detection module 30. The detection module 30 is used to convert the coupled signal into a detection voltage. The switch module 40 is used to control the protection module 20 to start working when the detection voltage is greater than the switch conduction voltage, and to control the protection module 20 to stop working when the detection voltage is less than the switch conduction voltage. The protection module 20 is used to limit the path signal that exceeds the threshold level when it is started. The coupled signal includes a received signal or a transmitted signal, and the signal power of the received signal is greater than the signal power of the transmitted signal.

[0036] It can be understood that in this design, the switch-type non-reciprocal protection circuit 100 is applied to a common transmission and reception path to protect the transceiver switch, and can also be applied to a path with separate transmission and reception to protect the transmitter. The first port circuit 01 is the input / output port connected to the front-end feeder. For electronic equipment such as radars with integrated transmission and reception, the first port circuit 01 is usually connected to the transceiver antenna via a feeder (called the front-end feeder). For electronic equipment such as radars with separate transmission and reception, the first port circuit 01 is usually connected to the transmitting antenna via a feeder (called the front-end feeder). The second port circuit 02 is the input / output port connected to the rear-end feeder. For electronic equipment such as radars with integrated transmission and reception, the second port circuit 02 is usually connected to the transceiver switch via a feeder (called the rear-end feeder). For electronic equipment such as radars with separate transmission and reception, the second port circuit 02 is usually connected to the transmitter via a feeder (called the rear-end feeder).

[0037] The function of the directional coupler 10 is to couple some energy from the path and send it to the detection module 30 for detection. When the signal enters the switch-type non-reciprocal protection circuit 100 from the first port circuit 01, the third end 103 of the directional coupler 10 serves as the coupling port of the directional coupler 10. At this time, the signal power input from the directional coupler 10 to the detection module 30 is relatively large. At this time, the logarithm of the ratio of the output power of the third end 103 of the directional coupler 10 to the input power of the first end 101 of the directional coupler 10 is recorded as the coupling degree C.

[0038] When the signal enters the switch-type non-reciprocal protection circuit 100 from the second port circuit 02, the third end 103 of the directional coupler 10 is the isolation port of the directional coupler 10. At this time, the signal power input from the directional coupler 10 to the detection module 30 is relatively small. At this time, the logarithm of the ratio of the output power of the third end 103 of the directional coupler 10 to the input power of the second end 102 of the directional coupler 10 is recorded as the isolation I. The difference between the coupling degree C and the isolation I is usually recorded as the directivity D. The directional coupler 10 is required to have good directivity, usually above 8dB; and is required to have a low coupling degree, usually below -7dB, to prevent excessive insertion loss of the limiter. The directivity of the directional coupler 10 can be improved by using a serrated structure on the microstrip coupling edge, introducing compensation technology of inductance and / or capacitance elements, and loading a short stub at the coupling end.

[0039] The function of protection module 20 is to limit path signals exceeding its threshold voltage during startup (or normal operation). Protection module 20 can be composed of multiple threshold voltage units, connected by transmission lines. Each threshold voltage unit can be composed of the same type of PIN diodes connected in series. In practical applications, PIN diodes with higher threshold voltages are preferred for the required threshold voltage units.

[0040] The function of the detection module 30 is to detect a DC voltage based on the coupled signal from the path signal. This DC voltage is called the detection voltage, and is used to control the conduction or disconnection of the switch module 40 accordingly. When a signal enters the switch-type non-reciprocal protection circuit 100 from the first port circuit 01, the path signal transmitted within the transmission path formed by the first port circuit 01, the directional coupler 10, the protection module 20, and the second port circuit 02 in the switch-type non-reciprocal protection circuit 100 is the received signal input from the antenna end. In this case, the coupled signal coupled to the detection module 30 is also referred to as the received signal. When a signal enters the switch-type non-reciprocal protection circuit 100 from the second port circuit 02, the path signal transmitted within the transmission path formed by the first port circuit 01, the directional coupler 10, the protection module 20, and the second port circuit 02 in the switch-type non-reciprocal protection circuit 100 is the signal to be transmitted from the transceiver switch / transmitter. In this case, the coupled signal coupled to the detection module 30 is also referred to as the transmitted signal.

[0041] The switch module 40 switches between on and off states based on the comparison between the detection voltage and its own switch on-voltage, thereby controlling the operation of the protection module 20. When the switch module 40 is on, it exhibits a low-impedance state, allowing the protection module 20 to function normally and acting as a limiter for the signal path. When the switch module 40 is off, it exhibits a high-impedance state, disabling the protection module 20 and allowing the signal path to pass normally.

[0042] Specifically, when a signal is input into the path from the first port circuit 01, the path signal reaches the first terminal 101 of the directional coupler 10. Most of the path signal's power is then input to the first terminal 201 of the protection module 20 via the second terminal 102 of the directional coupler 10, while a small portion of the power is transmitted to the first terminal 301 of the detection module 30 via the third terminal 103 of the directional coupler 10. The detection module 30 detects the coupled signal input from the directional coupler 10 into a DC voltage and transmits it to the switch module 40. When the detection voltage is lower than the switch-on voltage of the switch module 40, the switch module 40 is disconnected, assuming a high-impedance state. The protection module 20 stops functioning, and the signal passes normally.

[0043] When the detection voltage is greater than the switch-on voltage of the switch module 40, the switch module 40 is turned on, presenting a low-impedance state, and the protection module 20 operates normally. (If the signal power reaching the protection module 20 via the directional coupler 10 is greater than or equal to the threshold level of the protection module 20, the protection module 20 immediately limits the amplitude of the signal at the moment the switch module 40 is turned on. If the signal power is less than the threshold level, the signal limiting function is performed after the signal power increases above the threshold level.) At this point, the switch-type non-reciprocal protection circuit 100 limits the amplitude of high-power signals greater than the threshold level of the protection module 20. At this point, the output level of the protection module 20 is lower than the withstand power of the transmitter or transceiver switch, thereby preventing damage to the transmitter or transceiver switch.

[0044] When a signal is input into the path from the second port circuit 02, it reaches the directional coupler 10 via the protection module 20. Due to the good directionality of the directional coupler 10, the signal power input from the third end 103 of the directional coupler 10 to the first end 301 of the detection module 30 is lower than when the signal is input from the first port circuit 01. Consequently, the signal power coupled from the directional coupler 10 to the detection module 30 is lower, and the detection voltage is also lower. At this point, the detection voltage is lower than the switch-on voltage of the switch module 40. The switch module 40 is disconnected, presenting a high-impedance state. The protection module 20 is deactivated, and the signal passes normally. The design ensures that the detection voltage remains lower than the switch-on voltage of the switch module 40 within the transmitter's transmission power, ensuring normal transmitter operation.

[0045] Therefore, when a signal is input (i.e., received) from the first port circuit 01, the switch-type non-reciprocal protection circuit 100 begins limiting only when the detection voltage is greater than the switch-on voltage of the switch module 40 and the signal power on the protection module 20 is greater than its threshold level. At this point, the signal level output from the second port circuit 02 is lower than the power tolerance of the transmitter or transceiver switch, effectively protecting the transmitter or transceiver switch. When a signal is input (i.e., transmitted) from the second port circuit 02, the detection voltage of the switch-type non-reciprocal protection circuit 100 is lower than the switch-on voltage of the switch module 40, causing the protection module 20 to fail to function properly, and thus the transmitted signal can pass normally.

[0046] In summary, when the detection voltage is less than the switch-on voltage of the switch module 40, both transmit and receive signals can pass normally. When the detection voltage is greater than the switch-on voltage of the switch module 40, a limiter acts on the received signal (the signal input from the first port circuit 01). However, the design of the transmit signal avoids this situation, so a switch-type limiter acts on the received signal, while no limiter acts on the transmit signal.

[0047] The above-mentioned switch-type non-reciprocal protection circuit 100 is designed to have a non-reciprocal protection circuit through the first port circuit 01, the directional coupler 10, the protection module 20, the detection module 30, the switch module 40 and the second port circuit 02. When the signal is input from the first port circuit 01, that is, in the process of receiving the external electromagnetic signal from the antenna end, the signal enters the path formed by the first port circuit 01, the directional coupler 10, the protection module 20 and the second port circuit 02. At this time, most of the power of the path signal is input to the protection module 20 through the directional coupler 10, and a small part of the power is passed through the directional coupler 10 to the detection module 30. The detection module 30 will input the signal from the directional coupler 10. The coupled signal is converted into a detection voltage and passed to the switch module 40. When the detection voltage is lower than the switch-on voltage of the switch module 40, the switch module 40 is disconnected, the protection module 20 does not operate, and the path signal can pass normally. Conversely, the switch module 40 is turned on, and the protection module 20 operates normally. At this time, if the power of the path signal reaching the protection module 20 via the directional coupler 10 is greater than or equal to the threshold level of the protection module 20, the path signal will be limited and output by the protection module 20. At this time, if the power of the path signal reaching the protection module 20 via the directional coupler 10 is lower than the threshold level of the protection module 20, the path signal can still pass normally and be sent to the rear-end feeder via the second port circuit 02.

[0048] When a signal is input from the second port circuit 02, that is, during the transmission of the electromagnetic signal to be transmitted, the signal enters the path formed by the second port circuit 02, the protection module 20, the directional coupler 10, and the first port circuit 01. Due to the good directionality of the directional coupler 10, the signal power coupled to the detection module 30 via the directional coupler 10 is smaller than the signal power coupled during the signal reception process, resulting in a smaller detection voltage. The switch module 40 remains disconnected, the protection module 20 does not operate, and the path signal can pass normally and be sent to the front-end feeder via the first port circuit 01 to the antenna for transmission. In this way, a switching limiter is formed for the received signal, while the transmitted signal is not limited. Compared with traditional non-reciprocal protection circuit technology, this circuit structure design is more simple and reliable, achieving efficient bidirectional non-reciprocal limiting, thereby achieving the purpose of reducing the circuit complexity of the non-reciprocal protection circuit.

[0049] In one embodiment, the directional coupler 10 includes a parallel line directional coupler 10, a branch line directional coupler 10, or a Lange directional coupler 10. Optionally, it can be, but is not limited to, any one of the parallel line directional coupler 10, the branch line directional coupler 10, and the Lange directional coupler 10, so that the required directivity can be provided through a relatively simple coupler structure.

[0050] In one embodiment, the first port circuit 01 includes an SMA connector, an N-type connector, a TNC connector, a BNC connector, or an SSMA connector. It is understood that the switch-type non-reciprocal protection circuit 100 can be fabricated on a dielectric substrate. Depending on the dielectric substrate, fabrication process, and performance requirements, the first port circuit 01 can be configured to utilize, but is not limited to, an SMA connector, an N-type connector, a TNC connector, a BNC connector, or an SSMA connector to provide the required front-end input / output port functionality.

[0051] In one embodiment, the second port circuit 02 includes an SMA connector, an N-type connector, a TNC connector, a BNC connector, or an SSMA connector. It is understood that, depending on requirements such as the dielectric substrate, processing technology, and performance indicators, the second port circuit 02 may also, but is not limited to, use any of the SMA connector, N-type connector, TNC connector, BNC connector, and SSMA connector to provide the required back-end input / output port functions.

[0052] In one embodiment, the switch module 40 includes a transistor or a field effect transistor. Preferably, a transistor or a field effect transistor can be used as the required switch module 40, thereby providing the required switching and control functions with a relatively simple circuit structure.

[0053] In one embodiment, the detection module 30 includes a Walton voltage-doubler rectifier module or a Dickson voltage-doubler rectifier module. It is understood that the detection module 30 can be a voltage-doubler detection module 30, such as a Walton voltage-doubler rectifier (detection) module or a Dickson voltage-doubler rectifier (detection) module, whose circuit is composed of Schottky diodes and capacitors connected in series and parallel. The number of Schottky diodes can be, but is not limited to, 1 to 6, thereby ensuring the required detection efficiency with a relatively simple circuit structure.

[0054] In one embodiment, Figure 2 As shown, the protection module 20 includes a first capacitor 211, a second capacitor 212, a first inductor 221, and a limiting unit. One end of the first capacitor 211 is connected to the second end 102 of the directional coupler 10. The other end of the first capacitor 211 is respectively connected to one end of the second capacitor 212, one end of the first inductor 221, and the anode of the limiting unit. The other end of the second capacitor 212 is connected to the second port circuit 02. The other end of the first inductor 221 is grounded. The cathode of the limiting unit is connected to the second end 402 of the switch module 40. The limiting unit is a unit circuit composed of PIN diodes, which can be composed of 1 to 9 PIN diodes of the same model connected in series. The specific selection can be based on the limiting needs.

[0055] It can be understood that in this embodiment, the protection module 20 specifically adopts a circuit structure of two capacitors, one inductor and one limiting unit, and the capacitance of the first capacitor 211 and the second capacitor 212 are the same. Through this circuit structure, the reliable and efficient implementation of the limiting function can be ensured.

[0056] In one embodiment, Figure 2 As shown, the limiting unit includes a first PIN diode 231, a second PIN diode 232, and a third PIN diode 233 connected in series. The switch module 40 is a field effect transistor 411. The detection module 30 includes a third capacitor 311, a fourth capacitor 312, a second inductor 321, a first Schottky diode 331, and a second Schottky diode 332. The directional coupler 10 includes a parallel line directional coupler 10 and a resistor 111.

[0057] The anode of the first PIN diode 231 is connected to one end of the first inductor 221, and the cathode of the third PIN diode 233 is connected to the drain 402 of the field-effect transistor 411. The source 403 of the field-effect transistor 411 is grounded, and the gate 401 of the field-effect transistor 411 is connected to one end of the second inductor 321. The other end of the second inductor 321 is respectively connected to the cathode of the second Schottky diode 332 and one end of the fourth capacitor 312. The other end of the fourth capacitor 312 is grounded. The anode of the second Schottky diode 332 is respectively connected to the cathode of the first Schottky diode 331 and one end of the third capacitor 311. The anode of the first Schottky diode 331 is grounded. The other end of the third capacitor 311 is connected to the third end of the parallel line directional coupler 10. The fourth end of the parallel line directional coupler 10 is grounded via the resistor 111. The second end of the parallel line directional coupler 10 is connected to one end of the first capacitor 211. The first end of the parallel line directional coupler 10 is connected to the first port circuit 01.

[0058] It will be understood that in this embodiment, the limiting unit of the protection module 20 includes three PIN diodes connected in series, and these PIN diodes are of the same model. The anode of the first PIN diode 231 is connected to the first inductor 221, the first capacitor 211, and the second capacitor 212 via transmission lines. The cathode of the first PIN diode 231 is connected to the anode of the second PIN diode 232. The cathode of the second PIN diode 232 is connected to the anode of the third PIN diode 233. The cathode of the third PIN diode 233 is connected to the drain 402 of the field-effect transistor 411. The field-effect transistor 411 can be an NMOS field-effect transistor, having a G port, a D port, and an S port. The G port is the first terminal 401 of the switch module 40, the D port is the second terminal 402 of the switch module 40, and the S port is the third terminal 403 of the switch module 40. The S port is grounded. The detection module 30 uses a Dickson voltage doubler rectifier module. Its third capacitor 311 and fourth capacitor 312 have the same capacitance value, and the first Schottky diode 331 and the second Schottky diode 332 are of the same model. The directional coupler 10 is a parallel line directional coupler 10 , and a fourth end of the parallel line directional coupler 10 is grounded through a resistor 111 .

[0059] It should be noted that the switch module 40 in each of the above embodiments may also be a PMOS field-effect transistor. The specific device can be adaptively adjusted according to the needs and characteristics of the transistor during use to achieve device interchangeability. By adopting the above-described specific structure of the switch-type non-reciprocal protection circuit 100, its circuit structure is more concise and efficient, with high reliability and lower cost, and the circuit complexity of the non-reciprocal protection circuit can be more effectively reduced.

[0060] like Figure 3Figure 1 shows the bidirectional input and output power curves of the switch-type non-reciprocal protection circuit 100, with input power on the abscissa and output power on the ordinate. The solid line represents the input and output power curves when the signal is input from the first port circuit 01 and output from the second port circuit 02; the dashed line represents the input and output power curves when the signal is input from the second port circuit 02 and output from the first port circuit 01. This demonstrates that the switch-type non-reciprocal protection circuit 100 achieves excellent bidirectional non-reciprocal limiting performance.

[0061] In one embodiment, a communication device is further provided, including a dielectric substrate and the above-mentioned switch-type non-reciprocal protection circuit 100 .

[0062] It can be understood that the description and limitations of the switch-type non-reciprocal protection circuit 100 in this embodiment can be understood in the same way as the corresponding description and limitations in the various embodiments of the switch-type non-reciprocal protection circuit 100 described above, and will not be repeated here. Those skilled in the art will understand that the communication equipment referred to here, in addition to including the dielectric substrate and the above-mentioned switch-type non-reciprocal protection circuit 100, may also include other structural components, such as but not limited to antennas (transmitting antennas or transceiver antennas), front-end feeders, rear-end feeders, transceiver switches, transmitters and / or receivers, etc., which can be understood in the same way as the structural components of common radar communication equipment in the field, and will not be described in detail one by one in this specification.

[0063] Each circuit component of the switch-type non-reciprocal protection circuit 100 can be processed and installed on a dielectric substrate to facilitate integrated packaging, improve circuit integration, reduce circuit volume, and enhance circuit reliability.

[0064] The above-mentioned communication device, by applying the above-mentioned switch-type non-reciprocal protection circuit 100, can form a switch-type limiter for the received signal to have a limiting effect on it, while not limiting the transmitted signal. With a simpler circuit structure design, efficient bidirectional non-reciprocal limiting is achieved, thereby achieving the purpose of reducing the circuit complexity of the non-reciprocal protection circuit, which is beneficial to reducing the size of the device and improving the circuit reliability.

[0065] In one embodiment, the dielectric substrate includes an FR4 substrate, an F4B substrate, a Rogers substrate, a GaAs substrate, a GaN substrate, an aluminum oxide substrate, an aluminum nitride substrate, or a sapphire substrate.

[0066] It is understood that the dielectric substrate can generally be made of any of the existing materials, including FR4, F4B, Rogers, GaAs, GaN, alumina, aluminum nitride, and sapphire. Using dielectric substrates made of these materials can effectively reduce device weight, improve device reliability, and ensure the reliable installation of various circuit components.

[0067] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0068] The above embodiments merely illustrate several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A switch-type non-reciprocal protection circuit, characterized in that: It includes a first port circuit, a directional coupler, a protection module, a detection module, a switch module and a second port circuit; The first end of the directional coupler is connected to the first port circuit, the second end of the directional coupler is connected to the first end of the protection module, the third end of the directional coupler is connected to the first end of the detection module, and the fourth end of the directional coupler is grounded; the second end of the protection module is connected to the second port circuit, the third end of the protection module is connected to the second end of the switch module, the second end of the detection module is connected to the first end of the switch module, and the third end of the switch module is grounded; the first port circuit is used to connect to the front-end feeder, and the second port circuit is used to connect to the rear-end feeder; The directional coupler is used to couple the path signal to the detection module, the detection module is used to convert the coupled signal into a detection voltage, the switch module is used to control the protection module to start working when the detection voltage is greater than the switch on-voltage, and to control the protection module not to start working when the detection voltage is less than the switch on-voltage. The protection module is used to limit the path signal that exceeds the threshold level when starting working; the coupled signal includes a received signal or a transmitted signal, and the signal power of the received signal is greater than the signal power of the transmitted signal.

2. The switch type non-reciprocal protection circuit according to claim 1, characterized in that: The directional coupler includes a parallel line directional coupler, a branch line directional coupler or a Lange directional coupler.

3. The switch type non-reciprocal protection circuit according to claim 1, characterized in that: The first port circuit includes an SMA type connector, an N type connector, a TNC type connector, a BNC type connector or an SSMA type connector.

4. The switch type non-reciprocal protection circuit according to claim 1, characterized in that: The second port circuit includes an SMA type connector, an N type connector, a TNC type connector, a BNC type connector or an SSMA type connector.

5. The switch type non-reciprocal protection circuit according to claim 1, characterized in that: The switch module includes a transistor or a field effect tube.

6. The switch type non-reciprocal protection circuit according to claim 1, characterized in that: The detection module includes a Walton voltage doubler rectifier module or a Dickson voltage doubler rectifier module.

7. The switch type non-reciprocal protection circuit according to any one of claims 1 to 6, characterized in that: The protection module includes a first capacitor, a second capacitor, a first inductor and a limiting unit, one end of the first capacitor is connected to the second end of the directional coupler, the other end of the first capacitor is respectively connected to one end of the second capacitor, one end of the first inductor and the anode of the limiting unit, the other end of the second capacitor is connected to the second port circuit, the other end of the first inductor is grounded, and the cathode of the limiting unit is connected to the second end of the switch module.

8. The switch type non-reciprocal protection circuit according to claim 7, characterized in that: The limiting unit includes a first PIN diode, a second PIN diode and a third PIN diode connected in series, the switch module is a field effect transistor, the detection module includes a third capacitor, a fourth capacitor, a second inductor, a first Schottky diode and a second Schottky diode, and the directional coupler includes a parallel line directional coupler and a resistor; The anode of the first PIN diode is connected to one end of the first inductor, the cathode of the third PIN diode is connected to the drain of the field effect transistor, the source of the field effect transistor is grounded, the gate of the field effect transistor is connected to one end of the second inductor, the other end of the second inductor is respectively connected to the cathode of the second Schottky diode and one end of the fourth capacitor, the other end of the fourth capacitor is grounded, the anode of the second Schottky diode is respectively connected to the cathode of the first Schottky diode and one end of the third capacitor, the anode of the first Schottky diode is grounded, the other end of the third capacitor is connected to the third end of the parallel line directional coupler, the fourth end of the parallel line directional coupler is grounded through the resistor, the second end of the parallel line directional coupler is connected to one end of the first capacitor, and the first end of the parallel line directional coupler is connected to the first port circuit.

9. A communication device, characterized in that: The invention comprises a dielectric substrate and the switch type non-reciprocal protection circuit according to any one of claims 1 to 8, wherein the dielectric substrate is used to carry the switch type non-reciprocal protection circuit.

10. The communication device according to claim 9, wherein: The dielectric substrate includes an FR4 substrate, an F4B substrate, a Rogers substrate, a GaAs substrate, a GaN substrate, an aluminum oxide substrate, an aluminum nitride substrate or a sapphire substrate.

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