In this contribution we design and analyze pulse shaping filters for use in IEEE 802.15.4a transmitters. They are developed and evaluated for channels 1-4 in the low band. We analyze the minimum requirements for IEEE 802.15.4a standard compliance and design passive filters which shape a given input pulse stream at baseband. Further, we simulate these filters by using S-parameter models of available components and optimize the resulting designs for standard compliance of the baseband transmit pulse with an iterative method. Finally, we compare the simulations with measurement results and evaluate our design by means of an IEEE 802.15.4a transmitter application.

A fast-growing percentage of vehicles are connected by mobile data service technologies. Up to now most of these connections are based on cellular phone standards. The drawbacks of this method to connect the vehicles are: The limited availability of the underlying data networks and the amount of parallel point to point connections needed to cover all users with extensively similar data. A novel approach to overcome these issues is using a ubiquitously available broadcast medium for general downlink data. For this medium the Ku-Band satellite link has been chosen, as it is well developed, ubiquitously available and cheap compared to other satellite broadcast services. The general advantage of broadcasts is that spectrum has to be bought only once, even for thousands of receiving vehicles. Up to now the receiving antenna for the vehicle hindered integration in commercial cars. The problem resulted from a lack of gain, reliability or from inappropriately large manufacturing expenses. This document proposes an array that overcomes these issues and lists the simulation results for a rectangular array of thirty-six elements.

Conventional RFID (radio frequency identification) systems operating at one single carrier frequency can hardly handle the great variety of shapes and materials that occur in products and packaging. In this contribution a dual-band antenna is presented that allows operation in the 13.56 MHz band as well as in the 868 MHz band. This provides two options to establish a data link to each object equipped with a dual-band RFID tag. The credit-card sized antenna consists of a very thin copper- plated polyimide substrate that is flexible and can be integrated into packaging. Measurements revealed that the antenna provides a quality factor of 54 in the 13.56 MHz band and a gain of -4.69 dBi in the 868 MHz band.

In order to cope with the environmental impacts on Bluetooth data transmission, diversity techniques were examined. A Bluetooth antenna diversity demonstrator was developed. Extensive experimental investigations documenting the significant improvements of data communication employing diversity have been done. It was shown that the effects of multipath and fading could be combated to a large extent by antenna diversity. Thus, antenna diversity was found to be a powerful technique for improving the quality of Bluetooth links.

The next generation of cordless telephones in Europe will conform to the DECT (Digital European Cordless Telecommunications) standard. This standard makes a change from today's analog FDMA (Frequency Domain Multiple Access) transmission to the fully digital FDM/TDD/TDMA (Frequency Domain Multiplex/Time Domain Duplex/Time Domain Multiple Access) system. Also, channels will be assigned dynamically at request of the mobile. For the performance of this transmission and access method under indoor conditions no experimental results have been published. Only a few computer simulations of system behavior have been carried out. The authors have set up a testbed for (i) verification of the DECT standard's physical- and medium access-layer specifications, (ii) testing of DECT equipment under typical indoor conditions, and (iii) finding the limitations of a DECT link for indoor and outdoor applications especially in a slightly dispersive radio channel. They present the principle of the DECT testbed, its practical realisation and a few illustrative measurement examples.>

We have transferred the principle of the Costas-type nonlinear phase-locked loop to the\lambda = 10.6 \mum wavelength of CO2lasers. The ability of the optical Costas loop to regenerate the carrier of a binary phase-shift-keyed input signal and to perform coherent demodulation was demonstrated at a data rate of 20 Mbits/s.