An original, fully analytical, spectral domain decomposition approach is presented for the time-dependent thermal modeling of complex nonlinear (3-D) electronic systems, from metallized power FETs and MMICs, through MCMs, up to circuit board level. This solution method offers a powerful alternative conventional numerical simulation techniques, constructed be compatible with explicitly coupled electrothermal device on CAD timescales. In contrast semianalytical, frequency space, Fourier...

This paper presents a practical implementation of an integrated MRI-compatible CMOS amplifier capable directly driving piezoelectric ultrasound transducer suitable for high-intensity focused (HIFU) therapy. The operates in Class DE mode without the need output matching network. has been implemented with AMS AG H35 process. A class design methodology unmatched loads is presented along simulation and experimental results. proposed achieves approximately 90% efficiency over 800 mW power at 1010...

Reduced-order modeling of distributed structures for transient and steady-state circuit simulation transforms discrete frequency-domain network parameters to a set rational functions. The models are ideally causal passive with passivity being the most difficult property assure, especially when incorporate propagation delay effects or available have limited bandwidth. Small errors in parameters, out-of-band assumptions, can yield that result unstable simulations. Here, an inverse singular...

Two variants of a MOS-only voltage reference are proposed. They based on MOSFETs operating at constant inversion level which cancels out nonlinearities their temperature dependence arising from that mobility. The theory behind the circuits is thoroughly discussed, design method described and experimental results presented. two architectures propose different trimming methods for slope references. A test chip was designed fabricated standard 0.35 μm CMOS technology including both...

Microwave and millimeter-wave systems have generally been developed from a circuit perspective with the effect of electromagnetic (EM) environment modeled using lumped elements or N-port scattering parameters. The recent development local reference node concept coupled steady-state transient analyses state variables allows incorporation unrestrained EM modeling microwave structures in simulator. A strategy implementing global electrically large abstraction is presented. This applied to...

An object-oriented microwave circuit simulation environment is described. The design of the program intended to offer flexibility without sacrificing efficiency. Recent developments in techniques and C++ compilers are used obtain a flexible robust system ideally suited development global modeling strategy for integration circuit, field, thermal, mechanical analyses. spatial power combining systems as vehicle illustrate architectural system. © 2000 John Wiley & Sons, Inc. Int J RF Microwave...

A unique electromagnetic (EM)-electrothermal global simulation tool based on a universal error concept is presented. The advantages of this electrothermal model are illustrated by comparison with commercial circuit simulator. first description fully physical, electrothermal, microwave simulation, coupling the Leeds Physical Model MESFETs and high electron-mobility transistors, to simulator, fREEDA (NCSU), modeling effort supported parallel developments in electrooptic thermal measurement....

For the first time a state variable transient analysis using wavelets is developed and implemented in circuit simulator. The formulation particularly well suited to modeling RF microwave circuits validated by considering nonlinear transmission line. However, results indicate that still more research needed make this method efficient for simulation of large circuits.

This paper presents for the first time an MRI-compatible integrated CMOS amplifier capable of directly driving a piezoelectric ultrasound transducer High Intensity Focused Ultrasound (HIFU) applications. The operates in class DE mode loaded with connected parallel shunt capacitor. There is no need external inductors. implemented Teledyne-DALSA 0.8 μm process. Modeling and design considerations are presented, followed by simulation results obtained using Spectre simulator. proposed achieves...

Large spatially distributed microwave and millimeter-wave systems involve the interaction of linear nonlinear circuits with their electromagnetic environment. Here a circuit-level approach to modeling circuit-field interactions is developed. ©1999 John Wiley & Sons, Inc. Int J RF Microwave CAE 9: 376–384, 1999

Joint computer simulation of circuit, thermal and electromagnetic interactions in high performance integrated circuits systems is particular importance for the modeling electronic packaging, since packages are complex coupled where all these aspects interact a dynamic sense. This paper describes environment that supports simultaneous thermal, circuit microwave circuits. Locally referenced modules have been used to enable disparate tools interact, suggest possible paths include mechanical...

The first fully coupled electromagnetic-electro-thermal global simulation of a large microwave subsystem, here whole spatial power combining MMIC array, is described. modeling effort supported by parallel developments in electro-optic and thermal measurement. CAD tools experimental characterisation described, provide unique capability for the design quasi-optical systems exploration fundamental physics devices.

This paper offers a review of simulation methods currently available for the transient and steady-state analysis nonlinear RF microwave circuits. The most general method continues to be time-marching approach used in Spice, but more recent based on multiple time dimensions are particularly effective We derive nodal formulations widely dimension methods. put special emphasis oscillators warped multitime partial differential equations (WaMPDE) approach. Case studies Colpitts oscillator voltage...

Physics-based compact electrothermal macromodels of standard cells are developed for fast dynamic simulation three-dimensional integrated circuits (3DICs). Such can have high thermal densities and effects often limit their performance. The here use fewer state-variables than a discrete transistor-level implementation while retaining accuracy. This results in significant speed-up over large-scale circuits. macromodel-based methodology enables robust significantly faster the long times...

A state-variable-based approach to the impulse response and convolution analysis of distributed microwave circuits is developed. The state-variable minimizes computation time memory requirements. It allows use parameterized nonlinear device models, thus improving robustness. Soliton generation on a transmission line considered as an example.

A state variable implementation of harmonic balance circuit analysis for spatially distributed systems is developed. The equations are formulated with the minimum number unknowns and error functions starting from modified nodal admittance matrix linear part circuit. program uses advanced numerical techniques, such as automatic differentiation to calculate Jacobian system it compatible port-based network descriptions which occur electromagnetic modeling.

This paper presents an integrated MRI-compatible full-bridge Class-DE ultrasound transducer driver design for HIFU applications. includes a digital logic unit to individually control the phase and duty ratio of each when is used in array configuration. work also shows performance proposed with three different ultrasonic transducers. Simulation results predict at least 89% efficiency two transducers that support ideal operation without matching networks. The has been implemented by using AMS...

This article reports a new method for transient analysis of nonlinear circuits based on device state variables and waves at their ports. The is relaxation thus does not require large matrix decompositions if time step constant. use results in guaranteed convergence any linear passive circuit some types circuits. Additionally, the formulation using ensures that devices are always excited with physically meaningful input, i.e., amount power transmitted to bounded. was implemented fREEDA™...

A harmonic balance (HB) method to analyze the steady-state response of free-running oscillators is proposed. It does not require a good initial guess oscillation frequency and exploits frequency-domain latency circuits by using different number harmonics in each variable. For first time warped multi-time partial differential equation approach used simultaneously bring circuit state region convergence HB analysis determine optimum required at node circuit. The LC-tuned bipolar oscillator...

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

An integrated electromagnetic and circuit simulation environment is developed for the of spatial power combining systems. The analysis incorporates surface modes, nonuniform excitation full nonlinear effects. tools are used to predict performance a 2 by quasi-optical grid amplifier.

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