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This paper presents a frequency domain analysis of spurious tones in frequency dividers. The results of the analysis are used to develop an event-driven model for system simulations which work entirely in the frequency domain. The proposed approach is able to provide a fast and accurate model in a SystemVerilog/C++ environment which takes the frequency conversion effects of the spurious tones into account. A virtual prototype which includes the model was simulated and due to the fast simulation speed it was possible to determine the influence of spurious tones on the bit error rate in a complex receive scenario. [ABSTRACT FROM AUTHOR]

With the development of medical technique and computational electromagnetics, high resolution anatomic human models have already been widely developed and used in computation of electromagnetic fields induced in human body. Although these so called voxel-based human models are powerful tools for research on electromagnetic safety, their unchangeable standing posture makes it impossible to simulate a realistic scenario in which people have a lot of different postures. This paper describes a poser program package which was developed as an improved version of the free-from deformation technique to overcome this problem. It can set rotation angles of different human joints and then deform the original human model to make it have different postures. The original whole-body human model can be deformed smoothly, continuity of internal tissues and organs is maintained and the mass of different tissues and organs can be conserved in a reasonable level. As a typical application of the postured human models, this paper also studies the effect of the step voltage due to a lightning strike on the human body. Two voxel-based human body models with standing and walking posture were developed and integrated into simulation models to compute the current density distribution in the human body shocked by the step voltage. In order to speed up the transient simulation, the reduced c technique was used, leading to a speedup factor of around 20. The error introduced by the reduced c technique is discussed and simulation results are presented in detail. [ABSTRACT FROM AUTHOR]

In this paper two methodologies to reduce the complexity of IC conducted emission models for Power Integrity analysis in ICs are presented. The methodologies differ concerning the applicability in simulation tools, complexity and accuracy of the generated models. The first methodology uses a complex model and reduces its order to generate a model with a fewer number of elements. This methodology therefore involves a model order reduction approach. A second minimum complexity, module based modelling approach is introduced for rough estimations, as the order reduced model is still too complex for some applications. The two methodologies are applied to an IC conducted emission model of two digital modules of a 32 Bit microcontroller. The results of the three models are compared and discussed. Fields of application for the introduced modelling approaches are the estimation of the magnitude and time behaviour of the supply current as well as the determination of the number and position of the IC's supply pins. [ABSTRACT FROM AUTHOR]

By the rising complexity and miniaturisation of the device's dimensions, the density of the conductors increases considerably. Referring to this, locally transient interactions between single physical values become apparent. Therefore, for the investigation and optimisation of integrated circuits it is essential to develop suitable models and simulation surroundings which allow for memory and time-efficient calculation of the behaviour. By means of the dynamic reconstruction theory and the radial basis functions nets the so-called black box models are provided. The description of black box models is derived from the input and output behaviour or so-called time series of a dynamic system. Concerning the time series, the black box model adapts its parameters via the extended Kalman filter. This paper provides a modelling approach that enables fast and efficient simulations. [ABSTRACT FROM AUTHOR]

This paper presents a novel realization concept for Clock-and-Data-Recovery circuits. Our Design uses a nonlinear phase detector architecture, which is based on the Alexander phase detection method. In order to ensure circuit functionality in the RF region, we use very fast switching HLO-Flip-Flops (high-speed latching operation flip-flop) in our design. The primal goal in our design was the minimization of self induced jitter of the phase detector. The accuracy of our circuit design and the functionality in the GHz regime is confirmed by various circuit simulations executed with the SPECTRE Simulator. [ABSTRACT FROM AUTHOR]

In this paper we discuss the expected impact of quantum effects in nanostructured CMOS circuits. In order to describe transport in mesoscopic electronic systems our group develops a 1-d numerical simulation packet based on the "non equilibrium Green's functions" (NEGF) formalism. By means of the obtained simulation results we develop extended SPICE circuit models. With these SPICE models the influence of quantum effects to the functionality of classical circuit concepts can be studied. Using these results it is our intention to develop circuits with a higher robustness against these quantum effects. For the illustration of our simulation concept we discuss some results of some circuit examples. [ABSTRACT FROM AUTHOR]

This paper describes the determination of the screening attenuation with a GTEM cell. An analytical part gives the link between the voltage at the cell port and the total radiated power. The next section investigates the optimal cable setup in the cell. With a measurement of the common mode current on the cable and a simulation of the radiation resistance the loop antenna characteristic of the cable setup could be verified. It is shown that the use of ferrit cores decrease the difference between the maximum and the minimum screening attenuation. The determination of great screening attenuation could be improved with the use of N-type measurement cables. A comparison between this GTEM cell method and the standard methods shows a good agreement. [ABSTRACT FROM AUTHOR]

The exposure of human body to electromagnetic fields has in the recent years become a matter of great interest for scientists working in the area of biology and biomedicine. Due to the difficulty of performing measurements, accurate models of the human body, in the form of a computer data set, are used for computations of the fields inside the body by employing numerical methods such as the method used for our calculations, namely the Finite Integration Technique (FIT). A fact that has to be taken into account when computing electromagnetic fields in the human body is that some tissue classes, i.e. cardiac and skeletal muscles, have higher electrical conductivity and permittivity along fibers rather than across them. This property leads to diagonal conductivity and permittivity tensors only when expressing them in a local coordinate system while in a global coordinate system they become full tensors. The Finite Integration Technique (FIT) in its classical form can handle diagonally anisotropic materials quite effectively but it needed an extension for handling fully anisotropic materials. New electric voltages were placed on the grid and a new averaging method of conductivity and permittivity on the grid was found. In this paper, we present results from electrostatic computations performed with the extended version of FIT for fully anisotropic materials. [ABSTRACT FROM AUTHOR]

In this paper a method for real-time updating of ionospheric electron density profile, N(h), over Europe using an ionospheric model and real-time measurements at ionosonde locations is presented. The N(h) profile update over European area has been simulated with the IRI-2000 ionospheric model and real-time N(h) profiles obtained from the EU COST271 Action Space Weather Database. Preliminary findings are shown for the geomagnetically quiet day on 4 May 2003 and disturbed day on 24 May 2002. Results are discussed in the context of real-time N(h) profile updating capabilities and effectiveness. [ABSTRACT FROM AUTHOR]

Positive Feedback Adiabatic Logic (PFAL) shows the lowest energy dissipation among adiabatic logic families based on cross-coupled transistors, due to the reduction of both adiabatic and non-adiabatic losses. The dissipation primarily depends on the resistance of the charging path, which consists of a single p-channel MOSFET during the recovery phase. In this paper, a new logic family called Improved PFAL (IPFAL) is proposed, where all n- and p-channel devices are swapped so that the charge can be recovered through an n-channel MOSFET. This allows to decrease the resistance of the charging path up to a factor of 2, and it enables a significant reduction of the energy dissipation. Simulations based on a 0.13µm CMOS process confirm the improvements in terms of power consumption over a large frequency range. However, the same simple design rule, which enables in PFAL an additional reduction of the dissipation by optimal transistor sizing, does not apply to IPFAL. Therefore, the influence of several sources of dissipation for a generic IPFAL gate is illustrated and discussed, in order to lower the power consumption and achieve better performance. [ABSTRACT FROM AUTHOR]

This paper shows the potential of MIMO in cellular systems, where small handheld devices are used for the terminals. A complete model of a MIMO communication link is used to integrate accurate antenna modelling into MIMO system simulations. All different effects of mutual coupling between closely spaced antennas are considered. The efficiency or power budget respectively of the antenna arrays in the terminals, which are influenced by mutual coupling effects, is taken into account. Capacity simulation results based on a channel obtained from ray-tracing simulations are shown with cellular phones with up to three Inverted-F antennas. [ABSTRACT FROM AUTHOR]