Method and system for soa extraction of radio frequency devices based on dynamic load lines

Abstract

The application discloses a kind of based on dynamic load line's radio frequency device SOA extraction method and system, comprising: S101, output preset bias voltage and certain bias current to radio frequency device;S102, at the output end of radio frequency device, first impedance is set to make the dynamic load line of the output end of radio frequency device close to vertical state;S103, increase the input power of radio frequency device to make the swing of dynamic load line in vertical direction increase, obtain the swing upper limit that makes radio frequency device burn out, as SOA boundary point;S104, repeat S101-S103, obtain the SOA boundary point under all preset bias voltage;S105, all SOA boundary points are connected, and the SOA curve of radio frequency device is obtained.The application uses radio frequency test method, dynamic load line shape is controlled by impedance, and under different bias voltage, by increasing input power, device appears burnout, and the SOA curve of radio frequency device under real working state is obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of semiconductor technology, in particular to a radio frequency device SOA extraction method and system based on dynamic load line. BACKGROUND

[0002] The safe operating area (SOA) of a radio frequency device is one of the important indicators for evaluating the durability and reliability of the device, which refers to the range of voltage / current conditions under which a radio frequency or power semiconductor device (such as a bipolar transistor, field effect transistor, thyristor, and insulated gate bipolar transistor) can operate normally without causing damage, and is used to confirm whether the transistor is working under safe conditions.

[0003] Currently, the extraction method for SOA of a radio frequency device mainly uses direct current (DC) test. First, the transistor is biased to a certain current density, and the drain / cathode voltage is scanned until the device is burned out, at which time the voltage and current are SOA points. By recording the voltage and current when the device is burned out under a series of different bias voltage settings, the SOA of the device is formed. The biggest problem with this method is that DC scanning causes serious heat loss to the device. However, the real working state of a radio frequency device is close to pulsed current and voltage bias, and there is no such serious heat loss situation (both radio frequency signals and pulse signals are input signals with small duty cycles, while direct current signals are signals with a duty cycle of 1. For a radio frequency device, the greater the duty cycle of the input signal, the more significant the thermal effect. Therefore, the SOA curve extracted by DC scanning has a large deviation from the SOA curve under the real working state of the device. SUMMARY

[0004] The present application aims to overcome the shortcomings of the prior art and proposes a radio frequency device SOA extraction method and model parameter extraction method based on dynamic load line. The method uses a radio frequency test method to control the shape of the dynamic load line through impedance, and under different bias voltages, the device is burned out by increasing the input power to obtain the SOA curve under the real working state of the radio frequency device.

[0005] The technical solution adopted by the present application to solve its technical problems is as follows:

[0006] On the one hand, a radio frequency device SOA extraction method based on dynamic load line includes:

[0007] S101, outputting a preset bias voltage and a certain bias current to a radio frequency device;

[0008] S102, setting a first impedance at the output end of the radio frequency device to make the dynamic load line of the output end of the radio frequency device close to a vertical state;

[0009] S103, continuously increasing the input power of the radio frequency device to increase the swing of the dynamic load line in the vertical direction, obtaining an upper limit of the swing that causes the radio frequency device to burn out, and taking the upper limit of the swing as the SOA boundary point;

[0010] S104, repeating S101-S103 to obtain the SOA boundary points under all preset bias voltages;

[0011] S105, connecting all SOA boundary points to obtain the SOA curve of the radio frequency device.

[0012] Preferably, before S105, further comprising:

[0013] outputting a maximum bias voltage and a certain bias current to the radio frequency device;

[0014] setting a second impedance at the output end of the radio frequency device to make the dynamic load line of the output end of the radio frequency device close to a horizontal state;

[0015] continuously increasing the input power of the radio frequency device to increase the swing of the dynamic load line in the horizontal direction, obtaining an upper limit of the swing that causes the radio frequency device to burn out, and taking the upper limit of the swing as the SOA boundary point.

[0016] Preferably, the first impedance includes fundamental wave impedance, second harmonic wave impedance and third harmonic wave impedance.

[0017] Preferably, the second impedance includes fundamental wave impedance, second harmonic wave impedance and third harmonic wave impedance.

[0018] Preferably, the number and size of the preset bias voltages are defined according to the specifications of the radio frequency device.

[0019] Preferably, the preset bias voltage is less than a maximum bias voltage, and the maximum bias voltage is close to the breakdown voltage of the output end of the radio frequency device to ground.

[0020] Preferably, the preset bias voltage is output to the radio frequency device in order from small to large.

[0021] Preferably, S101 specifically comprises:

[0022] outputting a preset bias voltage to the output end of the radio frequency device and outputting a certain bias current to the input end of the radio frequency device.

[0023] Preferably, the radio frequency device includes a GaAs radio frequency device or a GaN radio frequency device; when the radio frequency device is a GaAsPHEMT radio frequency device or a GaN HEMT radio frequency device, the input end is a gate and the output end is a drain; when the radio frequency device is a GaAs HBT radio frequency device, the input end is a base and the output end is a collector.

[0024] In another aspect, a radio frequency device SOA extraction system based on a dynamic load line, based on the radio frequency device SOA extraction method, comprising: a signal source, a power amplifier, a radio frequency device, a direct current bias module, a dynamic load line tester and a load pulling module;

[0025] The signal source is configured to output radio frequency power to the power amplifier.

[0026] The power amplifier is configured to amplify the power input by the signal source and connect the amplified power to the input end of the radio frequency device.

[0027] The direct current bias module is configured to output a preset bias voltage and a bias current to the radio frequency device.

[0028] The dynamic load line tester is configured to collect voltage and current waveforms on the output end of the radio frequency device, and combine the voltage and current waveforms to output a dynamic load line.

[0029] The load pulling module is configured to set the impedance of the output end of the radio frequency device.

[0030] The present application has the following beneficial effects:

[0031] (1) The present application uses a radio frequency test method to control the shape of the dynamic load line to be close to a vertical state by impedance, and to increase the swing in the vertical direction by increasing the input power under different bias voltages, ultimately causing the device to burn out, thereby obtaining a series of SOA boundary points of the radio frequency device under the real working state.

[0032] (2) When the output end bias voltage of the radio frequency device approaches the breakdown voltage of the device (the maximum bias voltage), the present application controls the shape of the dynamic load line to be close to a horizontal state by impedance, and increases the swing in the horizontal direction by increasing the input power, ultimately causing the device to burn out, thereby detecting larger SOA boundary points, and combining the SOA boundary points obtained in the vertical direction to obtain the SOA curve of the radio frequency device under the real working state.

[0033] (3) The first impedance of the present application includes fundamental impedance, second harmonic impedance and third harmonic impedance, so that the dynamic load line of the output end of the radio frequency device can be close to a vertical state (so that the phase is 180°, close to a short circuit state); the second impedance of the present application includes fundamental impedance, second harmonic impedance and third harmonic impedance, so that the dynamic load line of the output end of the radio frequency device can be close to a horizontal state (so that the phase is 0°, close to an open circuit state).

[0034] The application will be described in further detail below in conjunction with the accompanying drawings and embodiments, but the dynamic load line based SOA extraction method and model parameter extraction method of the radio frequency device of the application is not limited to the embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 The basic flow chart of the dynamic load line based SOA extraction method of the embodiment of the application;

[0036] Figure 2 The dynamic load line in the vertical direction of the embodiment of the application;

[0037] Figure 3 The dynamic load line in the horizontal direction of the embodiment of the application;

[0038] Figure 4 The complete dynamic load line of the embodiment of the application;

[0039] Figure 5 The overall flow chart of the dynamic load line based SOA extraction method of the embodiment of the application;

[0040] Figure 6 The comparison chart of the SOA curve extracted by the method of the application and the SOA curve extracted by the prior art direct current test;

[0041] Figure 7 The relationship chart of the measured failure point one dynamic load line and the SOA curve extracted by the method of the application;

[0042] Figure 8 The relationship chart of the measured failure point two dynamic load line and the SOA curve extracted by the method of the application;

[0043] Figure 9 The structural block diagram of the dynamic load line based SOA extraction system of the embodiment of the application. DETAILED DESCRIPTION

[0044] In the description of the application, it should be noted that the terms “comprise”, “contain” or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitation, the element defined by the statement “comprises a…” does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0045] In the description of the present application, it should be noted that the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0046] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "provided with", "sleeved / connected", "connected" and the like should be broadly understood, for example, "connected" can be fixedly connected, or can be detachably connected, or integrally connected, can be mechanically connected, or can be electrically connected, can be directly connected, or indirectly connected through an intermediate medium, can be internal communication of two elements, and those skilled in the art can understand the specific meaning of the above terms in the present application according to the specific circumstances.

[0047] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the step identifiers S101, S102, S103 and the like are only for the convenience of description, and do not indicate the execution order, and the corresponding execution order can be adjusted.

[0048] Referring to Figure 1 A radio frequency device SOA extraction method based on dynamic load line, comprising:

[0049] S101, outputting a preset bias voltage and a certain bias current to the radio frequency device;

[0050] S102, setting a first impedance at the output end of the radio frequency device to make the dynamic load line of the output end of the radio frequency device close to the vertical state;

[0051] S103, continuously increasing the input power of the radio frequency device to increase the swing of the dynamic load line in the vertical direction, obtaining the swing upper limit of the radio frequency device burning out, and taking the swing upper limit as the SOA boundary point;

[0052] S104, repeating S101-S103 to obtain the SOA boundary point under all preset bias voltages;

[0053] S105, connecting all SOA boundary points to obtain the SOA curve of the radio frequency device.

[0054] Specifically, the radio frequency device to be tested of the embodiment is connected with a direct current bias module, and the direct current bias module can output a preset bias voltage and an output bias current to the radio frequency device. Further, in S101, the preset bias voltage is output to the output end of the radio frequency device, and a certain bias current is output to the input end of the radio frequency device.

[0055] In this embodiment, the radio frequency device may include a GaAs radio frequency device or a GaN radio frequency device; when the radio frequency device is a GaAs PHEMT radio frequency device or a GaN HEMT radio frequency device, the input terminal is the gate and the output terminal is the drain; when the radio frequency device is a GaAs HBT radio frequency device, the input terminal is the base and the output terminal is the collector.

[0056] It should be noted that, depending on the type of actual radio frequency device, the output terminal can also be an emitter or a source, and this embodiment does not impose any restrictions on this.

[0057] In S102, a first impedance is set at the output of the RF device to make the dynamic load line at the output of the RF device nearly vertical. This is specifically set and adjusted through the load pulling module. During actual testing, it can be controlled through the UI interface of the load pulling module, such as by directly inputting the required impedance value or selecting a pre-set impedance value. The load pulling module is an existing RF module that can achieve impedance transformation at a specific frequency and connect to the collector or drain of the RF device under test.

[0058] In this embodiment, the first impedance includes the fundamental impedance, the second harmonic impedance, and the third harmonic impedance. A first impedance is set at the output terminal of the RF device to make the dynamic load line at the output terminal nearly vertical. Specifically, this is achieved by controlling the fundamental impedance, the second harmonic impedance, and the third harmonic impedance to make the dynamic load line nearly vertical.

[0059] In one embodiment, by controlling the fundamental impedance, second harmonic impedance, and third harmonic impedance to make the impedance value less than 5 ohms and the phase equal to 180°, i.e., close to a short circuit state (the smaller the resistance, the closer the impedance is to a complete short circuit), the dynamic load line can be made to approach a vertical state. When the dynamic load line is close to a vertical state, the absolute value of the slope of the dynamic load line is greater than 80mA / V.

[0060] In S103, the input power of the RF device is continuously increased, which increases the swing of the dynamic load line in the vertical direction. Specifically, the power input from the signal source is amplified by a power amplifier and output to the input terminal (base / gate) of the RF device under test.

[0061] See Figure 2 As shown, continuously increasing the input power of the RF device increases the vertical swing of the dynamic load line. When the upper limit of the swing reaches the SOA boundary of the RF device, the RF device will burn out. This point is defined as the boundary point of the RF device under this bias voltage. Figure 2 (The dots in the middle).

[0062] Further, in S103, the dynamic load line can be obtained by a dynamic load line tester. The dynamic load line tester is connected to the VCC / VDD power supply at one end and to the collector / drain of the radio frequency device at the other end, and can measure the voltage waveform and the current waveform on the output port of the radio frequency device. The voltage waveform and the current waveform are combined to obtain the dynamic load line of the output port.

[0063] In S104, S101-S103 are repeated to obtain the SOA boundary points under all preset bias voltages. Specifically, according to a preset test strategy, the preset bias voltage in S101 is modified to the next preset bias voltage to test the SOA boundary point under the preset bias voltage.

[0064] In the embodiment, the number and size of the preset bias voltages are defined according to the specifications of the radio frequency device. However, the preset bias voltage cannot exceed the maximum bias voltage, that is, cannot exceed the breakdown voltage from the output port to the ground of the radio frequency device. For GaAs HBT radio frequency devices and the like, the breakdown voltage from the output port to the ground is the breakdown voltage from the collector to the emitter. For GaAs PHEMT radio frequency devices or GaN HEMT radio frequency devices and the like, the breakdown voltage from the output port to the ground is the breakdown voltage from the drain to the source.

[0065] In the embodiment, the preset bias voltages can be output to the radio frequency device in ascending order. Specifically, as shown in FIG. 1, the boundary points of the SOA can be obtained from left to right, and the minimum preset bias voltage is used for initial testing. Figure 2

[0066] Figure 2 In FIG. 2, the solid line is the dynamic load line at the burnout power point, and the circle point is the upper limit of the swing range. By increasing the DC bias voltage, dynamic load lines at different positions (five are listed in FIG. 3) can be obtained. By connecting all the upper limits of the swing ranges of the dynamic load lines at the burnout power points (connecting the circle points), the SOA curve of the radio frequency device can be obtained. Figure 2

[0067] The present application adopts a radio frequency test method, controls the dynamic load line shape to be close to the vertical state through impedance, and increases the input power under different bias voltages to increase the swing range in the vertical direction and finally cause the device to burn out, so as to obtain a series of SOA boundary points of the radio frequency device in the real working state. By connecting all the SOA boundary points, the SOA curve of the radio frequency device can be obtained.

[0068] Further, before S105, the method further comprises:

[0069] outputting the maximum bias voltage and a certain bias current to the radio frequency device;

[0070] ​​setting a second impedance at the output end of the radio frequency device such that the dynamic load line of the output end of the radio frequency device approaches a horizontal state;

[0071] continuously increasing the input power of the radio frequency device to increase the swing of the dynamic load line in the horizontal direction, obtaining an upper limit of the swing at which the radio frequency device burns out, and taking the upper limit as the SOA boundary point.

[0072] The above steps are that when the collector / drain bias voltage of the radio frequency device approaches the breakdown voltage of the output end of the device to ground, if a larger SOA range is to be detected, the impedance values of the fundamental impedance, the second harmonic impedance and the third harmonic impedance are adjusted to make the dynamic load line of the device approach a horizontal state, the input power is increased to increase the swing of the dynamic load line in the horizontal direction, and when the upper limit of the swing in the horizontal direction reaches the SOA boundary of the device, the radio frequency device burns out, that is, the SOA boundary point under high bias voltage can be obtained. For details, see Figure 3 , wherein the maximum bias voltage can also be a set voltage.

[0073] In an embodiment, when the impedance values of the fundamental impedance, the second harmonic impedance and the third harmonic impedance are controlled to be greater than 500 ohms and the phase is 0°, that is, when it approaches an open circuit state (the greater the resistance, the closer the impedance to a complete open circuit), the dynamic load line can approach a horizontal state. When the dynamic load line approaches a horizontal state, the absolute value of the slope of the dynamic load line is less than 1 mA / V.

[0074] For details, see Figure 4 , which is a complete dynamic load line obtained by combining the dynamic load line in the vertical direction and the dynamic load line in the horizontal direction.

[0075] In summary, referring to Figure 5 , the overall process of the radio frequency device SOA extraction method based on the dynamic load line of the embodiment includes:

[0076] S401, outputting a preset bias voltage and a certain bias current to the radio frequency device;

[0077] S402, setting a first impedance at the output end of the radio frequency device such that the dynamic load line of the output end of the radio frequency device approaches a vertical state;

[0078] S403, continuously increasing the input power of the radio frequency device to increase the swing of the dynamic load line in the vertical direction, obtaining an upper limit of the swing at which the radio frequency device burns out, and taking the upper limit as the SOA boundary point;

[0079] S404, repeating S401-S403 to obtain the SOA boundary point under all preset bias voltages;

[0080] S405, outputting a maximum bias voltage and a certain bias current to the radio frequency device;

[0081] S406 setting a second impedance at the output end of the radio frequency device such that the dynamic load line of the output end of the radio frequency device approaches a horizontal state;

[0082] S407 continuously increasing the input power of the radio frequency device to increase the swing of the dynamic load line in the horizontal direction, obtaining an upper limit of the swing that causes the radio frequency device to burn out, and taking the upper limit of the swing as the SOA boundary point;

[0083] S408 connecting all SOA boundary points to obtain the SOA curve of the radio frequency device.

[0084] Referring to Figure 6 , a comparison diagram of the SOA curve extracted by the method of the present application and the SOA curve extracted by the direct current test of the prior art is shown. From Figure 6 , it can be seen that the SOA curve extracted by the method of the present application has a larger range than the SOA curve extracted by the direct current test of the prior art.

[0085] Referring to Figure 7 , a diagram of the relationship between the measured failure point one dynamic load line and the SOA curve extracted by the method of the present application (fundamental impedance = 0.818 ∠120) is shown. Referring to Figure 8 , a diagram of the relationship between the measured failure point two dynamic load line and the SOA curve extracted by the method of the present application (fundamental impedance = 0.818 ∠330) is shown.

[0086] By Figure 7 and Figure 8 , it can be seen that the SOA curve extracted by the present application is very close to the measured device burnout point, and the SOA curve obtained by the direct current test extraction method (original method) has a large difference from the actual burnout point of the radio frequency device due to the introduction of excessive direct current heat effect. It can be seen from this that the SOA curve extracted by the present embodiment can accurately reflect the true safe operating area range of the radio frequency device.

[0087] Referring to Figure 9 , as an implementation of the method shown in the above figures, the present application provides an embodiment of a radio frequency device SOA extraction system based on a dynamic load line, which corresponds to the method embodiments shown in Figure 1 or Figure 5 .

[0088] Specifically, a radio frequency device SOA extraction system based on a dynamic load line comprises a signal source 80, a power amplifier 81, a radio frequency device 82, a direct current bias module 83, a dynamic load line tester 85 and a load pulling module 86.

[0089] The signal source 80 is configured to output radio frequency power to the power amplifier 81.

[0090] The power amplifier 81 is used for amplifying the power of the signal source 80 and is connected with the input end of the radio frequency device 82;

[0091] The direct current bias module 83 is used for outputting preset bias voltage and bias current to the radio frequency device 82;

[0092] The dynamic load line tester 85 is used for collecting the voltage waveform and the current waveform on the output end of the radio frequency device 82, and combining the voltage waveform and the current waveform to output the dynamic load line;

[0093] The load traction module 86 is used for setting the impedance of the output end of the radio frequency device 82.

[0094] The above is only the specific embodiment of the present application, but the design concept of the present application is not limited to this, and any non-essential change of the present application using this concept should be considered as the infringement of the protection range of the present application.

[0095] The above is only the preferred embodiment of the present application, and it should be pointed out that, for ordinary skilled in the art, without departing from the principle of the present application, a number of improvements can be made, and these improvements should be considered as the protection range of the present application.

Claims

1. A dynamic load line based SOA extraction method for radio frequency devices, characterized in that, The method comprises: S101, outputting a preset bias voltage and a certain bias current to the radio frequency device; S102, setting a first impedance at the output end of the radio frequency device to make the dynamic load line of the output end of the radio frequency device close to a vertical state; S103, continuously increasing the input power of the radio frequency device to increase the swing of the dynamic load line in the vertical direction, obtaining an upper limit of the swing that makes the radio frequency device burn out, and taking the upper limit as a SOA boundary point; S104, repeating S101-S103 to obtain SOA boundary points under all preset bias voltages; S105, connecting all SOA boundary points to obtain the SOA curve of the radio frequency device.

2. The dynamic load line based SOA extraction method for radio frequency devices of claim 1, wherein, Before S105, the method further comprises: outputting a maximum bias voltage and a certain bias current to the radio frequency device; setting a second impedance at the output end of the radio frequency device to make the dynamic load line of the output end of the radio frequency device close to a horizontal state; continuously increasing the input power of the radio frequency device to increase the swing of the dynamic load line in the horizontal direction, obtaining an upper limit of the swing that makes the radio frequency device burn out, and taking the upper limit as a SOA boundary point.

3. The dynamic load line based SOA extraction method for radio frequency devices of claim 1, wherein, The first impedance comprises a fundamental wave impedance, a second harmonic wave impedance and a third harmonic wave impedance.

4. The dynamic load line based SOA extraction method for radio frequency devices of claim 2, wherein, The second impedance comprises a fundamental wave impedance, a second harmonic wave impedance and a third harmonic wave impedance.

5. The dynamic load line based SOA extraction method for radio frequency devices of claim 1, wherein, The number and size of the preset bias voltages are defined according to the specifications of the radio frequency device.

6. The dynamic load line based SOA extraction method for radio frequency devices of claim 2, wherein, The preset bias voltage is smaller than the maximum bias voltage, and the maximum bias voltage is close to the breakdown voltage of the output end of the radio frequency device to ground.

7. The dynamic load line based SOA extraction method for radio frequency devices of claim 1, wherein, The preset bias voltages are output to the radio frequency device in order from small to large.

8. The dynamic load line based SOA extraction method for radio frequency devices of claim 1, wherein, The S101 specifically comprises: outputting a preset bias voltage to the output end of the radio frequency device and outputting a certain bias current to the input end of the radio frequency device.

9. The dynamic load line based SOA extraction method for radio frequency devices of claim 8, wherein, The radio frequency device comprises a GaAs radio frequency device or a GaN radio frequency device; when the radio frequency device is a GaAs PHEMT radio frequency device or a GaN HEMT radio frequency device, the input end is a gate and the output end is a drain; when the radio frequency device is a GaAs HBT radio frequency device, the input end is a base and the output end is a collector.

10. A dynamic load line based SOA extraction system for radio frequency devices, comprising: Based on the method of any one of claims 1-9, comprising: a signal source, a power amplifier, a radio frequency device, a direct current bias module, a dynamic load line tester and a load traction module; The signal source is configured to output radio frequency power to the power amplifier; The power amplifier is configured to amplify the power input by the signal source and connect the amplified power to the input end of the radio frequency device; The direct current bias module is configured to output a preset bias voltage and a bias current to the radio frequency device; The dynamic load line tester is configured to collect voltage and current waveforms on the output end of the radio frequency device, and combine the voltage and current waveforms to output a dynamic load line; The load traction module is configured to set the impedance of the output end of the radio frequency device.

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