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This paper presents a zero-IF Gaussian frequency-shift keying (GFSK) demodulator based on a phase-domain analog-to-digital converter (Ph-ADC) which directly quantizes the phase information of the received complex baseband signal. The Ph-ADC linearly combines the in-phase and quadrature parts of the incoming signal, and the generated phase-shifted versions are fed to comparators to detect the zero-crossings and build a 4-b digital representation of the signal phase. Seeking for a low-area and low-power consumption realization, our proposal employs a resistor-less scheme which performs phase rotations in current domain. Together with the Ph-ADC, the fully integrated GFSK demodulator also includes a channel-filtering programmable gain amplifier and a symbol decision block. Altogether, the demodulator occupies 0.14 mm2 in a 0.13- μm CMOS technology with a total power consumption of 190 μW from a 1-V supply. For a data rate of 1 Mbps and 0.5 modulation depth, the GFSK demodulator requires an EB/N0 of 14.8 dB for a bit error rate of 0.1% considering a flicker noise corner of 150 kHz, obtains a dynamic range of 74 dB, and is able to tolerate carrier frequency offsets of ±170 kHz. This performance safely complies with the requirements of the Bluetooth Low Energy (BLE) standard.

The adsorption and reactions of NO on NiAl(111) at 75 K were studied by high resolution electron energy loss spectroscopy, temperature programmed desorption, Auger electron spectroscopy, and low energy electron diffraction. At low exposure (⩽1 L), NO mainly adsorbs molecularly on top in an upright geometry on Ni atoms. Simultaneously, a small amount of NO dissociates. Higher exposures (⩾2 L up to saturation) lead to the formation of a thin amorphous Al-oxynitride (am-ALON) film. In the presence of am-ALON, a molecular adsorption of NO on am-ALON sites and/or in the neighborhood of ALON islands is observed. Besides the upright geometry, NO molecules are adsorbed in disarranged (bent or tilted) configurations. The growing am-ALON film acts as a catalyst for the reduction of NO to N2O. Substantial amounts of N2O are formed for NO exposures higher than 5 L, and are coadsorbed molecularly. The main thermal desorption products are N2O, N2, and NO. For an exposure of 20 L NO, the ratios of the amounts of desorbi...

The oxidation of NiAl(111) was investigated in the temperature region between 300 and 1500 K by HREELS (high resolution electron energy loss spectroscopy), AES (Auger electron spectroscopy) and LEED (low energy electron diffraction). The adsorption of oxygen up to saturation at room temperature leads to the formation of a thin amorphous Al-oxide film. After annealing the oxygen-covered sample to temperatures between 900 and 1100 K a well-ordered Al-oxide with hexagonal symmetry is found. The HREEL spectrum exhibits losses at 53, 79 and 110 meV. This suggests the formation of thin ordered γ′-Al2O3 films on the surface. After annealing the sample above 1100 K the HREEL spectrum exhibits only two losses at 78 and 113 meV which are attributed to thin α-like Al2O3 layers. These Al-oxide overlayers contain less oxygen and the surface is facetted. The surface consists in (111) terraces and (110) facets which form triangular pyramids.

The high-Tc superconductor YBa2Cu3O7 − x(100) surface was studied by high-resolution electron energy loss spectroscopy (HREELS), Auger electron spectroscopy (AES) and low-energy electron diffraction (LEED). Both thin films and cleaved single crystals were investigated. The surfaces of the epitaxially grown thin films were contaminated with carbon which could be removed by sputtering with Ar+ ions. HREEL spectra of these sputtered surfaces exhibit losses at 440 and 630 cm−1. A high background was also found in the HREEL spectra. The background diminishes with decreasing temperature, which is typical of non-conducting materials. The surfaces of the cleaved single crystals were contamination-free. The LEED pattern corresponds to a (1 × 1) structure. In the HREEL spectra losses at 365, 453 and 630 cm−1 were found. These losses could also be observed far above Tc and are due to different vibrations of the oxygen atoms. The appearance of the mode at around 630 cm−1 for both the thin films and cleaved single crystals shows that in both cases non-superconducting layers exist on the surface.

For the revised edition of German Cooling Loads (VDI 2078), some investigations were made with results which could be interesting also for other countries, for example, concerning the finer structure of climatic zones and the atmospheric turbidity. Cooling load calculation needs information on radiation through different types of glass. For the angle-dependent transmission, one could not find till now sufficiently exact measuring results. Therefore, research work was started in Germany to give precise information for special reflection glasses. First results are presented in this paper.