External direct-current bias device for network analyzer and test method of external direct-current bias device

Abstract

The invention provides an external direct current bias device for a network analyzer and a test method thereof, and relates to the technical field of direct current bias, the external direct current bias device for the network analyzer comprises a test device, a tested device and an external direct current bias circuit; the external direct current bias circuit is arranged between the test equipment and the tested device; direct current bias supply and high-frequency test signal transmission control are carried out on the test equipment and the tested device through the external direct current bias circuit, the performance of the test equipment can be remarkably improved through the external direct current bias circuit, and the test intelligence and precision level of devices such as a signal inductor and the like is enhanced.

Description

Technical Field

[0001] This invention proposes an external DC bias device for network analyzers and its testing method, relating to the field of DC bias technology, specifically to the field of external DC bias for network analyzers. Background Technology

[0002] In the field of electronic measurement, network analyzers and other testing equipment are widely used to measure the performance parameters of electronic components such as signal inductors and filters. Signal inductors and similar devices play a crucial role in high-frequency signal transmission, and their performance directly affects the signal quality of the circuit. Providing a stable DC bias to the device under test (DUT) is essential for ensuring the accuracy of the test results. However, existing testing equipment often cannot directly provide a suitable DC bias for signal inductors or similar devices, or the provided DC bias circuits suffer from insufficient stability and susceptibility to interference. Summary of the Invention

[0003] This invention provides an external DC bias device for network analyzers and its testing method to solve the above-mentioned problems:

[0004] This invention proposes an external DC bias device for a network analyzer and its testing method. The external DC bias device for a network analyzer includes a testing device, a device under test, and an external DC bias circuit.

[0005] The external DC bias circuit is positioned between the test equipment and the device under test.

[0006] An external DC bias circuit is used to supply DC bias to the test equipment and the device under test, and to control the transmission of high-frequency test signals.

[0007] Furthermore, the external DC bias circuit includes a DC filter network, a bias path signal isolation module, and a connection interface module;

[0008] The first electrical signal input terminal of the connection interface module is the electrical signal input terminal of the external DC bias circuit. The first electrical signal output terminal of the connection interface module is connected to the electrical signal input terminal of the DC filter network. The electrical signal output terminal of the DC filter network is connected to the electrical signal input terminal of the bias path signal isolation module. The electrical signal output terminal of the bias path signal isolation module is connected to the second electrical signal input terminal of the connection interface module. The second electrical signal output terminal of the connection interface module is the electrical signal output terminal of the external DC bias circuit.

[0009] Furthermore, the DC filter network includes a high-frequency filter capacitor, a low-frequency filter capacitor, and a high-frequency choke inductor. Two sets of π-type filter networks are formed by the high-frequency filter capacitor, the low-frequency filter capacitor, and the high-frequency choke inductor to filter out abnormal noise and ripple.

[0010] Furthermore, the bias path signal isolation module includes an RF isolation inductor and a DC blocking capacitor. An RF isolation inductor group is constructed through the RF isolation inductor, and the RF isolation inductor group combined with the DC blocking capacitor supplies electrical signals to the device under test, while simultaneously blocking high-frequency crosstalk to the connection interface module.

[0011] Furthermore, the connection interface module includes a DC power interface and a test port;

[0012] The DC power interface includes a high-reliability DC connector, and the test port includes an RF coaxial connector.

[0013] Furthermore, the method includes:

[0014] S1. Input the DC power supply to the DC power supply interface. The DC power supply interface inputs the DC power supply to the π-type filter network. The DC power supply is purified by the π-type filter network to obtain the DC bias current / voltage.

[0015] S2. The DC bias current / voltage is transmitted to the EUT through the radio frequency isolation inductor to provide working bias to the EUT and obtain working bias supply information.

[0016] S3. Obtain high-frequency test signals through the test port connector, isolate DC bias through DC blocking capacitor, transmit high-frequency test signals to EUT, and then obtain the high-frequency test signals after operation and output them to the test equipment.

[0017] S4. Obtain the filtering operation data of the π-type filter network, perform filtering operation analysis based on the filtering operation data, and obtain the filtering operation analysis results; obtain the inductance operation data of the RF isolation inductor, perform inductance operation analysis based on the inductance operation data, and obtain the inductance operation analysis results; perform device effect testing and judgment based on the filtering operation analysis results and the inductance operation analysis results, and obtain device test judgment data.

[0018] Further, S3 includes:

[0019] High-frequency test signals from the network analyzer are obtained through the test port connector;

[0020] The high-frequency test signal is isolated from DC by a DC blocking capacitor and then input into the EUT. The EUT outputs the DC-isolated high-frequency test signal to another DC blocking capacitor.

[0021] Transmitted to another test port connector via another DC blocking capacitor;

[0022] The isolated DC high-frequency test signal is output to the test equipment through another test port connector.

[0023] Furthermore, the step of acquiring the filtering operation data of the π-type filter network, performing filtering operation analysis based on the filtering operation data, and obtaining the filtering operation analysis results includes:

[0024] Input and output data are acquired for the π-type filter network to obtain filter input acquisition data and filter output acquisition data;

[0025] The filtered input data is compared with a preset abnormal data threshold to obtain the abnormal filtering comparison result.

[0026] Obtain the abnormal input data of the filter based on the filter anomaly comparison results;

[0027] Obtain the ratio of the filtered input abnormal data to the preset filtered abnormal data threshold to obtain the filtered input abnormal coefficient;

[0028] Obtain the filter output anomaly coefficient from the collected filter output data;

[0029] Calculate the difference between the abnormal coefficients of the filter input and the abnormal coefficients of the filter output to obtain the filter difference data;

[0030] The filtering process is determined based on the filtering difference data, and the filtering analysis results are obtained.

[0031] Furthermore, the step of acquiring the inductor operating data of the RF isolation inductor, performing inductor operating analysis based on the inductor operating data, and obtaining the inductor operating analysis results includes:

[0032] Input and output data are acquired from the RF isolation inductor to obtain inductor input acquisition data and inductor output acquisition data.

[0033] The inductor input data is compared with a preset inductor abnormal data threshold to obtain the inductor abnormality comparison result.

[0034] Obtain inductor input anomaly data based on the inductor anomaly comparison results;

[0035] The ratio of abnormal inductor input data to a preset abnormal inductor input data threshold is used to obtain the inductor input abnormality coefficient.

[0036] Acquire the inductor output anomaly coefficient from the inductor output acquisition data;

[0037] Calculate the difference between the inductor input abnormality coefficient and the inductor output abnormality coefficient to obtain the inductor difference data;

[0038] The inductor's operation is determined based on the inductance difference data, and the inductor's operation analysis results are obtained.

[0039] Furthermore, the step of testing and judging the device performance based on the filtering operation analysis results and the inductor operation analysis results to obtain device test and judgment data includes:

[0040] When both the filter operation analysis result and the inductor operation analysis result are deemed as qualified, the device test is deemed qualified.

[0041] When at least one of the filter operation analysis results and the inductor operation analysis results is deemed as an unqualified operation, the device test is deemed unqualified.

[0042] When the device test judgment data indicates that the device test is unqualified, the test parameters are adjusted until the device test judgment data indicates that the device test is qualified.

[0043] The beneficial effects of this invention are as follows: The external DC bias circuit provides a stable and accurate DC bias for test equipment, which is of significant practical importance; it supports a wide range of voltage adjustment from low to high voltage, meeting the needs of different devices under test. Through novel filtering and voltage regulation technologies, the stability of the DC bias is significantly improved, reducing test errors caused by power supply fluctuations and interference.

[0044] Through a feedback adjustment mechanism, the DC bias voltage can be precisely adjusted to meet the requirements of high-precision testing. Shielding technology and electromagnetic compatibility design effectively suppress external interference, ensuring the accuracy of test results. The modular design makes the circuit easy to adjust and expand, adapting to the needs of different testing scenarios. This invention's external DC bias circuit can significantly improve the performance of testing equipment, providing more reliable support for the testing of signal inductors and other devices. Attached Figure Description

[0045] Figure 1 A schematic diagram of an external DC bias device for a network analyzer and its testing method;

[0046] Figure 2 This is a schematic diagram of a high-frequency isolated, high-stability DC bias circuit. Detailed Implementation

[0047] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0048] In one embodiment of the present invention, an external DC bias device for a network analyzer and its testing method are provided. The external DC bias device for the network analyzer includes a testing device, a device under test, and an external DC bias circuit.

[0049] The external DC bias circuit is positioned between the test equipment and the device under test.

[0050] An external DC bias circuit is used to supply DC bias to the test equipment and the device under test, and to control the transmission of high-frequency test signals.

[0051] The working principle and technical effects of the above technical solution are as follows: The external DC bias circuit of this invention is mainly applied to high-frequency, high-precision testing scenarios of electronic test equipment such as network analyzers. It provides a stable DC bias for the device under test (EUT, such as signal inductors, filters, high-frequency active devices, etc.) while achieving isolated transmission of high-frequency test signals and DC bias. Test equipment, such as vector network analyzers, is used for high-precision measurement of the RF / high-frequency electrical performance parameters (such as S-parameters, impedance, etc.) of the EUT. The EUT includes electronic components requiring DC bias, such as signal inductors, RF filters, and microwave active chips. The external DC bias circuit is an independent module connected between the test equipment and the EUT, achieving stable DC bias supply and distortion-free transmission of high-frequency test signals. It is suitable for high-frequency scenarios such as millimeter waves and microwaves, improving test accuracy and stability.

[0052] This invention addresses the following technical problems encountered by existing DC bias circuits in testing equipment: limited output voltage range, failing to meet the needs of different devices under test; insufficient anti-interference capability, leading to unstable DC bias and affecting the accuracy of test results; lack of fine adjustment capability, making high-precision testing difficult; and insufficient flexibility, making it difficult to adapt to the needs of different testing scenarios. These problems limit the application of existing DC bias circuits in high-precision testing. The external DC bias circuit of this invention provides a wide-range, high-precision, and highly stable DC bias to meet the actual needs of testing equipment.

[0053] like Figure 2 As shown, the connection relationships, component models and parameters of the DC power supply interface, filter capacitor, choke / isolation inductor, DC blocking capacitor, test port and EUT are clearly presented, demonstrating the circuit topology and signal transmission mechanism.

[0054] The external DC bias circuit of this invention achieves high stability of DC bias, low loss transmission of high-frequency signals, and high isolation of multiple ports in high-frequency scenarios, providing reliable hardware support for network analyzers to perform high-precision testing of electronic devices.

[0055] This device uses an external DC bias circuit as its core intermediate module, precisely deployed between the test equipment and the device under test (DUT), forming a bidirectional functional link: the DC bias circuit receives external DC power input, processes it internally, and provides a stable DC bias to the DUT, ensuring its normal operation; through internal isolation and transmission control mechanisms, it achieves precise transmission of the high-frequency test signal output from the test equipment to the DUT, while simultaneously blocking mutual interference between the DC bias and the high-frequency test signal, ensuring that the two types of signals are transmitted independently in their respective links. The test equipment (such as a vector network analyzer) then uses this architecture to measure the RF / high-frequency electrical performance parameters of the DUT with a stable bias, completing a high-precision test process.

[0056] It solves the technical problems of existing DC bias circuits, such as limited output voltage range, insufficient anti-interference capability, lack of fine adjustment capability, and poor flexibility; it achieves the dual goals of stable DC bias supply and isolated transmission of high-frequency test signals in high-frequency and high-precision testing scenarios; it improves the adaptability (meeting the needs of different devices under test), stability (suppressing power fluctuations and electromagnetic interference), and testing accuracy (avoiding measurement deviations caused by signal interference); it enhances the circuit's adaptability to different testing scenarios and breaks the limitations of existing technologies in high-precision testing applications.

[0057] In one embodiment of the present invention, the external DC bias circuit includes a DC filter network, a bias path signal isolation module, and a connection interface module;

[0058] The first electrical signal input terminal of the connection interface module is the electrical signal input terminal of the external DC bias circuit. The first electrical signal output terminal of the connection interface module is connected to the electrical signal input terminal of the DC filter network. The electrical signal output terminal of the DC filter network is connected to the electrical signal input terminal of the bias path signal isolation module. The electrical signal output terminal of the bias path signal isolation module is connected to the second electrical signal input terminal of the connection interface module. The second electrical signal output terminal of the connection interface module is the electrical signal output terminal of the external DC bias circuit.

[0059] The DC filter network includes a high-frequency filter capacitor, a low-frequency filter capacitor, and a high-frequency choke inductor. Two sets of π-type filter networks are formed by the high-frequency filter capacitor, the low-frequency filter capacitor, and the high-frequency choke inductor to filter out abnormal noise and ripple.

[0060] The bias path signal isolation module includes an RF isolation inductor and a DC blocking capacitor. An RF isolation inductor group is constructed through the RF isolation inductor, and the RF isolation inductor group combined with the DC blocking capacitor supplies electrical signals to the device under test, while blocking high-frequency crosstalk of the connection interface module.

[0061] The connection interface module includes a DC power interface and a test port;

[0062] The DC power interface includes a high-reliability DC connector, and the test port includes an RF coaxial connector.

[0063] The working principle and technical effects of the above technical solution are as follows: The DC filter network of this invention includes two sets of π-type filter circuits composed of C5 (100nF), L1 (BPLSA0603-470M), C6 (20μF), C7 (100nF), L2 (BPLSA0603-470M), and C8 (20μF) to achieve dual-stage noise suppression and filter out high-frequency interference and low-frequency ripple of the DC power supply. The RF isolation and DC path include L3, L4, L5, and L6 (BPLAA201610-2R2M) forming an RF isolation inductor group, which, together with DC blocking capacitors C1, C2, C3, and C4, achieves a stable DC bias supply to the device under test, while blocking high-frequency crosstalk between NET1, NET2 and NET3, NET4. The connectors include a high-reliability DC connector for the DC power interface and an RF coaxial connector (SMA connector, supporting 26GHz transmission) for the test ports (NET1, etc.) to ensure stable signal and power transmission.

[0064] The DC power interface (DC_SOURCE) connects to an external stable DC power supply, providing DC bias voltage. Filter capacitors, including high-frequency filter capacitors (e.g., C5, C7, 100nF) and low-frequency filter capacitors (e.g., C6, C8, 20μF), form a π-type filter network to filter out high-frequency noise and low-frequency ripple from the power supply. High-frequency choke inductors, such as L1 and L2 (BPLSA0603-470M), block high-frequency test signals from entering the DC power supply circuit, ensuring stable DC bias transmission. RF isolation inductors, such as L3, L4, L5, and L6 (BPLAA201610-2R2M), isolate high-frequency crosstalk between test ports while providing a path for DC bias. DC blocking capacitors, such as C1, C2, C3, and C4, isolate DC bias from high-frequency test signals, ensuring that test signals are transmitted only between the test port and the device under test. Connectors include DC power connectors and test port connectors (NET1, NET2, NET3, NET4), enabling reliable connections to external devices and components, such as… Figure 2 As shown.

[0065] This device breaks down the external DC bias circuit into three functional units: a DC filter network, a bias path signal isolation module, and a connection interface module. The modules work collaboratively through clearly defined electrical signal links: the connection interface module acts as a bridge between the circuit and external devices. Its first electrical signal input terminal receives external DC power, which is then transmitted to the DC filter network via its first electrical signal output terminal. The DC filter network uses two sets of π-type filter networks—a high-frequency filter capacitor, a low-frequency filter capacitor, and a high-frequency choke inductor—to filter out noise and ripple from the input DC power. The purified DC signal is then transmitted to the bias path signal isolation module. The bias path signal isolation module, through the cooperation of an RF isolation inductor group and a DC blocking capacitor, constructs a DC conduction and high-frequency blocking path, transmitting the purified DC bias to the second electrical signal input terminal of the connection interface module, and then to the device under test (DUT) via the second electrical signal output terminal. Simultaneously, the test ports of the connection interface module enable the input and output of high-frequency test signals, while the bias path signal isolation module synchronously blocks high-frequency crosstalk between the test ports. The DC power interface of the connection module uses a high-reliability DC connector to ensure stable power input, and the test port uses an RF coaxial connector to ensure low-loss transmission of high-frequency signals.

[0066] It solves the technical problems of existing circuit module division, chaotic signal transmission links, weak anti-interference ability, and large signal loss; it realizes the modular decomposition and coordination of the external DC bias circuit function, clarifies the core responsibilities and signal transmission paths of each module; it improves the purification effect of DC power supply (two-stage filtering effectively filters out high and low frequency interference), the isolation performance of high frequency signals (blocking crosstalk between ports), and the stability of signal transmission (dedicated connectors ensure connection reliability); it reduces the difficulty of circuit fault diagnosis (modular design facilitates problem location) and signal transmission loss, and enhances the maintainability and scalability of the circuit.

[0067] The DC filter network employs two sets of symmetrical π-type filter circuits (C5, L1, C6, C7, L2, C8). A high-frequency filter capacitor (100nF) removes high-frequency noise from the DC power supply, while a low-frequency filter capacitor (20μF) removes low-frequency ripple. A high-frequency choke inductor (BPLSA0603-470M) blocks high-frequency test signals from entering the DC power supply circuit in reverse. This dual-stage filtering achieves deep purification of the DC power supply. The bias path signal isolation module uses an RF isolation inductor group (L3, L6, BPLAA201610-2R2M) in conjunction with a DC blocking capacitor (C1, L2, C8). C4), the RF isolation inductor group provides a conduction path for DC bias while suppressing high-frequency crosstalk between test ports (NET1, NET2 and NET3, NET4), and the DC blocking capacitor isolates DC bias from high-frequency test signals, ensuring that high-frequency test signals are transmitted only between the test port and the device under test; the DC power interface of the connection interface module uses a high-reliability DC connector to ensure stable power input, and the test port uses an SMA RF coaxial connector (supporting 26GHz transmission) to ensure wide-band low-loss transmission of high-frequency signals. All components are connected through precise topology to form a complete functional circuit.

[0068] This solution addresses existing technical issues such as poor purification effect of filter circuits, insufficient crosstalk suppression capability of isolation circuits, narrow high-frequency signal transmission band, and high signal loss. It achieves two-stage deep purification of DC power supply, efficient isolation between high-frequency test signals and DC bias, and stable transmission of wide-band high-frequency signals. It improves the purity of DC bias (completely filtering out high and low frequency interference), the isolation between ports (suppressing crosstalk), and the frequency band adaptability of the circuit (supporting low-frequency to millimeter-wave frequency band testing). It reduces high-frequency signal transmission loss and test signal interference, ensuring that the device under test obtains a stable bias while guaranteeing the integrity of the high-frequency test signal, further improving test accuracy and circuit versatility.

[0069] In one embodiment of the present invention, the method includes:

[0070] S1. Input the DC power supply to the DC power supply interface. The DC power supply interface inputs the DC power supply to the π-type filter network. The DC power supply is purified by the π-type filter network to obtain the DC bias current / voltage.

[0071] S2. The DC bias current / voltage is transmitted to the EUT through the radio frequency isolation inductor to provide working bias to the EUT and obtain working bias supply information.

[0072] S3. Obtain high-frequency test signals through the test port connector, isolate DC bias through DC blocking capacitor, transmit high-frequency test signals to EUT, and then obtain the high-frequency test signals after operation and output them to the test equipment.

[0073] S4. Obtain the filtering operation data of the π-type filter network, perform filtering operation analysis based on the filtering operation data, and obtain the filtering operation analysis results; obtain the inductance operation data of the RF isolation inductor, perform inductance operation analysis based on the inductance operation data, and obtain the inductance operation analysis results; perform device effect testing and judgment based on the filtering operation analysis results and the inductance operation analysis results, and obtain device test judgment data.

[0074] The purpose of DC bias is to provide a DC bias to the EUT (i.e., high-frequency filtering devices, such as common-mode inductors / ferrite beads), and to observe the S-parameter effects of the EUT (i.e., high-frequency filtering devices, such as common-mode inductors / ferrite beads) after applying a large current (simulating the actual application of devices in product circuits).

[0075] When testing the S-parameters of an EUT using a network analyzer under normal circumstances, the electrical signal provided by the network analyzer is relatively weak (usually in the μA or mA range). However, the devices used in actual circuits are generally in the A range. Many filter devices contain ferrite material, which will saturate when a large current is applied, resulting in a reduction in the actual filtering effect of the device. Therefore, it is necessary to apply voltage and current to the device and observe the S-parameters after the reduction.

[0076] The above scheme provides a high-current DC bias to the EUT (Electronic Under Test Device), simulating the saturation phenomenon of ferrite material under actual operating conditions. It tests the S-parameters of the EUT under bias conditions to verify the attenuation of the filtering effect. The core of the scheme is DC bias supply, high-frequency test signal transmission, and operating status determination, with the aim of obtaining the performance data of the EUT under DC bias.

[0077] By purifying the DC power supply through a π-type filter network and then transmitting it to the EUT via an RF isolation inductor, a stable supply of high-current DC bias is achieved. At the same time, the RF isolation inductor avoids interference from the DC circuit to the high-frequency test signal, which directly corresponds to the requirement of applying voltage and current to the EUT.

[0078] By isolating the DC bias and high-frequency test signal with a DC blocking capacitor, the high-frequency signal (weak current) of the network analyzer is independently transmitted to the EUT, and the final output test signal is used for S-parameter analysis. This solves the technical problem of "coexistence of weak current test signal and high current DC bias" and fully matches the requirements of S-parameter under test bias conditions.

[0079] Analyzing the operating data of the π-type filter network and RF isolation inductor is to ensure the stability and accuracy of the DC bias supply. Only when the filter network and inductor are working properly can the DC bias applied to the EUT be guaranteed to be a large current that conforms to the actual operating conditions, avoiding test errors caused by device malfunctions. This is a necessary prerequisite for ensuring the validity of test results.

[0080] The working principle and technical effect of the above technical solution are as follows: After the DC power supply is input through DC_SOURCE, it is purified by a π-type filter network to form a stable DC bias; the DC bias is transmitted to the EUT through L3, L4, L5, and L6 to provide it with a working bias; the high-frequency test signal of the network analyzer is input through NET1 and NET2, and after being isolated by C1 and C3, it enters the EUT, and after being isolated by C2 and C4, it is output to the test equipment through NET3 and NET4; L1 and L2 block the leakage of high-frequency signals to the DC power supply, and L3 and L6 suppress crosstalk at the test port, ultimately achieving independent transmission and efficient isolation of the DC bias and the high-frequency test signal.

[0081] In this method, the external DC power supply is input through the DC power interface and then enters the π-type filter network for noise and ripple filtering, completing the DC power supply purification process and generating a stable DC bias current / voltage. The purified DC bias current / voltage is transmitted to the device under test (EUT) through an RF isolation inductor, providing a stable operating bias for the EUT and ensuring that the EUT is in normal working condition. The high-frequency test signal of the test equipment is acquired through the test port connector and then the DC bias component is isolated by a DC blocking capacitor, transmitting only the high-frequency test signal to the EUT. After being processed by the EUT, the high-frequency test signal is again isolated by a DC blocking capacitor before being output to the test equipment. By collecting the input and output operating data of the π-type filter network and the RF isolation inductor, filtering operation analysis and inductor operation analysis are performed respectively. The results of the two types of analysis are then combined to test and judge the overall working effect of the device, generating device test judgment data.

[0082] This method solves the technical problems of incomplete workflow, lack of systematic performance judgment mechanism, and easy mutual interference between DC bias and high-frequency signal in existing devices; it realizes stable DC bias supply, interference-free transmission of high-frequency test signals, and accurate judgment of device performance; it improves the standardization (process design), reliability (performance judgment to ensure working status), and test accuracy of device operation (signal isolation to avoid interference); and it reduces test errors caused by the device's own performance problems.

[0083] In one embodiment of the present invention, S3 includes:

[0084] High-frequency test signals from the network analyzer are obtained through the test port connector;

[0085] The high-frequency test signal is isolated from DC by a DC blocking capacitor and then input into the EUT. The EUT outputs the DC-isolated high-frequency test signal to another DC blocking capacitor.

[0086] Transmitted to another test port connector via another DC blocking capacitor;

[0087] The isolated DC high-frequency test signal is output to the test equipment through another test port connector.

[0088] The working principle and technical effect of the above technical solution are as follows: This method accurately acquires the high-frequency test signal output by the network analyzer through the test port connector, ensuring the reliability of the signal transmission start point; the high-frequency test signal is input to the first DC blocking capacitor, and through the DC blocking capacitor's DC blocking and AC passing characteristics, the DC bias component in the signal is isolated, avoiding DC interference to the high-frequency test signal; the high-frequency test signal after DC isolation is input to the device under test (EUT), completing the EUT's action on the high-frequency signal; the high-frequency test signal after action is output to the second DC blocking capacitor for secondary DC isolation, further removing any residual DC components in the signal and ensuring signal purity; the high-frequency test signal after secondary DC isolation is output to the test equipment through another test port connector, completing the complete transmission link of the high-frequency test signal.

[0089] This method solves the technical problems of incomplete DC bias isolation, ambiguous signal transmission links, and insufficient signal purity in existing high-frequency signal transmission processes; it achieves precise DC isolation and interference-free transmission of high-frequency test signals during transmission; it improves the integrity and purity of high-frequency test signals (ensuring secondary isolation) and the controllability of the transmission link (refined steps facilitate management); it reduces the interference of DC bias on high-frequency test signals, avoids test result deviations caused by signal contamination, and further ensures the accuracy of network analyzer measurements of EUT high-frequency electrical performance parameters.

[0090] In one embodiment of the present invention, the step of acquiring filtering operation data of a π-type filter network, performing filtering operation analysis based on the filtering operation data, and obtaining filtering operation analysis results includes:

[0091] Input and output data are acquired for the π-type filter network to obtain filter input acquisition data and filter output acquisition data;

[0092] The filtered input data is compared with a preset abnormal data threshold to obtain the abnormal filtering comparison result.

[0093] Obtain the abnormal input data of the filter based on the filter anomaly comparison results;

[0094] Obtain the ratio of the filtered input abnormal data to the preset filtered abnormal data threshold to obtain the filtered input abnormal coefficient;

[0095] Obtain the filter output anomaly coefficient from the collected filter output data;

[0096] Calculate the difference between the abnormal coefficients of the filter input and the abnormal coefficients of the filter output to obtain the filter difference data;

[0097] The filtering process is determined based on the filtering difference data, and the filtering analysis results are obtained.

[0098] The working principle and technical effect of the above technical solution are as follows: This method collects data at the input and output ends of the π-type filter network to obtain filter input data (raw DC power supply data) and filter output data (purified DC data); the filter input data is compared with a preset abnormal filter data threshold to filter out abnormal filter input data that exceeds the threshold range; the ratio of the abnormal input data to the preset threshold is calculated to obtain the filter input abnormal coefficient, and the filter output abnormal coefficient is obtained similarly; the difference between the input abnormal coefficient and the output abnormal coefficient is calculated to obtain the filter difference data; finally, the filtering working state of the π-type filter network is determined according to the sign of the filter difference data, and the filtering working analysis result is generated.

[0099] This method solves the technical problems of existing filter performance analysis methods, such as strong subjectivity, unclear judgment criteria, and inability to accurately quantify the filtering effect; it realizes the objective and accurate analysis and judgment of the working performance of π-type filter networks; it improves the scientificity (quantization coefficient calculation), accuracy (input-output comparison), and reliability (threshold-based judgment) of filter performance judgment; it reduces the problem of DC bias instability caused by the failure to detect poor filtering effect in time, provides a pre-performance guarantee for the stable supply of DC bias, and indirectly improves the testing accuracy of the entire device.

[0100] In one embodiment of the present invention, the step of acquiring the inductor operating data of the radio frequency isolation inductor, performing inductor operating analysis based on the inductor operating data, and obtaining the inductor operating analysis result includes:

[0101] Input and output data are acquired from the RF isolation inductor to obtain inductor input acquisition data and inductor output acquisition data.

[0102] The inductor input data is compared with a preset inductor abnormal data threshold to obtain the inductor abnormality comparison result.

[0103] Obtain inductor input anomaly data based on the inductor anomaly comparison results;

[0104] The ratio of abnormal inductor input data to a preset abnormal inductor input data threshold is used to obtain the inductor input abnormality coefficient.

[0105] Acquire the inductor output anomaly coefficient from the inductor output acquisition data;

[0106] Calculate the difference between the inductor input abnormality coefficient and the inductor output abnormality coefficient to obtain the inductor difference data;

[0107] The inductor's operation is determined based on the inductance difference data, and the inductor's operation analysis results are obtained.

[0108] The working principle and technical effect of the above technical solution are as follows: This method acquires data from the input and output terminals of the RF isolation inductor to obtain inductor input acquisition data (signal / energy data input to the inductor) and inductor output acquisition data (signal / energy data transmitted through the inductor); the inductor input acquisition data is compared with a preset inductor abnormal data threshold to determine the inductor input abnormal data; the ratio of the input abnormal data to the preset threshold is calculated to obtain the inductor input abnormal coefficient, and the inductor output abnormal coefficient is obtained simultaneously; the difference between the input abnormal coefficient and the output abnormal coefficient is calculated to obtain the inductor difference data; the working state of the RF isolation inductor is determined based on the inductor difference data, and the inductor working analysis results are generated to achieve accurate evaluation of the inductor isolation performance and conduction performance.

[0109] This invention addresses the technical challenges of lacking a unified standard for performance analysis of RF isolation inductors, failing to accurately identify isolation / conduction anomalies, and having low reliability of analysis results. It enables quantitative analysis and accurate determination of the operating performance of RF isolation inductors, improves the consistency (from the same logic as filter analysis), scientific rigor (quantization coefficients), and effectiveness (input-output comparison) of inductor performance determination, and reduces signal crosstalk and unstable bias transmission caused by inductor isolation failure or conduction anomalies, thus ensuring the core functionality of the bias path signal isolation module.

[0110] In one embodiment of the present invention, the step of performing device performance testing and judgment based on the filtering operation analysis results and the inductor operation analysis results to obtain device test judgment data includes:

[0111] When both the filter operation analysis result and the inductor operation analysis result are deemed as qualified, the device test is deemed qualified.

[0112] When at least one of the filter operation analysis results and the inductor operation analysis results is deemed as an unqualified operation, the device test is deemed unqualified.

[0113] When the device test judgment data indicates that the device test is unqualified, the test parameters are adjusted until the device test judgment data indicates that the device test is qualified.

[0114] The working principle and technical effect of the above technical solution are as follows: This method uses the filter operation analysis results and the inductor operation analysis results as the core judgment criteria. It adopts the judgment principle of "all qualified means qualified". When both types of analysis results are qualified, the device test is directly judged to be qualified. It adopts the principle of "one unqualified means unqualified". When at least one of the two types of analysis results is unqualified, the device test is judged to be unqualified. For the unqualified judgment results, the test parameter adjustment mechanism is activated. By adjusting the filter network parameters (such as capacitance / inductance values), inductor operation parameters and other key parameters, the performance analysis and judgment are re-performed until the device test results reach the qualified standard, forming a closed-loop control of judgment, optimization and re-judgment.

[0115] This method solves the technical problems of existing devices, such as ambiguous overall performance judgment logic, lack of clear judgment standards, and lack of effective optimization mechanisms for unqualified states. It achieves accurate and rapid judgment of the overall working effect of the device and effective correction of unqualified states. It improves the reliability (qualified judgment ensures working state), maintainability (optimization mechanism clarifies adjustment direction), and ease of use (closed-loop control eliminates the need for component replacement). It reduces test failures and errors caused by substandard device performance, ensures that the device can continuously and stably adapt to high-frequency and high-precision testing requirements, and improves the practicality and market adaptability of the device.

[0116] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. An external DC bias device for a network analyzer, characterized in that, The external DC bias device for the network analyzer includes a test device, a device under test, and an external DC bias circuit; The external DC bias circuit is positioned between the test equipment and the device under test. An external DC bias circuit is used to supply DC bias to the test equipment and the device under test, and to control the transmission of high-frequency test signals.

2. The external DC bias device for a network analyzer according to claim 1, characterized in that, The external DC bias circuit includes a DC filter network, a bias path signal isolation module, and a connection interface module; The first electrical signal input terminal of the connection interface module is the electrical signal input terminal of the external DC bias circuit. The first electrical signal output terminal of the connection interface module is connected to the electrical signal input terminal of the DC filter network. The electrical signal output terminal of the DC filter network is connected to the electrical signal input terminal of the bias path signal isolation module. The electrical signal output terminal of the bias path signal isolation module is connected to the second electrical signal input terminal of the connection interface module. The second electrical signal output terminal of the connection interface module is the electrical signal output terminal of the external DC bias circuit.

3. The external DC bias device for a network analyzer according to claim 2, characterized in that, The DC filter network includes a high-frequency filter capacitor, a low-frequency filter capacitor, and a high-frequency choke inductor. Two sets of π-type filter networks are formed by the high-frequency filter capacitor, the low-frequency filter capacitor, and the high-frequency choke inductor to filter out abnormal noise and ripple.

4. The external DC bias device for a network analyzer according to claim 2, characterized in that, The bias path signal isolation module includes an RF isolation inductor and a DC blocking capacitor. An RF isolation inductor group is constructed through the RF isolation inductor, and the RF isolation inductor group combined with the DC blocking capacitor supplies electrical signals to the device under test, while blocking high-frequency crosstalk of the connection interface module.

5. The external DC bias device for a network analyzer according to claim 2, characterized in that, The connection interface module includes a DC power interface and a test port; The DC power interface includes a high-reliability DC connector, and the test port includes an RF coaxial connector.

6. A test method for an external DC bias device for a network analyzer, characterized in that, The method includes: S1. Input the DC power supply to the DC power supply interface. The DC power supply interface inputs the DC power supply to the π-type filter network. The DC power supply is purified by the π-type filter network to obtain the DC bias current / voltage. S2. The DC bias current / voltage is transmitted to the EUT through the radio frequency isolation inductor to provide working bias to the EUT and obtain working bias supply information. S3. Obtain high-frequency test signals through the test port connector, isolate DC bias through DC blocking capacitor, transmit high-frequency test signals to EUT, and then obtain the high-frequency test signals after operation and output them to the test equipment. S4. Obtain the filtering operation data of the π-type filter network, perform filtering operation analysis based on the filtering operation data, and obtain the filtering operation analysis results; obtain the inductance operation data of the RF isolation inductor, perform inductance operation analysis based on the inductance operation data, and obtain the inductance operation analysis results; perform device effect testing and judgment based on the filtering operation analysis results and the inductance operation analysis results, and obtain device test judgment data.

7. The test method for an external DC bias device for a network analyzer according to claim 6, characterized in that, S3 includes: High-frequency test signals from the network analyzer are obtained through the test port connector; The high-frequency test signal is isolated from DC by a DC blocking capacitor and then input into the EUT. The EUT outputs the DC-isolated high-frequency test signal to another DC blocking capacitor. Transmitted to another test port connector via another DC blocking capacitor; The isolated DC high-frequency test signal is output to the test equipment through another test port connector.

8. The test method for an external DC bias device for a network analyzer according to claim 6, characterized in that, The process of acquiring filtering operation data of the π-type filter network, performing filtering operation analysis based on the filtering operation data, and obtaining filtering operation analysis results includes: Input and output data are acquired for the π-type filter network to obtain filter input acquisition data and filter output acquisition data; The filtered input data is compared with a preset abnormal data threshold to obtain the abnormal filtering comparison result. Obtain the abnormal input data of the filter based on the filter anomaly comparison results; Obtain the ratio of the filtered input abnormal data to the preset filtered abnormal data threshold to obtain the filtered input abnormal coefficient; Obtain the filter output anomaly coefficient from the collected filter output data; Calculate the difference between the abnormal coefficients of the filter input and the abnormal coefficients of the filter output to obtain the filter difference data; The filtering process is determined based on the filtering difference data, and the filtering analysis results are obtained.

9. The test method for an external DC bias device for a network analyzer according to claim 6, characterized in that, The process of acquiring the inductor operating data of the RF isolation inductor, performing inductor operating analysis based on the inductor operating data, and obtaining the inductor operating analysis results includes: Input and output data are acquired from the RF isolation inductor to obtain inductor input acquisition data and inductor output acquisition data. The inductor input data is compared with a preset inductor abnormal data threshold to obtain the inductor abnormality comparison result. Obtain inductor input anomaly data based on the inductor anomaly comparison results; The ratio of abnormal inductor input data to a preset abnormal inductor input data threshold is used to obtain the inductor input abnormality coefficient. Acquire the inductor output anomaly coefficient from the inductor output acquisition data; Calculate the difference between the inductor input abnormality coefficient and the inductor output abnormality coefficient to obtain the inductor difference data; The inductor's operation is determined based on the inductance difference data, and the inductor's operation analysis results are obtained.

10. The test method for an external DC bias device for a network analyzer according to claim 6, characterized in that, The process of testing and judging the device's performance based on the filtering and inductance analysis results, and obtaining device test and judgment data, includes: When both the filter operation analysis result and the inductor operation analysis result are deemed as qualified, the device test is deemed qualified. When at least one of the filter operation analysis results and the inductor operation analysis results is deemed as an unqualified operation, the device test is deemed unqualified. When the device test judgment data indicates that the device test is unqualified, the test parameters are adjusted until the device test judgment data indicates that the device test is qualified.

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