CST World - Application Articles

3D EM simulation of mixed analog / digital multilayer PCB

Wed, 22 Oct 2008 18:05:58 GMT

This article describes the use of CST CST MICROWAVE STUDIO® (CST MWS) to solve a coupling problem in a mixed analog – digital multilayer PCB card. Courtesy and permission of Alvarion, Ltd, Tel-Aviv, Israel. This example gives an insight into the usefulness of simulation of problems that cannot be investigated easily via measurement and allows the engineer to carry out virtual experiments as demonstrated here with the cutting of the signal trace. Experiments may show the presence of a particular problem but not its location. Even when the problem has been located, further prototypes and experiments are costly and time-consuming. CST MWS offers a straightforward workflow for the set-up and simulation of such problems via its advanced user-interface and EDA interfaces.

Simulation of 650 GHz Backward Wave Oscillators

Wed, 24 Sep 2008 15:34:00 GMT

In this acticle the simulation of novel interdigital backward wave oscillators with CST PARTICLE STUDIO® is described. The mutual coupling of the charged particle movement and transient electromagnetic fields is taken into account by a sophisticated Particle in Cell algorithm. The resulting output power is in excellent agreement with theoretical values. Results are presented with the courtesy and permission of Teraphysics Corporation, USA.

TLM Simulation of Human Exposure to 400MHz Electromagnetic Fields Inside a Car

Mon, 22 Dec 2008 15:02:12 GMT

Transmitters used in vehicle environments present potential threats to the health and safety of vehicle users, in terms of both human exposure to electromagnetic fields and vehicle EMC (electromagnetic compatibility). The recently revised automotive EMC directive (2004/104/EC) now requires vehicle manufacturers to identify acceptable frequencies, powers and antenna installations that can be used on vehicles without compromising their EMC performance. The simulations presented here were performed with CST MICROSTRIPES™.

RFID system design using 3D EM simulation tools

Mon, 06 Oct 2008 16:44:08 GMT

RFID is becoming an increasingly important technology with diverse applications in inventory management and product tracking, identification, timing and the biomedical sector, amongst others. Electromagnetic simulation has become an indispensable design tool for RFID tag design and system analysis. This presentation discusses various topics including full model parameterisation to analyse the effects of construction tolerances and geometric variations in conformal tags, the use of hybrid electromagnetic and circuit simulation for full system analysis, and finally the optimisation of tag geometry and sensor placement to fulfil design goals. This paper was presented by Dr. Marc Rütschlin of CST UK Ltd. at the IDTechEx RFID Europe 2008 conference in Cambridge in October 2008.

Signal integrity analysis and circuit extraction of a mounted SMA connector

Fri, 26 Sep 2008 11:36:38 GMT

A physically based method is used for estimating the equivalent circuit model of an SMA connector soldered on the top plane of a multi-layer board and connected to a single-end stripline. Starting from the scattering parameters (S-parameters) evaluated using a simulation software package, the equivalent circuit is extracted by modeling each part of the structure. The circuit is then validated by comparing the outputs obtained via circuit-level simulation of the extracted physical circuit with those computed by means of the full wave solution.

Full Wave Characterization of a Small Quad Flat Package for High-Speed Serial Interface Application

Tue, 11 Nov 2008 10:38:16 GMT

The target of this study was to understand the impact of low cost digital (=non-RF) packages on high-speed interface drivers and receivers. The studied low cost package was a 64-pin SQFP with dimensions 10x10 mm2, and with body thickness of 1 mm. The 1.4x1.4 mm2 IC with an active area of 0.01 mm2 was mounted on silicon substrate. The bond wires were of gold, with wire diameter 20 µm with bond pad pitch of 70 µm. The considered package contains the physical layer of a serial high-speed chip-to-chip interface circuit, operating with data rates up to 1 Gbit/s.

Assessment of occupational exposure of MRI workers resulting from a time-varying magnetic field associated with a cylindrical z-gradient coil

Tue, 11 Nov 2008 10:37:45 GMT

The exposure of staff in the vicinity of MRI scanners to low frequency (~ 1 kHz) time-varying fields associated with gradient coils is currently of interest in view of limits prescribed in the European Union Directive 2004/40/EC (1) due to be legally enforced from April 2008. Concern has been raised regarding the likely impact that exposure limits described in (1) will have on MRI practice but currently there is little information in the literature regarding such occupational exposure. In this work we address the interactions of a switched gradient magnetic field with a human body located near to a MRI scanner.