Electronic circuit simulation

Abstract: There has been a proliferation of technical papers on power device modelling for circuit simulation. Even the power diode, the simplest of all power devices, has been the subject of a fair amount of research interest in the modelling of its characteristics. The issues in the modelling of the power diode for circuit simulation are discussed in this paper, based on the authors' experiences. Among the issues discussed are the modelling techniques, accuracy, validation, implementation, simulation performance and parameter extraction. It is concluded that until the availability of a simple, reliable and well-understood model with standardized parameter estimation procedure, and which is actively supported by commercial simulators, the impact of this modelling work on the computer aided design of power electronics circuits is expected to remain minimal.

Abstract: In this paper, the reversible transducer properties of a piezomagnetic unimorph are investigated experimentally and aggregated in a linear equivalent circuit. The unimorph consists of a single-crystal Galfenol plate, which is mounted to an aluminum plate. Such two-layer piezomagnetic elements are used in bending actuators or sensors. The completed two-port model of the transducer describes the dynamic behavior in sensing, as well as actuation direction, and includes the magnetomechanical interaction. The coupling of the transducer with a solenoid and demagnetization are considered. A circuit simulator can be used to investigate efficiently the dynamic behavior of the system, and circuit theory can be applied to analyze and simplify the equivalent circuit model.

Abstract: A circuit model for vertical transitions between difierent coplanar waveguide systems using via-holes is presented. The model is directly extracted from the geometry of the transition using closed expressions. Additionally, it can be used to flnd suitable initial dimensions for the transition in a circuit simulator, thereby greatly reducing the efiort spent on subsequent electromagnetic simulations. To test the validity of the developed model, it is applied to a variety of situations involving a wide range of stack heights, dielectric constants, and transmission line geometry values. These situations cover most of the relevant broadband vertical transitions used in practical PCB and LTCC designs. Comparative analysis of the circuit model and electromagnetic simulations yields good agreement in all analyzed situations. Experimental assessment of the model is also provided for some of the transitions that were built and characterized in a back-to- back conflguration.

Abstract: Following the release of Qucs-0.0.18 in August 2014 the Qucs Development Team have considered in detail a number of possible directions that future versions of the software could take. Spice4qucs is one of these routes. Spice4qucs is a Qucs extension that allows Qucs schematics, including non-linear Equation-Defined Device compact models, to be simulated with external SPICE-compatible simulation engines. Qucs-0.0.19Src2 uses ngspice and Xyce for this purpose. The recent release of Qucs-0.0.19Src2 includes the latest spice4qucs extensions and is made available as an experimental feature. All Qucs legacy simulation and modelling features remain unchanged. The spice4qucs extensions introduce in release Qucs-0.0.19Src2 include the majority of the SPICE components distributed with the ngspice and Xyce circuit simulation packages. Circuits can be simulated with Qucs qucsator, ngspice and Xyce in particular circuit investigations can be centred around SPICE, .FOUR, .NOISE, and .DISTO analysis, a SPICE compatible parametrization system employing the SPICE .PARAM statement, SPICE behavioural sources, ngnutneg scripts, and an innovative form of Qucs simulation called “Custom Simulation”. The“Custom Simulation” facility allows uses to develop ngnutmeg scripts for circuit design, compact device modelling, Monte-Carlo simulation (and other related circuit statistical routines) and to process simulation output data. Combinations of these new features significantly increases Qucs simulation and modelling capabilities, particularly in established areas like power/RF electronics and new emerging technologies. Qucs-0.0.19Src2 also introduces a preliminary version of a new Qucs EDD to Verilog-A compact model synthesis tool. This feature is released as a GPL open source software tool in support of current compact modelling research.