J. Sathyasree

Bio: J. Sathyasree is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Inductor & Electronic circuit. The author has an hindex of 2, co-authored 3 publications receiving 13 citations.

Compact Modeling of Proximity Effect in High- ${Q}$ Tapered Spiral Inductors

Abstract: This letter presents a technique to accurately predict the proximity effect losses in spiral inductors with variable width and spacing (taper) across the turns. The change in magnetic flux in a spiral turn due to the nearby non-uniformly spaced traces is considered while developing expression that captures proximity effect. A broadband, scalable, and frequency-independent compact model is developed for tapered inductors using the proposed technique. Resistance, inductance, and quality factor ( ${Q}$ ) plots are shown for spiral inductors with different values of taper. Excellent agreement between model and EM simulated/measured data demonstrates the scalability of the proposed model. The proposed model can be used to accurately predict the high ${Q}$ possible with tapered inductors.

A Substrate Model for On-Chip Tapered Spiral Inductors With Forward and Reverse Excitations

Abstract: In this brief, closed-form analytical expressions are obtained to accurately calculate the oxide and substrate (both lateral/vertical) capacitances of the $\pi $ -equivalent circuit model for on-chip tapered spiral inductors. A lateral RC substrate network using the above-mentioned expressions is shown to significantly improve the model accuracy, especially with lower substrate resistivities. Furthermore, improvement in Qmax with reverse excitation in tapered spirals is also accurately predicted by the proposed model. The accuracy of the proposed model is validated till 15 GHz using several inductor geometries across process parameters suitable for the design of RF circuits. Excellent agreement is observed between the model, electromagnetic simulations, and measurements.

Modeling of rectangular on-chip spiral inductors

Abstract: A simple expression for calculating DC inductance of a rectangular spiral inductor is presented Accuracy of the expression is evaluated using field solver simulations We have presented a broad-band frequency independent model

A Substrate Model for On-Chip Tapered Spiral Inductors With Forward and Reverse Excitations

Abstract: In this brief, closed-form analytical expressions are obtained to accurately calculate the oxide and substrate (both lateral/vertical) capacitances of the $\pi $ -equivalent circuit model for on-chip tapered spiral inductors. A lateral RC substrate network using the above-mentioned expressions is shown to significantly improve the model accuracy, especially with lower substrate resistivities. Furthermore, improvement in Qmax with reverse excitation in tapered spirals is also accurately predicted by the proposed model. The accuracy of the proposed model is validated till 15 GHz using several inductor geometries across process parameters suitable for the design of RF circuits. Excellent agreement is observed between the model, electromagnetic simulations, and measurements.

Compact Fractional-Order Model of On-Chip Inductors With BCB on High Resistivity Silicon

Abstract: Fractional-order calculus exhibits clear advantages over modeling the nonlinear and complex physics phenomena. In this article, fractional-order calculus is introduced to the field of on-chip inductor modeling. A novel fractional-order 1- $\pi $ inductor equivalent circuit model is proposed to characterize on-chip inductors based on silicon-benzocyclobutene (Si-BCB) technology. The proposed model, which contains six integer-order circuit elements and three fractional-order elements, is sufficient to describe frequency-dependent effects, such as the skin effect, proximity effect, and distributed effect. Three fractional-order elements (one fractional-order inductor and two fractional-order capacitors) introduced in the above model are major contributors to improving the model’s accuracy and bandwidth. The parameter extraction method is discussed in this article, and the direct simulation method is employed to solve fractional-order equations. The accuracy of the proposed fractional-order model is validated up to 40 GHz. An excellent agreement is observed between the model and the measurements.

Neural Network Specialists for Inverse Spiral Inductor Design

Abstract: Integrated spiral inductors are a fundamental part of Radio-Frequency (RF) circuits. In certain scenarios, a solution to the inverse spiral inductor design problem is required; given the desired properties of an inductor, locate the most suitable geometric characteristics. This problem does not have a unique solution and current approaches approximate it through a number of differential equations and the subsequent application of optimization techniques that narrow down the set of feasible solutions. In this work, the Neural Network Specialists model is outlined; a preliminary approach to solving the aforementioned problem using fully connected neural network models. The obtained results on a first round of experiments are encouraging, especially in terms of the reduction in time complexity.

Compact Modeling of Series Stacked Tapered Spiral Inductors

Abstract: In this paper for the first time, a frequency independent equivalent circuit model is proposed for series stacked inductors having variable width and space (taper) across their turns. The proposed model accounts for the increase in mutual inductance between the stacked spirals due to taper. Also, the proximity effect losses with tapered top and bottom spirals of the series stack is accurately modeled. Finally, the inter-layer capacitance between the stacked spirals which dictates the self-resonant-frequency of the series inductor is calculated across different values of taper. EM simulations and measurements show excellent correlation with model simulations across different layouts with different values of taper thereby demonstrating the scalability of the proposed model.

Analytical Modeling for the Characterization of On-Chip Spiral Inductor in 0.13 μm

Abstract: In this paper, we present the modeling for a rapid characterization of integrated spiral inductors. Closed-form has been used to estimate the parameters of the equivalent circuit, which are calculated as a function of the parameters of the inductor physical design. The double-$\pi$ equivalent circuit was adopted to model the physical phenomena resulting from electromagnetic coupling and high-frequency operation. The method for calculating the oxide capacitance has included the contribution of the fringing electric fields for better prediction of the inductor characteristics. In order to verify the performed modeling, a set of octagonal on-chip spiral inductors with different geometries were simulated in the Momentum ADS and the main figures of merit of the inductor were compared. The mean error between the model and EM simulation was 3.6% for the DC inductance, 7.7% for the maximum value of the quality factor and 1.3% for the self-resonance frequency.