Sonali Luniya

Design and CAD for 3D integrated circuits

High density through silicon vias (TSV) can be used to build 3DICs that enable unique applications in computing, signal processing and memory intensive systems. This paper presents several case studies that are uniquely enhanced through 3D implementation, including a 3D CAM, an FFT processor, and a SAR processor. The CAD flow used to implement for these designs is described. 3DIC requires higher fidelity thermal modeling than 2DIC design. The rationale for this requirement is established and a possible solution is presented.

Design for 3D Integration and Applications

3D stacking and integration can provide system advantages equivalent to up to two technology nodes of scaling. This paper explores application drivers and computer aided design (CAD) for 3D ICs.

High dynamic range transient simulation of microwave circuits

Advances in communication hardware urges a need for simulation tools, which can deal with large mixed signal circuits. For the first time, a transient circuit analysis using state variables, with high dynamic range is presented. The dynamic range of the analysis is experimentally verified by a two tone time domain simulation on a X-band MMIC.

Compact Electrothermal Modeling of an X-band MMIC

Compact electrothermal modeling of lumped electrical devices and compact thermal modeling of volumetric materials enables efficient electrothermal modeling of microwave circuits. The compact thermal model of the body of an X-band MMIC is based on analytical solutions of the heat diffusion equation in thermal sub-volumes. The model is accurate and captures thermal nonlinearities. The model considers complex MMIC features such as surface metallization and vias, as well as the mounting configurations including lead-frame, carrier, and printed circuit board. This is coupled with electrothermal models of transistors and of resistors. The models are incorporated in a multi-physics simulator that uses the same model in both transient and harmonic analysis of an X-band LNA MMIC. Simulations are validated with steady-state thermal measurements

Streamlined Circuit Device Model Development with fREEDAR® ãnd ADOL-C

1 Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, NC 27695-7914. E-mail addresses for the NC State authors are, in order: fphart@eos.ncsu.edu, nmkripla@unity.ncsu.edu, srluniya@unity.ncsu.edu, and m.b.steer@ieee.org. 2 Department of Electrical Engineering, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7B 5E1, Canada. E-mail address: c.christoffersen@ieee.org.

Modeling nonlinear distortion of ultra wideband signals at X-band

Nonlinear distortion in the adjacent channels of an X-band amplifier driven by an ultra-wideband digitally-modulated carrier is analyzed. Statistical properties of the input signal with a complex power series-based behavioral model of the amplifier are used to calculate the output power spectrum. Comparisons are made between measured and predicted adjacent channel power rejection for the X-band monolithic microwave integrated circuit.

Thermal analysis and verification of a mounted monolithic integrated circuit

As circuit density increases and high-power applications are facilitated, thermal considerations become paramount a design concern. In this paper, a high power monolithic microwave integrated circuit (MMIC) is modeled by the fREEDA multi-physics simulator and measured for validation. While validation is the crux of any simulation model, it is known that thermal measurements accurate to a high resolution are problematic. As such, the thermal profile of integrated circuits cannot be measured directly with infrared thermal imaging due to unequivalent emissivities of materials. It becomes necessary to use an absorptive ink to approximate a blackbody so that the infrared emissions can be used to infer temperature. The impact and effect of this thermal imaging technique is investigated in this work by comparing measurements with detailed thermal simulations with and without the surface treatment. Thermal analysis uses the finite element method and a reduced-order model based on cuboids with effective thermal conductivities. The end goal is to provide a simulation tool to designers, which can be extended to any project which requires attention to thermal preference.

fREEDA: An Open Source Circuit Simulator

fREEDAtrade is capable of transient, wavelet, harmonic balance, DC and AC analysis of circuits. Of these it is transient analysis has the greatest capability of revolutionizing the ability to design of RF circuits. fREEDAtrade uses a number of new strategies to achieve a dynamic range in transient simulation exceeding 160 dB, large signal noise analysis, modeling of oscillator phase noise, handling arbitrarily long time delays, and capturing mixed-physics. For the first time the overall philosophy behind fREEDAtrade is outlined with particular attention to topology