Electronic measurement systems in the THz frequency range are often bulky and expensive devices. While some compact single-chip systems operating in the high millimeter-wave frequency range have recently been published, compact measurement systems in the low THz frequency range are still rare. The emergence of new silicon-germanium (SiGe) semiconductor technologies allow the integration of system components, like oscillators, frequency multipliers, frequency dividers, and antennas, operating in the low THz frequency range, into a compact monolithic microwave integrated circuits (MMIC), which contains most components to implement a low-cost and compact frequency-modulated continuous-wave-radar transceiver. This article presents a single transceiver solution containing all necessary components. It introduces a $0.48\,\mathrm{THz}$ radar transceiver MMIC with a tuning range of $43\,\mathrm{GHz}$ and an output power of up to $-9.4\,\mathrm{dBm}$ in the SG13G3 $130\,\mathrm{nm}$ SiGe technology by IHP. The MMIC is complemented by a dielectric lens antenna design consisting of polytetrafluoroethylene, providing up to $39.3\,\mathrm d\mathrm B\mathrm i$ of directivity and half-power beam widths of 0.95∘ in transmit and receive direction. The suppression of clutter from unwanted targets deviating from antenna boresight more than 6∘ is higher than $24.6\,\mathrm d \mathrm B$ in E- and H-Plane.

The aim of this study was to evaluate a case-mix system to classify inpatients with mental disorders in Germany by means of self-report and expert-rated instruments. The use of case-mix systems enhances the transparency of performance and cost structure and can thus improve the quality of mental health care. We analysed a consecutive sample of 1677 inpatients with mental disorders from 11 hospitals using regression tree analysis. The model assigns patients to 17 groups, accounting for 17% of the variance for duration of stay. Patients with eating disorders had a longer duration of stay than patients with anxiety disorder, duration of mental illness of less than 3–5 years, lower levels of interpersonal problems and higher occupational position. The results showed that besides diagnosis, variables such as duration of illness and interpersonal problems are important for classifying inpatients with mental disorders. The results of the study should be critically reviewed regarding the empirical results of other studies and the appropriateness of case group concepts for inpatients with mental disorders.

Operation of single crystalline Ca3TaGa3Si2O14 (CTGS) and La3Ga5SiO14 (LGS) bulk acoustic wave resonators is demonstrated up to 1270 °C and 1470 °C, respectively. The mass sensitivity of such devices is about 35 cm2 Hz/μg at 800 °C. Therefore, they are sensitive transducers suited to monitoring, for example, mass deposition processes at high temperatures. The electromechanical loss in CTGS is found to be significantly lower than that in LGS. Platinum coated CTGS samples show a remarkable long-term stability at 1000 °C in air. After an initial period of 300 h, the conductivity is found to remain nearly constant for at least 2400 h. Measurements of resonance frequency of CTGS for 1000 h show a qualitatively similar sequence, with an initial systematic increase followed by nearly constant values. In contrast, measurements on platinum-coated LGS plates show a conductivity decreasing by 15 % over a period of 5000 h.

CTGS (Ca3TaGa3Si2O14) is a commercially available, Czochralski-grown piezoelectric material from the langasite family that has an ordered crystal structure. It can be excited piezoelectrically up to at least 1285 °C, which is very close to the melting temperature of 1350 °C. In order to determine the loss at elevated temperatures, two different resonance techniques are used. A contactless transduction method is employed up to about 600 °C, whereas transduction involving standard keyhole-shaped film electrodes is employed up to 1285 °C. Comparison of the temperature-dependent inverse Q factor shows that contactless measurements are best suited for the lower temperature range, where sample clamping and losses caused by the electrodes contribute significantly to the total loss. However, at higher temperatures, measurement of the electrical impedance of samples with film electrodes in the vicinity of the resonance frequency proves to be suitable. Even at 1100 °C, 5 MHz CTGS resonators are found to have a Q factor of about 1200, which is great enough to enable numerous bulk-acoustic-wave applications. Further, a nearly linear temperature dependence of the resonance frequency with a temperature coefficient of 210 Hz/K makes Y-cut CTGS well suited for temperature-sensing applications.

The electrical and electromechanical properties of lithium niobate single crystals are investigated at high-temperatures. The total electrical conductivity is determined as a function of temperature by impedance spectroscopy for Z-cut crystals with different lithium content. For stoichiometric lithium niobate (sLN) the activation energy is found to be (1.49 ± 0.03) eV in the temperature range from 500 to 900 °C.

Further, the piezoelectric properties (resonance frequency, Q-factor) of X-cut lithium niobate crystals are determined at high temperatures for samples with compositions ranging from congruent to stoichiometric and, subsequently, compared to the conductivity data in order to identify loss contributions.

In this context, the high-temperature stability is examined for X- and Z-cut samples with compositions ranging from congruent to stoichiometric. Series of samples with and without additional alumina protection layers are annealed in air at 900 °C for approximately 50 h. Subsequently, depth profiles are measured by SNMS. In all cases, no lithium loss is observed and, therefore, a high-temperature stability of sLN for at least 50 h at 900 °C can be assumed in ambient air.

Further, the influence of protective layers with different thicknesses and compositions is investigated for X- and Z-cut samples. A lithium loss in the first 300 nm is observed for the Z-cut samples, while the X-cut samples show a behavior dependent on the type of protecting layer.

The availability of high-temperature stable surface acoustic wave (SAW) devices would enable realization of wireless sensors for monitoring high-temperature processes. One of the most promising substrate materials for SAW based high-temperature sensors is langasite (LGS, La3Ga5SiO14). It can be excited piezoelectrically up to its melting point at 1470 °C. However, gallium evaporation and degradation of the electrodes limit the application of LGS in SAW sensors for harsh environments to some extent.

The objectives of this work include the investigation of the gallium loss in the vicinity of the langasite surface in oxidizing, reducing and vacuum conditions at temperatures up to 900 °C. The gallium content in the vicinity of the LGS surface is not decreased after annealing the samples in air, while a significant gallium loss occurs in vacuum and reducing atmospheres (0.5 % H2/Ar). The latter results in a gallium oxide deficient region of 1.5 μm below the surface after annealing for 12 hours at 900 °C. The gallium loss is virtually completely suppressed after protecting the surface with a thin alumina film.

Further, thin-film electrodes based on platinum and platinum/rhodium are tested. While conventional platinum based electrodes are completely destroyed at 900 °C within hours due to agglomeration, alumina protected electrodes can be operated at least for several days at this temperature. After 400 hours at 700 °C, the alumina protected platinum electrodes show insignificant degradation. The influence of alumina passivation layers on the stability of the SAW devices is examined. Different electrode configurations are tested with respect to their long-term frequency stability at 650 °C.

The formation and evolution of hydrogen- and vacancy-related donor and acceptor states were studied in helium-implanted and subsequently hydrogen plasma-treated n-type Float-Zone (FZ) silicon wafers by means of two-point-probe Spreading Resistance (SR) measurements. He+-implantation was executed at 3.75 MeV and 11 MeV at fluences of 1×1014 cm−2. Post-implantation 13.56-MHz RF-plasma hydrogenations were carried out at 150 W either for 15 min or 1 hour, applying substrate temperatures between 350 °C and 500 °C. Enhanced donor concentrations as well as acceptor-like states were observed in the subsurface layers of the treated FZ Si samples after 15-min post-implantation H-plasma exposures. Under appropriate process conditions, the latter ones compensated for the n-type doping, so that even buried p-type layers were created. The experimental results indicated that oxygen played a central role in the formation of the acceptor-like states.

By means of two-point-probe Spreading Resistance (SR) analyses, the formation and evolution of hydrogen-related and vacancy-related donor and acceptor states were studied in helium implanted and subsequently hydrogen plasma-treated n-type Float-Zone (FZ) silicon wafers. He-implantation was carried out at 3.75 MeV, applying fluences of 1×1014 cm-2 and 2×1013 cm-2. After 15-min post-implantation H-plasma exposures at substrate temperatures between 350 °C and 500 °C, distinct surplus doping profiles were observed in the subsurface layers of the treated FZ Si samples down to about 20 μm depth. Enhanced donor concentrations could be observed as well acceptor-like states, at least partially compensating for the initial n-type doping, so that even buried p-type layers can be created under appropriate process conditions. The nature of the defect complexes that were responsible for the observed doping profiles in the subsurface layer of the studied samples will be discussed.

Objective: Recent years have shown an increase in the use of questionnaires measuring health-related quality of life to verify the quality of treatment in the field of oncology. An often used cancer-specific questionnaire is the “Quality of Life Core Questionnaire of the European Organization for the Research and Treatment of Cancer” (EORTC QLQ-C30). The purpose of this study is to analyze the psychometric properties of the EORTC QLQ-C30 (version 1) in order to determine the feasibility and appropriateness for its use in inpatient cancer rehabilitation in Germany with heterogeneous diagnoses.

Methods: The questionnaire was administrated to a sample of 972 cancer patients at the beginning of treatment and to 892 patients after treatment. Besides descriptive analysis, the statistical analyses include confirmatory analysis and the multitrait/multimethod approach to test the questionnaire's postulated scale structure (factorial validity) and its reliability (internal consistencies). The analysis also includes a comparison of responsiveness indices (effect size, reliable change index) to test the sensitivity of the instrument.

Results: The EORTC QLQ-C30 showed satisfactory levels of reliability and sensitivity, but the postulated scale structure could not be confirmed. The results illustrate that the varimax-rotated solution of a principal component analysis does not confirm the scale structure postulated by the authors. Correspondingly, the selected fit indices within the scope of the confirmatory factor analysis do not show satisfactory results either.

Significance of results: We therefore consider version 1 of the EORTC QLQ-C30 to be only limitedly useful for the routine assessment of changes in the quality of life of cancer patients in inpatient rehabilitation in Germany, especially because of the instrument's length and possible redundancies. For this reason, a scoring procedure limited to a subset of items is suggested, revealing satisfactory to good psychometric indices. However, further psychometric tests are necessary, especially with regard to validity and sensitivity.

Very often, the performance of modern electron microscopes is limited by the poor quality of the laboratory rather than by the specifications of the microscope. Therefore, with microscopes aiming at subangstrom resolution microscopy and highest performing holography methods, special measures have to be taken to reach the needed low level of AC-stray fields, vibrations, and acoustic noise. in an ”organically“ grown institute, this is very difficult to realize, if possible at all.

• The Triebenberg Lab is newly built well outside the city of Dresden, in an area essentially free from disturbances, i.e. free from power lines, away from roads, trains and airplanes; fortunately, the site is shielded from wind by means of a dense belt of trees. The lab houses six microscope units each consisting of a microscope room, a room for peripheral devices (power supply, cooling units, computers, etc), and an office for up to three scientists. in view of the nearly ideal environment, the main challenge is to avoid any self-made disturbances which might arise by the operation of the lab. Therefore, without any compromise using the best art of engineering, we designed a special lab virtually free from disturbances. in the following, the main guidelines for the construction are sketched.