Novel Equivalent Circuit Model for Spiral Inductors on Lossy Silicon Substrate

2013 ◽  
Vol 300-301 ◽  
pp. 1003-1007
Author(s):  
Juan Zou ◽  
Zhe Nan Tang

Abstract. A fast and accurate equivalent circuit model for spiral inductors on lossy silicon substrate is presented and the parameters of the model are extracted without applying any fitting and optimized methods. In this model, the lateral resistance and inductance of substrate are introduced to model the eddy-current losses induced by magnetic coupling between the spiral and the substrate. FastHenry method is used to extract the inductances of spiral, substrate, and the mutual inductance between them. A numerical formulation is used to efficiently capture the proximity and skin effects in metal tracks. The proposed model is used to predict the performance of two typical spiral inductors fabricated in CMOS technology. The model shows excellent accuracy and efficiency by the comparison with measure results at the frequency from 100MHz to 10GHz.

2021 ◽  
pp. 136943322110509
Author(s):  
Zhiguo Shi ◽  
Cheng Ning Loong ◽  
Jiazeng Shan

This study proposes an equivalent circuit model to simulate the mechanical behavior and frequency-dependent characteristic of eddy current (EC) damping, with the validations from multi-physics finite element (FE) modeling and dynamic testing. The equivalent circuit model is first presented with a theoretical expression of the EC damping force. Then, the transient analysis with an ANSYS-based FE model of an EC damper is performed. The time-history forces from the FE model are compared with that from the proposed equivalent circuit model. The favorable agreement indicates that the proposed model can simulate the nonlinear behavior of EC damping under different excitation scenarios. A noncontact and friction-free planar EC damper is designed, and its dynamic behavior is measured by employing shake table testing. The experimental observations can be reproduced by the proposed equivalent circuit model with reasonable accuracy and reliability. The proposed equivalent circuit model is compared with the classical viscous model and the higher-order fractional model using a complex EC damper simulated in ANSYS to show the advantages of the proposed model regarding model simplicity and prediction accuracy. A single-degree-of-freedom (SDOF) structure with different EC damping models is further analyzed to illustrate the need for accurate EC damping modeling.


2018 ◽  
Vol 32 (08) ◽  
pp. 1750358
Author(s):  
Wei Wang ◽  
Ting Chen ◽  
Linshu Yan ◽  
Xiaoyuan Bao ◽  
Yuanyuan Xu ◽  
...  

The equivalent circuit model of Ge/Si Separate Absorption Charge Multiplication Avalanche Photodiode (SACM-APD) is proposed. Starting from the carrier rate equations in different regions of device and considering the influences of non-uniform electric field, noise, parasitic effect and some other factors, the equivalent circuit model of SACM-APD device is established, in which the steady-state and transient current voltage characteristics can be described exactly. In addition, the proposed Ge/Si SACM APD equivalent circuit model is embedded in PSpice simulator. The important characteristics of Ge/Si SACM APD such as dark current, frequency response, shot noise are simulated, the simulation results show that the simulation with the proposed model are in good agreement with the experimental results.


2021 ◽  
Vol 10 (4) ◽  
pp. 1936-1943
Author(s):  
Joni Welman Simatupang ◽  
Wilbert Wijaya ◽  
David Tyler ◽  
Clementine Mavridis

For more than 50 years, transcutaneous electrical stimulation method has been used to cure the spinal cord injury, stroke or cerebral palsy. This method works by activating the excitable nerves, muscle fibers by electrical current stimulation through electrode to skin interface. Electrode to skin interface requires equivalent circuit to overcome the inability of measuring the skin resistivity directly. We have learned several previous models, which are from Lawler, Moineau and Keller and Kuhn. Unfortunately, Moineau model neglects the capacitance effect, while Lawler and Keller and Kuhn include capacitive and resistive nature of skin in their equivalent circuits. Both models consisted of only one parallel RC block. Therefore, this paper presents the simulation results of the proposed equivalent circuit model using two parallel RC circuits. Simulation of the proposed model is conducted in MATLAB 2015a and compared with two previous models using certain parameters. Results show that the proposed model obtained the impedance of 10.830 kΩ when it is simulated using 100Hz frequency, for Lawler model the impedance is 5.340 kΩ and Keller and Kuhn model the impedance obtained is 6.490 kΩ. The proposed model has the refined impedance compared with other models and is expected to deliver better electrical stimulation.


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