Equivalent circuit structure and parameter measurement method and apparatus of passive device

Abstract

The invention provides an equivalent circuit structure and parameter measurement method and apparatus of a passive device. A wideband signal with an adjustable parameter is sent to obtain a complete frequency response of a to-be-measured passive device; and a high-order channel characteristic expression (ARMA zero-pole model) is used for approaching the frequency response. Factorization or residue decomposition is carried out to decompose the high-order channel characteristic expression into a plurality of one-order and two-order minor product or sum forms and each minor corresponds to one low-order RLC circuit. And then the to-be-measured passive device is equivalent to a series / parallel model of a plurality of one-order and two-order RLC circuits and impedance values of all resistor, inductor and capacitor elements are obtained. Besides, the apparatus comprises a human-machine interaction module, a data processing unit, a D / A converter, an A / D converter, a test circuit, a clamp fixture, and a power supply. According to the apparatus, the circuit structure is simple; and a high-order equivalent circuit of a to-be-measured passive device can be provided with high precision.

Description

technical field [0001] The invention relates to the technical field of impedance measurement, in particular to an equivalent circuit structure of a passive device and a parameter measurement method and device, which can be equivalent to a series / parallel structure of multiple first-order and second-order RLC circuits of the passive device to be tested , and give the impedance values ​​of the individual resistive, inductive, and capacitive elements. Background technique [0002] In the manufacture of high-quality products and the construction of a high-efficiency production environment, the importance of measurement technology is increasing day by day. Accurate measurement of the impedance of key components is of great significance for judging whether the product is in good working condition. In the field of measurement, if the equivalent circuit structure of passive devices can be obtained through measurement, it will play an important role in promoting device matching circu...

AI Technical Summary

Problems solved by technology

Manual adjustment using the bridge method can achieve high-precision measurement, but because the balance conditions of complex impedance are more complicated, the higher the precision, the more complicated the circuit structure, and the more cumbersome the adjustment operation; Automatic measurement requires both the advantages of precision and automatic measurement, resulting in complex measurement circuits and high costs

[0007] For example, for a portable impedance measuring instrument based on FPGA (patent No. CN102175921A), the key to its measurement is the self-balancing bridge circuit, and the price of its low cost and portability is that the measurement accuracy is reduced

[0008] 3. The resonance method requires a higher frequency excitation signal, which is generally not easy to meet the high precision requirements. Since the test frequency is not fixed, the test speed is also difficult to increase

[0010] As mentioned above, no matter the instrument for measuring impedance value adopts voltammetry, bridge method or resonance method, it is highly dependent on the hardware circuit. error

Furthermore, the existing instruments and equipment for measuring equivalent circuits of passive devices can only be fitted with internal inherent low-order circuits, which is not only inflexible in fitting methods, but also has low fitting accuracy

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