A simulation method for electrothermal failure of cascaded PIN diode limiters based on field-circuit collaboration

Abstract

The present invention discloses a method for simulating electrothermal failure of a cascaded PIN diode limiter based on field-circuit collaboration, comprising: converting a transmission line in the cascaded PIN limiter into an equivalent lumped circuit element, and establishing a field-circuit collaboration simulation model of the limiter based on the lumped circuit element; obtaining temperature dependence equations of specific heat capacity and thermal conductivity, and correcting a physical model of thermal conductivity and specific heat capacity of the limiter circuit based on the temperature dependence equations of specific heat capacity and thermal conductivity; obtaining the temperature field and electric field distribution inside the limiter based on the field-circuit collaboration simulation model and the physical model, in combination with a thermal damage criterion for the limiter under the action of a high-power microwave pulse; and obtaining a thermal breakdown damage position inside the limiter based on the temperature field and electric field distribution.

Description

Technical Field

[0001] The present invention belongs to the field of microwave circuits, and in particular relates to an electrothermal failure simulation method of a cascaded PIN diode limiter based on field-circuit collaboration. Background Art

[0002] The circuit models of limiters mainly include equivalent lumped R, L, and C simulation circuit models based on semiconductor PIN diode devices and field-circuit collaborative simulation models based on semiconductor devices. Using the equivalent lumped circuit model based on semiconductor devices, the simulation solution can only obtain the electrical response characteristics of the limiter during the pulse action, but cannot obtain the multi-physical field distribution during the pulse action in real time. The solution is inaccurate and cannot reflect the actual response of the limiter under the pulse action. The current field-circuit simulation model of the limiter based on semiconductor PIN diode devices ignores the role of the transmission line in the limiter and cannot truly reflect the distribution of the electric field inside the device under the action of the signal. In addition, when conducting research and analysis on the failure mechanism of the limiter at high temperature, the current limiter model does not consider the temperature dependence of thermal parameters. Since thermal conductivity is closely related to the heat diffusion process inside the device, the solution of the temperature equation is inaccurate.

[0003] In summary, the current limiter simulation circuit model cannot accurately solve the true response process inside the limiter during the action of the pulse signal, that is, the true distribution of the electric field and temperature field, and cannot effectively carry out research on the thermal damage and failure characteristics of the limiter. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention proposes a field-circuit synergy-based cascaded PIN diode limiter electrothermal failure simulation method, which can realize the study of the thermal failure damage mechanism of the limiter during the pulse action of the limiter.

[0005] To achieve the above objectives, the present invention provides a method for simulating electrothermal failure of a cascaded PIN diode limiter based on field-circuit synergy, comprising:

[0006] The transmission line in the cascaded PIN limiter is converted into an equivalent lumped circuit element, and a field-circuit co-simulation model of the limiter is established based on the lumped circuit element;

[0007] Obtaining the temperature dependence equation of the specific heat capacity of silicon and the temperature dependence equation of the thermal conductivity of silicon respectively, and modifying the physical model of the thermal conductivity and specific heat capacity of the limiter circuit based on the temperature dependence equation of the specific heat capacity and the temperature dependence equation of the thermal conductivity;

[0008] Based on the field-circuit collaborative simulation model and the physical model, combined with the thermal damage criterion of the limiter under the action of high-power microwave pulses, the temperature field and electric field distribution inside the limiter are obtained;

[0009] Based on the temperature field and electric field distribution, the internal thermal breakdown damage position of the limiter is obtained.

[0010] Optionally, converting the quarter-wavelength transmission line in the cascaded PIN limiter into an equivalent lumped circuit element includes:

[0011] Divide the first wavelength transmission line into two second wavelength transmission lines of equal length, wherein the wavelength of the first wavelength transmission line is twice the wavelength of the second wavelength transmission line;

[0012] The two-port microwave networks of the two equal-length second wavelength transmission lines are converted into corresponding circuit elements.

[0013] Optionally, a method for converting the two equal-length one-eighth wavelength transmission lines into a two-port microwave network is as follows:

[0014] V1=I1Z 11 -I2Z 12

[0015] V2=I1Z 21 -I2Z 22

[0016] Where V1 and I1 are the voltage and current at the input port, respectively; V2 and I2 are the voltage and current at the output port, respectively. The negative sign indicates that the current at port 2 points outward. Z 11 and Z 22 are the voltage and current transfer coefficients respectively; Z 12 is the transfer impedance, Z 21 is the transfer admittance.

[0017] Optionally, the field-circuit collaborative simulation model of the limiter includes: a first-stage diode, two sections of second-wavelength transmission lines, a radio frequency choke inductor, and a second-stage diode;

[0018] The first-stage diode, the second wavelength transmission line, the radio frequency choke inductor, the second wavelength transmission line and the second-stage diode are connected in sequence.

[0019] Optionally, a method for obtaining the temperature dependence equation of the specific heat capacity is:

[0020] χ = -3.22 × 10 -7 ×T 2 +0.004257×T-0.5020

[0021] Where χ is the thermal resistivity coefficient and T is the temperature.

[0022] Optionally, a method for obtaining the thermal conductivity temperature dependence equation is:

[0023] c L =1.063+0.002513×T-1.339×10 -6 ×T 2 +3.124×10 -10 ×T 3

[0024] Among them, c L is the thermal capacitance coefficient, and T is the device temperature.

[0025] Optionally, the thermal damage criterion of the limiter under the action of the high-power microwave pulse is:

[0026] The failure criterion of thermal damage to the limiter is when the maximum temperature of the internal components of the limiter reaches the melting point of the material under the action of high-power microwave pulse signal.

[0027] Optionally, obtaining the internal thermal breakdown damage position of the limiter includes:

[0028] Based on the temperature field, determining a maximum temperature region inside the limiter;

[0029] When the maximum temperature of the maximum temperature area reaches the melting point, thermal breakdown occurs, and the thermal breakdown damage position is obtained.

[0030] Compared with the prior art, the present invention has the following advantages and technical effects:

[0031] The cascaded PIN limiter circuit of the present invention takes into account the impedance transformation function of the quarter-wavelength transmission line, and the circuit model can more accurately describe the voltage amplitude distribution at the input and output ports of the limiter under the action of an external signal;

[0032] The limiter circuit model in the present invention modifies the thermal conductivity and specific heat capacity temperature model of silicon in the PIN diode. When conducting thermal failure research on the limiter, the influence of the temperature field distribution at different positions of the device on the thermal parameters is considered, especially in the high temperature area of the device.

[0033] When the present invention studies the thermal damage of a limiter under the action of a high-power pulse, the temperature response at different internal positions can be accurately solved and the thermal failure area of the limiter can be determined.

[0034] The present invention uses this model to perform device-circuit hybrid simulation and accurately obtain the limiting characteristic curve of the limiter;

[0035] The present invention uses this model to carry out research on thermal failure damage of the limiter under the action of high-power microwave pulses and determine the damage failure position of the limiter. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings:

[0037] Figure 1 This is a flow chart of a method for simulating electrothermal failure of a cascaded PIN diode limiter based on field-circuit collaboration according to an embodiment of the present invention;

[0038] Figure 2 1 is a schematic diagram of the structure of a cascaded PIN diode limiter according to an embodiment of the present invention; wherein: 1. a quarter-wavelength transmission line; 2. a PIN diode at the limiter input end; 3. a PIN diode at the limiter output end; 4. an RF choke inductor; 5. a DC blocking capacitor at the input port; and 6. a DC blocking capacitor at the output port.

[0039] Figure 3 7 is a schematic diagram of an equivalent structure of a cascaded PIN diode limiter according to an embodiment of the present invention; wherein 7 is the first half of a one-eighth wavelength transmission line, and 8 is the second half of a one-eighth wavelength transmission line;

[0040] Figure 4 Schematic diagram of a two-port microwave network of a one-eighth wavelength transmission line according to an embodiment of the present invention;

[0041] Figure 5 is a schematic diagram of an equivalent circuit model of a one-eighth wavelength transmission line according to an embodiment of the present invention;

[0042] Figure 6 1. It is a schematic diagram of a device-circuit hybrid simulation circuit of a cascaded PIN diode limiter according to an embodiment of the present invention;

[0043] Figure 7 2. It is a schematic diagram of simulation results of the limiting characteristic curve of the limiter according to an embodiment of the present invention;

[0044] Figure 8 Schematic diagram of the spatial distribution of the temperature field inside the input-end PIN diode when it fails due to thermal damage according to an embodiment of the present invention. DETAILED DESCRIPTION

[0045] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0046] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0047] This invention primarily addresses the shortcoming of limiter simulation circuit models that fail to consider the effects of transmission lines. By leveraging transmission line equivalence theory, the microstrip transmission lines in the limiter are converted into equivalent circuit elements, establishing a field-circuit co-simulation model of the limiter during pulse action. Furthermore, to ensure the accuracy of the temperature equations for the limiter device during pulse damage and failure studies, a method for correcting the thermal parameter model of semiconductor materials is proposed. Ultimately, using this field-circuit co-simulation model of the limiter, the limiting characteristic curve and thermal damage failure mechanism of the limiter are simulated.

[0048] The present invention proposes a method for simulating the electrothermal failure of a cascaded PIN diode limiter based on field-circuit synergy. Figure 1 As shown, the specific steps include:

[0049] The transmission lines in the cascaded PIN limiter are converted into equivalent lumped circuit elements. Based on the lumped circuit elements, a field-circuit co-simulation model of the limiter is established.

[0050] The temperature dependence equation of the specific heat capacity of silicon and the temperature dependence equation of the thermal conductivity of silicon are obtained respectively, and the physical models of the thermal conductivity and specific heat capacity of the limiter circuit are modified based on the temperature dependence equation of the specific heat capacity and the temperature dependence equation of the thermal conductivity;

[0051] Based on the field-circuit collaborative simulation model and physical model, combined with the thermal damage criterion of the limiter under the action of high-power microwave pulses, the temperature field and electric field distribution inside the limiter are obtained;

[0052] Based on the temperature field and electric field distribution, the internal thermal breakdown damage position of the limiter is obtained.

[0053] Furthermore, converting the transmission line in the cascaded PIN limiter into an equivalent lumped circuit element includes:

[0054] The first wavelength transmission line is divided into two second wavelength transmission lines of equal length, wherein the wavelength of the first wavelength transmission line is twice the wavelength of the second wavelength transmission line;

[0055] A two-port microwave network of two equal-length second wavelength transmission lines is converted into corresponding circuit elements.

[0056] Specifically, the present invention divides a quarter-wavelength transmission line into one-eighth-wavelength transmission lines of equal length at both ends according to the positions of the RF choke inductor and the two PIN diodes in the limiter circuit, and the signal flow direction inside the structure when the signal acts on the limiter, according to the position of the transmission line.

[0057] Specifically, the cascaded PIN limiter utilizes the "impedance transformation" function of the quarter-wavelength transmission line 1 to ensure that the PIN diodes at the input and output ports of the limiter have different voltage amplitudes.

[0058] According to the positions of two sections of one-eighth wavelength transmission lines, two PIN diodes and a radio frequency choke inductor, the present invention regards the cascaded PIN diode limiter circuit as a series circuit of five dual-port microwave networks.

[0059] To obtain the equivalent circuit of the limiter, the present invention converts the two-port microwave network of two eighth-wavelength transmission lines into corresponding circuit elements. The present invention calculates them based on the distributed parameter model equivalence principle to obtain the equivalent circuit of the two transmission lines.

[0060] Furthermore, the field-circuit collaborative simulation model of the limiter includes: a first-stage diode, two sections of one-eighth wavelength transmission lines, a radio frequency choke inductor, and a second-stage diode;

[0061] The first-stage diode, the one-eighth wavelength transmission line, the radio frequency choke inductor, the one-eighth wavelength transmission line and the second-stage diode are connected in sequence.

[0062] Specifically, the invention connects a PIN diode, an RF choke inductor, and a transmission line equivalent circuit to create a field-circuit co-simulation circuit for a cascaded PIN diode limiter. This circuit model can be used to perform multi-physics hybrid simulations of the cascaded PIN diode limiter.

[0063] Specifically, the thermal damage failure of the limiter in the present invention is related to the temperature field distribution within the limiter device under the action of high-power microwave pulse signals. In the process of solving the device's temperature field, the thermal conductivity and specific heat capacity of the material often play a significant role. However, the thermal conductivity and specific heat capacity of semiconductor materials are functions of temperature and vary with temperature. To ensure the accuracy of the internal temperature field solution of the cascaded PIN limiter device under the action of high-power microwave pulses, the present invention proposes to modify the specific heat capacity and thermal conductivity model of the limiter material.

[0064] The material of the limiter in the present invention is silicon. The specific heat capacity and thermal conductivity values of silicon under different temperature conditions are obtained through experimental testing. The test data are fitted to obtain the temperature dependence equations of the specific heat capacity and thermal conductivity of silicon, thereby correcting the thermal conductivity and specific heat capacity model of the limiter circuit;

[0065] Specifically, based on the temperature dependence equation of specific heat capacity and thermal conductivity, the coefficients of different powers of temperature in the temperature equation are substituted into the solution parameter file of the material silicon, thereby correcting the physical model of thermal conductivity and specific heat capacity of the limiter circuit.

[0066] Furthermore, the thermal damage criterion of the limiter under the action of high-power microwave pulses is:

[0067] The failure criterion of thermal damage to the limiter is when the maximum temperature of the internal components of the limiter reaches the melting point of the material under the action of high-power microwave pulse signal.

[0068] Specifically, under the influence of high-power microwave pulse signals, the maximum temperature of a localized region within the limiter structure often rises to the melting point of the material, causing it to melt and fail due to thermal breakdown, resulting in permanent and irreversible damage. Therefore, the invention uses the maximum temperature of the internal components of the limiter reaching the melting point of the silicon material under the influence of high-power microwave pulse signals as the failure criterion for thermal damage to the limiter.

[0069] Furthermore, obtaining the location of thermal breakdown damage inside the limiter includes:

[0070] Based on the temperature field, determine the maximum temperature area inside the limiter;

[0071] When the maximum temperature of the maximum temperature area reaches the melting point, thermal breakdown occurs, and the thermal breakdown damage position is obtained.

[0072] Specifically, the limiter circuit model of the present invention accurately simulates the real-time distribution of the electric and temperature fields within the limiter device under the action of high-power microwave pulses. The temperature field can be used to determine the region within the limiter device where the maximum temperature lies. When the maximum temperature reaches the melting point, thermal breakdown damage and failure occur.

[0073] The region where the maximum temperature of the limiter in the present invention rises to the melting point is the location where thermal damage to the limiter occurs.

[0074] The basic process of the electrical failure simulation method of the cascaded PIN limiter in the present invention is as follows: Figure 1 As shown in the figure, by converting the transmission lines in a cascaded PIN limiter into equivalent lumped circuit elements, a field-circuit collaborative multi-physics simulation circuit model of the limiter is established. This model allows the electric field and temperature field responses of the limiter's internal components to the application of high-power microwave pulses when solving the limiter's electrical characteristics. To account for the influence of the device material's temperature distribution on its electrical conductivity and specific heat capacity, equations for the temperature dependence of silicon's specific heat capacity and thermal conductivity are derived, and the physical models of the thermal conductivity and specific heat capacity of the limiter circuit are modified. Finally, this field-circuit model is used to study the thermal damage failure of the limiter under high-power microwave pulse signals and to determine the location of the breakdown damage in the limiter under high-power microwave pulse signals.

[0075] The actual structure diagram of the limiter in the present invention is as follows Figure 2As shown. The limiter mainly consists of a PIN diode 2 (denoted as PIN1) at the input port, a PIN diode 3 (denoted as PIN2) at the output port, a microstrip line connecting the two PIN diodes, and an RF choke inductor that passes DC. When using the limiter field-circuit collaborative simulation circuit model to analyze and calculate the electrical and thermal characteristics of the limiter, a transmission line model cannot be established. However, the transmission line plays a very important role in the limiter, so the invention uses the transmission line equivalent theory to convert it into the corresponding circuit R, L, and C components, where C includes the input port DC blocking capacitor 5 and the output port DC blocking capacitor 6.

[0076] In the present invention, according to the transmission path of the limiter signal and the connection relationship between each circuit element, the Figure 2 The limiter circuit shown is equivalent to Figure 3 The circuit structure of five two-port microwave networks is shown in Figure 1. The two-port microwave networks consist of PIN1, an eighth-wavelength transmission line, an RF choke inductor 4, an eighth-wavelength transmission line, and PIN2. While numerical simulations can directly model the circuits of the limiter diodes PIN1 and PIN2 and the inductor L, a distributed parameter model of the transmission line cannot be directly constructed; it must be equivalently modeled as corresponding circuit elements.

[0077] The two-port microwave network structure of a single eighth-wavelength transmission line in the present invention is as follows: Figure 4 The structural dimension parameters of the transmission line can be used to obtain the electrical characteristic parameters of the transmission line, which can be expressed using the transmission matrix. Figure 4 The relationship between the voltage and current at port 1 and port 2 of the transmission line is:

[0078]

[0079] Specifically, it is expressed in matrix form:

[0080]

[0081] In the present invention, when the transmission matrix is used to represent the voltage and current relationship between the two ends of the transmission line, the Z matrix of the two-port microwave network can be calculated according to the ABCD matrix formula of the two-port microwave network.

[0082] In the present invention, the direction of the current I2 in the Z matrix is expressed as Figure 4 The direction shown, then:

[0083]

[0084] The present invention obtains an equivalent R, L, C circuit of a λ / 8 transmission line, and its specific structure is as follows: Figure 5 shown.

[0085] The present invention combines the equivalent circuit of two sections of one-eighth wavelength transmission line with PIN1, radio frequency choke inductor, and PIN2 according to Figure 3 The field-path cooperative circuit model of the cascaded PIN diode limiter is finally obtained, as shown in Figure 6 shown.

[0086] The present invention uses the field-path coordination circuit of the limiter, and the limiter characteristic curve obtained by simulation is as follows: Figure 7 As shown in the figure, when the input power is below 17dBm, the insertion loss is very small and the limiter has almost no limiting effect. When the input power exceeds 17dBm, the limiter begins to limit the amplitude. When the limiter equivalent circuit in the invention is used for simulation, the limiting characteristic curve of the limiter can be well obtained.

[0087] In order to use the limiter circuit model to perform damage failure analysis of the limiter, the present invention modifies the thermal parameter model of the semiconductor material silicon in the limiter under high temperature conditions.

[0088] Specifically, the invention obtains the temperature dependence equation of silicon thermal conductivity through experimental testing:

[0089] χ = -3.22 × 10 -7 ×T 2 +0.004257×T-0.5020 (4)

[0090] Specifically, the invention obtains the temperature dependence equation of the specific heat capacity of silicon through testing:

[0091] c L =1.063+0.002513×T-1.339×10 -6 ×T 2 +3.124×10 -10 ×T 3 (5)

[0092] The present invention utilizes a limiter circuit to conduct damage and failure research under the action of a high-power microwave pulse signal and determines the damage and failure position of the limiter.

[0093] Specifically, the present invention obtains the temperature field spatial distribution of the input end PIN diode when the limiter thermal damage failure occurs as follows: Figure 8 As shown, the limiting thermal damage failure position is determined to be the middle of the input PIN diode I region.

[0094] The above are merely preferred embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for simulating electrothermal failure of cascaded PIN diode limiters based on field-circuit synergy, characterized in that: include: The transmission line in the cascaded PIN limiter is converted into an equivalent lumped circuit element, and a field-circuit co-simulation model of the limiter is established based on the lumped circuit element; Obtaining a temperature dependence equation of the specific heat capacity of silicon and a temperature dependence equation of the thermal conductivity of silicon, respectively, and modifying the physical models of the thermal conductivity and specific heat capacity of the limiter circuit based on the temperature dependence equation of the specific heat capacity and the temperature dependence equation of the thermal conductivity; The method for obtaining the temperature dependence equation of the specific heat capacity is: x=-3.22×10 -7 ×T 2 +0.004257×T-0.5020 Where χ is the thermal resistivity coefficient and T is the device temperature; The method to obtain the temperature dependence equation of the thermal conductivity is: c L =1.063+0.002513×T-1.339×10 -6 ×T 2 +3.124×10 -10 ×T 3 Among them, c L is the thermal capacitance coefficient, T is the device temperature; Based on the field-circuit collaborative simulation model and the physical model, combined with the thermal damage criterion of the limiter under the action of high-power microwave pulses, the temperature field and electric field distribution inside the limiter are obtained; Based on the temperature field and electric field distribution, the internal thermal breakdown damage position of the limiter is obtained.

2. The method for simulating electrothermal failure of a cascaded PIN diode limiter based on field-circuit synergy according to claim 1, characterized in that: Converting the transmission line in the cascaded PIN limiter into an equivalent lumped circuit element involves: Divide the first wavelength transmission line into two second wavelength transmission lines of equal length, wherein the wavelength of the first wavelength transmission line is twice the wavelength of the second wavelength transmission line; The two-port microwave networks of the two equal-length second wavelength transmission lines are converted into corresponding circuit elements.

3. The method for simulating electrothermal failure of a cascaded PIN diode limiter based on field-circuit synergy according to claim 2, characterized in that: The method of converting the two-port microwave network of the two equal-length one-eighth wavelength transmission lines into corresponding circuit elements is as follows: V1=I1Z 11 -I2Z 12 <h2 style=";text-align:left;direction:ltr">V2=I1Z<h2 style=";text-align:left;direction:ltr"> 21 <h2 style=";text-align:left;direction:ltr"> -I2Z<h2 style=";text-align:left;direction:ltr"> 22 Among them, V1 and I1 are the voltage and current at the input port, V2 and I2 are the voltage and current at the output port, Z 11 and Z 22 are the voltage and current transfer coefficients, Z 12 is the transfer impedance, Z 21 is the transfer admittance.

4. The method for simulating electrothermal failure of a cascaded PIN diode limiter based on field-circuit synergy according to claim 2, characterized in that: The field-circuit collaborative simulation model of the limiter includes: a first-stage diode, two sections of second-wavelength transmission lines, a radio frequency choke inductor and a second-stage diode; The first-stage diode, the second wavelength transmission line, the radio frequency choke inductor, the second wavelength transmission line and the second-stage diode are connected in sequence.

5. The method for simulating electrothermal failure of a cascaded PIN diode limiter based on field-circuit synergy according to claim 1, characterized in that: The thermal damage criterion of the limiter under the action of the high-power microwave pulse is: The failure criterion of thermal damage to the limiter is when the maximum temperature of the internal components of the limiter reaches the melting point of the material under the action of high-power microwave pulse signal.

6. The method for simulating electrothermal failure of a cascaded PIN diode limiter based on field-circuit synergy according to claim 1, characterized in that: Obtaining the internal thermal breakdown damage position of the limiter includes: Based on the temperature field, determining a maximum temperature region inside the limiter; When the maximum temperature of the maximum temperature area reaches the melting point, thermal breakdown occurs, and the thermal breakdown damage position is obtained.

Images