A lightning indirect effect protection circuit of a third-generation compass communication receiver

Abstract

The application discloses a lightning indirect effect protection circuit of a Beidou third-generation communication receiver, which comprises an input matching circuit, a first protection circuit, an impedance matching circuit, a second protection circuit and an output matching circuit; the input end of the input matching circuit is connected with an input signal of a low-noise amplifier; the output end of the input matching circuit is connected with the first protection circuit; the output end of the first protection circuit is connected with the input end of the impedance matching circuit; the output end of the impedance matching circuit is connected with the input end of the second protection circuit; and the output end of the second protection circuit is connected with the input end of the output matching circuit. The lightning indirect effect protection circuit of the Beidou third-generation communication receiver can solve the problems of large parasitic capacitance, long response time and low power capacity of the traditional surge protection circuit, reduce the damage risk of sensitive devices under strong electromagnetic pulses and achieve good protection effect.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic pulse protection technology, and in particular to a lightning indirect effect protection circuit for a Beidou-3 communication receiver. Background Technology

[0002] The BeiDou-3 satellites not only support positioning and navigation services but also provide communication, SMS, and data link services, meeting a wider range of application needs. Compared to BeiDou-2, BeiDou-3 satellites not only expand their service area from regional to global coverage but also significantly improve accuracy and reliability. my country is also actively promoting the application of the BeiDou system in the civil aviation sector. The indirect effect of lightning refers to the interference caused by external lightning through various coupling mechanisms on airborne electronic equipment, leading to temporary or permanent malfunctions and seriously affecting flight safety.

[0003] Low-noise amplifiers (LNAs) are a crucial component of BeiDou-3 communication receivers. Because semiconductor transistors are particularly sensitive to electromagnetic pulses, the indirect effects of lightning can potentially damage LNAs. Common surge protection schemes combine ground-to-ground (GDT) transistors with TVS or MOV transistors. The GDT releases the large coupled current, while TVS or MOV transistors with smaller junction capacitances are preferentially turned on, accelerating the GDT's turn-on speed. However, the large parasitic capacitance of the GDT can affect the circuit's RF performance and cause freewheeling issues. The Darlington structure, with its low parasitic capacitance and excellent immunity and protection performance, presents a proposed LNA protection circuit that can suppress surges without affecting the circuit's RF performance. Summary of the Invention

[0004] The purpose of this invention is to provide a lightning indirect effect protection circuit for a Beidou-3 communication receiver, which can overcome the problems of large parasitic capacitance, long response time and low power capacity of traditional surge protection circuits, reduce the risk of damage to sensitive devices when subjected to strong electromagnetic pulses, and achieve better protection effect.

[0005] To achieve the above objectives, the present invention provides a lightning indirect effect protection circuit for a Beidou-3 communication receiver, including an input matching circuit, a primary protection circuit, an impedance matching circuit, a secondary protection circuit, and an output matching circuit;

[0006] The input terminal of the input matching circuit is connected to the input signal of the low-noise amplifier. The output terminal of the input matching circuit is electrically connected to the first-level protection circuit. The output terminal of the first-level protection circuit is electrically connected to the input terminal of the impedance matching circuit. The output terminal of the impedance matching circuit is electrically connected to the input terminal of the second-level protection circuit. The output terminal of the second-level protection circuit is electrically connected to the input terminal of the output matching circuit. The output terminal of the output matching circuit is electrically connected to the low-noise amplifier.

[0007] Preferably, the primary protection circuit includes TVS diodes D1 and D2. The input terminal of TVS diode D1 is electrically connected to the output terminal of the output matching circuit, the output terminal of TVS diode D1 is electrically connected to the input terminal of TVS diode D2, and the output terminal of TVS diode D2 is grounded. Both TVS diodes D1 and D2 are bidirectional TVS diodes, and the breakdown voltage of TVS diode D1 is greater than the breakdown voltage of TVS diode D2.

[0008] Preferably, the impedance matching circuit is a quarter-wavelength microstrip line structure.

[0009] Preferably, the secondary protection circuit adopts a Darlington structure to form a first Darlington bleed circuit and a second Darlington bleed circuit, and the first Darlington bleed circuit and the second Darlington bleed circuit have the same structure and are used in parallel.

[0010] Preferably, the main structure of the first Darlington bleeder circuit and the second Darlington bleeder circuit is a field-effect transistor and a transistor, wherein the field-effect transistor is an enhancement-mode GaN pHEMT as the driving transistor, and the transistor is a high-frequency high-power transistor as the output transistor.

[0011] Preferably, the first Darlington bleeder circuit includes a field-effect transistor M1, a transistor B1, resistors R1, R2, and R3, a diode E1, and a diode E2; the drain of the field-effect transistor M1 and the collector of the transistor B1 are electrically connected, and a lead wire from the connection end is electrically connected to the output terminal of the impedance matching circuit; the source of the field-effect transistor M1 is electrically connected to the negative terminals of resistors R1, R3, and diode E2; the other end of resistor R1 is grounded; the other end of resistor R3 is electrically connected to the base of transistor B1; the emitter of transistor B1 is electrically connected to the positive terminal of diode E2 and one end of resistor R2; the other end of resistor R2 is grounded; and diode E1 is connected in parallel between the collector and emitter of transistor B1.

[0012] Preferably, one end of the TVS diode D1 is electrically connected to one end of the TVS diode D2, and the lead wire from the connection end is electrically connected to the gate of the field-effect transistor, serving as the control terminal of the secondary protection circuit. When coupled to a lightning pulse, the TVS diodes D1 and D2 are in a clamped state, and the clamping voltage serves as the trigger signal for the field-effect transistor.

[0013] Preferably, the base of the transistor is connected to the source of the field-effect transistor, and resistors R3 and R6 are connected between the base of the transistor and the source of the field-effect transistor, while resistors R1 and R4 are connected to the source of the field-effect transistor.

[0014] Preferably, resistors R2 and R5 are connected between the emitter of the transistor and ground; a freewheeling diode is connected in parallel between the collector and emitter of the transistor; and an accelerating diode is electrically connected between the emitter of the transistor and the source of the field-effect transistor.

[0015] Preferably, both the input matching circuit and the output matching circuit are microstrip double-branch stub matching circuits.

[0016] Therefore, the beneficial effects of the lightning indirect effect protection circuit of the Beidou-3 communication receiver described above are as follows:

[0017] (1) A lightning indirect effect protection circuit is composed of a TVS trigger structure and a Darlington bleeder structure. When coupled to a lightning pulse, the TVS in the first-stage protection circuit turns on first, clamping the overvoltage to a low voltage. The clamping voltage serves as the control signal for the second-stage protection circuit, causing the field-effect transistor in the Darlington bleeder circuit to turn on. After amplifying the current, the transistor turns on to bleed the current. The parallel use of Darlington structures can enhance the bleeder capability of the circuit and achieve protection for low-noise amplifiers.

[0018] (2) The Darlington structure is used instead of the traditional transient suppression device, which makes up for the shortcomings of the traditional transient suppression device when used alone. The power capacity, response time and parasitic capacitance cannot meet the requirements at the same time. The protection circuit has the advantages of fast response speed, short response time and small parasitic capacitance. The protection circuit is integrated with the low noise amplifier, which can reduce the power loss of the circuit and make the low noise amplifier have a smaller insertion loss.

[0019] (3) Use third-generation gallium nitride pseudohigh electron mobility transistors (GaNPHEMTs) instead of traditional silicon-based materials. These transistors have lower noise figures, stronger voltage breakdown resistance, faster signal transmission rates, and better signal integrity. They are more suitable for use in high-frequency, high-voltage, high-heat, and high-power receivers such as those for BeiDou navigation systems.

[0020] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the lightning indirect effect protection circuit for a Beidou-3 communication receiver according to the present invention.

[0022] Figure 2 This is a circuit structure connection diagram of a lightning indirect effect protection circuit for a Beidou third-generation communication receiver according to the present invention;

[0023] Figure 3 The lightning waveform specified in RTCA / DO-160;

[0024] Figure 4 To protect the input and output voltage of the circuit;

[0025] Figure 5 This is the clamping voltage of the TVS diode D2;

[0026] Figure 6 To protect the input and output power of the circuit;

[0027] Figure 7 The S-parameters for the protection circuit. Detailed Implementation

[0028] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0030] Example 1

[0031] like Figure 1 As shown, the present invention provides a lightning indirect effect protection circuit for a Beidou-3 communication receiver, including an input matching circuit, a primary protection circuit, an impedance matching circuit, a secondary protection circuit, and an output matching circuit.

[0032] One port of microstrip line Tee1 is connected to the signal input of the low-noise amplifier; the second port of microstrip line Tee1 is connected to one end of microstrip line TL2; and the third port of microstrip line Tee1 is connected to one end of microstrip line TL3. One port of microstrip line Tee2 is connected to the other end of microstrip line TL2; the second port of microstrip line Tee2 is connected to the input of the first-level protection circuit; and the third port of microstrip line Tee2 is connected to one end of microstrip line TL4. The other ends of microstrip lines TL3 and TL4 are grounded.

[0033] The primary protection circuit includes TVS diodes D1 and D2. One end of TVS diode D1 is electrically connected to the output of the input matching circuit and the input of the impedance matching circuit. The other end of TVS diode D1 is electrically connected to one end of TVS diode D2. The lead wires from the connection end are electrically connected to the gates of field-effect transistors M1 and M3, serving as the control terminals of the secondary protection circuit. The other end of TVS diode D2 is grounded.

[0034] The secondary protection circuit includes MOSFET M1, transistor B1, resistors R1, R2, and R3, diodes E1 and E2; MOSFET M2, transistor B2, resistors R4, R5, and R6, diodes E3 and E4.

[0035] In the first Darlington bleed circuit, the drain of the field-effect transistor M1 is connected to the collector of the transistor B1, and the lead wire from the connection point is electrically connected to the output terminal of the quarter-microstrip line. The source of the field-effect transistor M1 is electrically connected to the negative terminals of resistors R1 and R3 and diode E2. The other end of resistor R1 is grounded, and the other end of resistor R3 is electrically connected to the base of transistor B1. The emitter of transistor B1 is electrically connected to the positive terminal of diode E2 and one end of resistor R2, and the other end of resistor R2 is grounded. Diode E1 is connected in parallel between the collector and emitter of transistor B1.

[0036] In the second Darlington bleeder circuit, the drain of field-effect transistor M2 and the collector of transistor B2 are electrically connected, and the lead wire from the connection terminal is electrically connected to the output terminal of the quarter-microstrip line; the source of field-effect transistor M1 is electrically connected to resistor R4, resistor R6, and the negative terminal of diode E4, the other end of resistor R4 is grounded, the other end of resistor R6 is electrically connected to the base of transistor B2, the emitter of transistor B2 is electrically connected to the positive terminal of diode E4 and one end of resistor R5, the other end of resistor R5 is grounded; diode E3 is connected in parallel to the collector and emitter of transistor B2.

[0037] One port of microstrip line Tee3 is connected to the output of the secondary protection circuit; two ports of microstrip line Tee3 are connected to one end of microstrip line TL5; and three ports of microstrip line Tee3 are connected to one end of microstrip line TL6. One port of microstrip line Tee4 is connected to the other end of microstrip line TL5; two ports of microstrip line Tee4 are connected to the low-noise amplifier; and three ports of microstrip line Tee4 are connected to one end of microstrip line TL7. The other ends of microstrip lines TL6 and TL7 are grounded.

[0038] The dielectric substrates of the microstrip lines in the protection circuit all use Rogers 4350C substrate, which is a hydrocarbon ceramic microwave dielectric material with a thickness of 0.635mm, a dielectric constant of 3.38, and a dielectric loss of 0.0037 at 1.5GHz.

[0039] Based on the above embodiments, the specific device selection is as follows:

[0040] Both MOSFETs M1 and M2 are enhancement-mode GAN pHEMTs, model CGH40010; both transistors B1 and B2 are NPN high-frequency high-power transistors, model MJ11012; transient suppression diodes D1 and D2 are bidirectional TVS diodes, models ESD110_B1_02EL and ESD105_B1_02EL; freewheeling diodes E1 and E3 are fast recovery diodes, models FR301-FR307; accelerating diodes E2 and E4 are Schottky diodes, model MBR20200.

[0041] The working principle of the lightning indirect effect protection circuit for a Beidou-3 communication receiver is as follows: A TVS diode triggering structure and a Darlington bleeder structure are used for the lightning indirect effect protection circuit design. When coupled to a lightning pulse, because the breakdown voltage of TVS diode D2 in the first-stage protection circuit is less than that of TVS diode D1, TVS diode D2 conducts first, clamping the overvoltage to a low voltage. The clamping voltage serves as the control signal for field-effect transistors M1 and M2 in the second-stage protection circuit, causing them to conduct. Resistors R1 and R4 are used to prevent leakage current from being amplified. The input matching circuit and output matching circuit can reduce the power loss of the input signal and improve the overall performance of the circuit.

[0042] After MOSFETs M1 and M2 conduct and amplify the current, transistors B1 and B2 are turned on. Since B1 and B2 are high-power transistors, they can discharge large currents. Resistors R2 and R5 prevent current from flowing back into the MOSFETs. The current, after passing through transistors B1 and B2, returns to the base of the transistors via Schottky diodes E2 and E4, forming positive feedback and accelerating the conduction of transistors B1 and B2. When a large instantaneous reverse current is generated in the circuit, it can be discharged through freewheeling diodes E1 and E3, protecting the collector and emitter of the transistors. Using two Darlington bleeder circuits in parallel enhances the circuit's bleedering capability, achieving protection against lightning indirect effects in the low-noise amplifier.

[0043] Therefore, the present invention adopts the above-mentioned lightning indirect effect protection circuit of a Beidou third-generation communication receiver, which makes up for the problems of large parasitic capacitance, long response time and low power capacity of traditional surge protection circuits, and can reduce the risk of damage to sensitive devices when subjected to strong electromagnetic pulses, thus achieving a better protection effect.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A lightning indirect effect protection circuit for a Beidou-3 communication receiver, characterized in that: It includes an input matching circuit, a primary protection circuit, an impedance matching circuit, a secondary protection circuit, and an output matching circuit; The input terminal of the input matching circuit is connected to the input signal of the low-noise amplifier. The output terminal of the input matching circuit is electrically connected to the first-stage protection circuit. The output terminal of the first-stage protection circuit is electrically connected to the input terminal of the impedance matching circuit. The output terminal of the impedance matching circuit is electrically connected to the input terminal of the second-stage protection circuit. The output terminal of the second-stage protection circuit is electrically connected to the input terminal of the output matching circuit. The output terminal of the output matching circuit is electrically connected to the low-noise amplifier. The primary protection circuit includes TVS diodes D1 and D2. The input terminal of TVS diode D1 is electrically connected to the output terminal of the input matching circuit, and the output terminal of TVS diode D1 is electrically connected to the input terminal of TVS diode D2. The output terminal of TVS diode D2 is grounded. Both TVS diodes D1 and D2 are bidirectional TVS diodes, and the breakdown voltage of TVS diode D1 is greater than the breakdown voltage of TVS diode D2. The secondary protection circuit adopts a Darlington structure to form a first Darlington bleed circuit and a second Darlington bleed circuit. The first Darlington bleed circuit and the second Darlington bleed circuit have the same structure and are used in parallel. The main structure of the first Darlington bleed circuit and the second Darlington bleed circuit is a field-effect transistor and a transistor. The field-effect transistor is an enhancement-mode GaN pHEMT as the driving transistor, and the transistor is a high-frequency high-power transistor as the output transistor. The first Darlington bleeder circuit includes a field-effect transistor M1, a transistor B1, resistors R1, R2, and R3, a diode E1, and a diode E2. The drain of the field-effect transistor M1 and the collector of the transistor B1 are electrically connected, and a lead wire from the connection end is electrically connected to the output terminal of the impedance matching circuit. The source of the field-effect transistor M1 is electrically connected to the cathode of resistors R1 and R3 and the diode E2. The other end of resistor R1 is grounded, the other end of resistor R3 is electrically connected to the base of transistor B1, and the emitter of transistor B1 is electrically connected to the anode of diode E2 and one end of resistor R2. The other end of resistor R2 is grounded. The diode E1 is connected in parallel between the collector and emitter of transistor B1.

2. The lightning indirect effect protection circuit for a Beidou-3 communication receiver according to claim 1, characterized in that: The impedance matching circuit is a quarter-wavelength microstrip line structure.

3. The lightning indirect effect protection circuit for a Beidou-3 communication receiver according to claim 1, characterized in that: One end of the TVS diode D1 is electrically connected to one end of the TVS diode D2. The lead wires from the connection end are electrically connected to the gates of the field-effect transistors in the first Darlington bleed circuit and the second Darlington bleed circuit, respectively, serving as the control terminals of the secondary protection circuit. When coupled to a lightning pulse, the TVS diodes D1 and D2 are in a clamped state, and the clamping voltage serves as the trigger signal for the field-effect transistors.

4. The lightning indirect effect protection circuit for a Beidou-3 communication receiver according to claim 1, characterized in that: In both the first and second Darlington bleeder circuits, the bases of the transistors are connected to the source of the field-effect transistor in the same circuit. A resistor R3 is connected between the base of the transistor and the source of the field-effect transistor in the first Darlington bleeder circuit, and a resistor R6 is connected between the base of the transistor and the source of the field-effect transistor in the second Darlington bleeder circuit. The source of the field-effect transistor in the first Darlington bleeder circuit is connected to a resistor R1, and the source of the field-effect transistor in the second Darlington bleeder circuit is connected to a resistor R4.

5. The lightning indirect effect protection circuit for a Beidou-3 communication receiver according to claim 1, characterized in that: In the first Darlington bleeder circuit, a resistor R2 is connected between the emitter of the transistor and ground, and in the second Darlington bleeder circuit, a resistor R5 is connected between the emitter of the transistor and ground. A freewheeling diode is connected in parallel between the collector and emitter of the transistor in both the first and second Darlington bleeder circuits. An accelerating diode is electrically connected between the emitter of the transistor in both the first and second Darlington bleeder circuits and the source of the field-effect transistor.

6. The lightning indirect effect protection circuit for a Beidou-3 communication receiver according to claim 1, characterized in that: Both the input matching circuit and the output matching circuit are microstrip double-branch stub matching circuits.

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