Winfried Simon

Comparisons of computed mobile phone induced SAR in the SAM phantom to that in anatomically correct models of the human head

The specific absorption rates (SAR) determined computationally in the specific anthropomorphic mannequin (SAM) and anatomically correct models of the human head when exposed to a mobile phone model are compared as part of a study organized by IEEE Standards Coordinating Committee 34, Sub-Committee 2, and Working Group 2, and carried out by an international task force comprising 14 government, academic, and industrial research institutions. The detailed study protocol defined the computational head and mobile phone models. The participants used different finite-difference time-domain software and independently positioned the mobile phone and head models in accordance with the protocol. The results show that when the pinna SAR is calculated separately from the head SAR, SAM produced a higher SAR in the head than the anatomically correct head models. Also the larger (adult) head produced a statistically significant higher peak SAR for both the 1- and 10-g averages than did the smaller (child) head for all conditions of frequency and position.

A 30 GHz highly integrated LTCC antenna element for digital beam forming arrays

The increasing demand for mobile access to fast data services is one of the drivers for future broadband satellite systems. In-flight data exchange between aircraft and satellites for real-time Internet access is a prominent example for this kind of satellite link. Antennas employing digital beam-forming provide the fast and flexible reconfigurability required in such a system without the necessity for moving mechanical parts. The antenna presented is a circularly polarised, 4/spl times/4 element array building block. This module can be used for a digital beam forming terminal transmitting system operating at 29.75 GHz (Baggen, L. et al., IEEE Phased Array Systems and Technology, p.571-76, 2003). The array features a calibration network as well as transmitting circuitry for each single element. This high density integration task is achieved by the vertical integration of antenna and circuitries in an LTCC multilayer module.

Small and light 24 GHz multi-channel radar

Within the past years radar technology has become more and more important for the civil market. There are many applications where radar is an interesting solution. The main advantage of radar is robustness against weather and light conditions. Distance is measured directly and by adding multi-channel capabilities it is possible to detect the angle of a target. The here presented radar module is a very compact and light weight module which is able to obtain a real-time 2D scan of the vicinity and can easily be integrated in a UAV system.

Designing complex frontend modules for Ka-band and WiGig communication using XPU-technology

Highly integrated RF-frontends are a key component for K/Ka-band satellite communications on-the-move, multimedia entertainment systems, 5G mobile communication as well as 60 GHz broadband home access equipment and backbone networks. Designing such complex modules poses real challenges. These RF-frontends are not only composed of a large number of antenna elements but also of highly integrated complex multilayer feeding structures, RF-transitions, RF-components and power combiners. This paper presents how the XPU technology, which is a smart implementation of the Finite Difference Time Domain (FDTD) algorithm on modern CPU architectures, enables a time-efficient design of frontend modules for Ka-band and WiGig communication, speeding up the whole development process.

EMPIRE XCcel: Efficient simulation of RF MEMS and antennas with XPU FDTD technology

This paper presents how EMPIRE XCcel uses its XPU technology to efficiently simulate RF Mems switches and large antennas including environment. The XPU calculation technique (software accelerated computing on modern CPUs) speeds up FDTD simulations using modern consumer PC and workstations [2]. This XPU technique outperforms the simulation size and simulation speed for FDTD EM simulations on GPU cards.

Efficient and accurate EM simulation of large array antennas and imaging systems

Computational techniques have reached a level of maturity which enables their use for large and complex applications. This paper introduces a new XPU calculation technique (software accelerated computing on modern CPUs) which speeds up Finite Difference Time Domain (FDTD) simulations on modern consumer PCs and server workstations. This allows the usage of the 3D full wave FDTD method for accurate simulations of large array antennas and imaging systems. It is shown that the XPU simulation technique outperforms comparable state-of-the-art GPU-solutions by a factor of about 2.5 in simulation speed and by a factor of >; 8 in maximum simulation size.

Effect of the variation in population on the whole body average SAR of persons exposed to vehicle mounted antennas

Vehicle mounted antennas are widely used for mobile communication in multiple frequency bands. This paper investigates the effect of the variation in population on the Whole Body (WB) averaged SAR at frequencies between 30 MHz and 1 GHz in specific practical exposure conditions.

Efficient FDTD Parallel Processing on Modern PC CPUs

In the first part this paper describes special algorithms for FDTD based field solvers which increase the simulation speed. Based on a new equivalent circuit for the FDTD calculation scheme a new stability criteria is derived which speeds up the simulations for thin sheets. The new processor generations like Pentium Ill/Pentium IV and Athlon/Athlon XP have extensions that allow multiple floating point operations within one processor cycle. These extensions can be used to speed up Finite Difference Time Domain simulations. To exploit these extensions efficiently it is necessary to create a processor and structure dependent assembler code for each simulation automatically. The second part of the paper applies the enhancements invented for the FDTD technique to simulations of a UWB vivaldi antenna. The vivaldi antenna was optimized to achieve a good match and a stable gain over a broadband frequency range. The return loss of this UWB antenna is better than 10 dB for the frequency range from 3 GHz up to 16 GHz. Based on the frequency dependent farfield characteristics the spatio-temporal transfer function of the antenna was calculated. This allows the determination of all relevant quality measures of UWB antennas such as effective gain or ringing.

Efficient analysis of complex antenna arrays using Empire XCcel TM

This paper demonstrates the performance of the Empire XCcelTM field solver, which has been used as the design tool for a highly integrated LTCC antenna element for digital beam forming at 30 GHz. The modelling aspects as well as the simulation details will be emphasized.