Abstract: The method ensures the coherent demodulation by digitally processing a continuous-phase modulated signal (for instance, of the GMSK type). The received signal is transposed in the baseband, converted into a digital signal and transferred to a signal processor. Each transmitted data packet has a known preamble sequence of N bits which allows for approximate estimation of the frame-synchronization and the bit-synchronization and also the initial phase and the residual frequency offset. The progressive refinement of the estimation is obtained with two interleaved digital loops: a slow loop for detecting the bit-synchronization and a fast loop effecting intermediate decisions over additional blocks of bits for the estimation of the initial phase and the residual frequency offset.

Abstract: An optical amplifier with a semiconductor body includes a layer structure grown on a substrate, with an active layer between two cladding layers, and a strip-shaped amplification region bounded by two end faces of low reflection which form the input and output faces for the radiation to be amplified. The active layer has a number of quantum well (QW) layers with direct band transition, and separated by barrier layers of a different semiconductor material, a first portion of the QW layers being under tensile stress. Another portion of the layers forming part of the active layer is under compressive stress. Owing to the compressive stress present locally in the amplification region, the TE-mode is more strongly amplified there than the TM-mode, while in the tensile portion of the amplification region the TM-mode is more strongly amplified than the TE-mode. This results in a polarization-insensitive amplifier with higher stress and thus with a large amplification at a relatively low current.

Abstract: A semiconductor body (1 ) is provided having a first region (4) of one conductivity type adjacent one major surface (2). An insulating layer (5) is formed on the one major surface and masking means (6,7) are used to form over first and second areas (20 and 21) of the one major surface (2) windows (8,9,10) in the insulating layer (5) through which impurities are introduced to form a relatively highly doped region (11) of the opposite conductivity type adjacent the first area (20) and a relatively lowly doped region (12) of the opposite conductivity type adjacent the second area (21). The surface (5a) of the insulating layer (5) is exposed prior to introducing impurities of the one conductivity type for forming a region (13) within the relatively lowly doped region (12) of the opposite conductivity type and with a dose sufficient to form the region (13) but not sufficient to overdope the relatively highly doped region (11) so avoiding the need to mask the first area (20) during this step.

Abstract: Device for doubling the frequency of a light wave, comprising a non-linear optical medium of an oriented synthetic resin composition for guiding a fundamental light wave, while forming a second harmonic wave, which medium is composed of a waveguide having a spatially periodic structure for phase matching. The oriented synthetic resin composition exhibits alternate regions having a mutually different second order (non-linear optical) susceptibility. Said structure can be manufactured in an efficient manner by exposing the synthetic resin composition to patterned radiation.

Abstract: A lithographic device with a lithographic irradiation system (1, 13) which is fastened near a lower side to a mounting member (5) of a frame (7). The device is provided with a unit (65) which is formed by a positioning device (37), with which an object table (21) arranged below the irradiation system (1, 13) is displaceable, and by a support member (35), over which the object table (21) is guided by means of an aerostatic foot (31). In an operational position, the unit (65) is coupled to a carrier (67) by means of coupling members (73), the carrier (67) being suspended from the mounting member (5) by means of suspension elements (79, 81, 83), so that the unit (65) is arranged between lower frame supports (25) of the frame (7) and a compact construction is obtained.The unit (65) can be rotated from the operational position to an end position, in which the unit (65) is entirely outside the frame (7) and is easily accessible for maintenance, by means of a rotation mechanism (87) and a swivel mechanism (89).

Abstract: A circuit arrangement (12, 13) for the electronic level control of a sound signal includes an amplifier circuit (14), the gain of which can be controlled in dependence on a variable direct control voltage, and a voltage-adjusting stage (15) for generating the variable direct control voltage. The amplifier circuit is formed by a CMOS inverter (14), of which the supply voltage connection (21), is supplied with the variable direct control voltage, generated by the voltage-adjusting stage (15), as supply voltage for the CMOS inverter (14). The CMOS inverter (14) is operated, in dependence on the direct control voltage, below the knee-point voltage in its starting region in which the gain of the CMOS inverter (14) decreases, and additionally the dynamic output impedance of the CMOS inverter (14) increases, with decreasing direct control voltage.

Abstract: A mirror unit (11) comprising a mirror holder (12) having a cylindrical support surface (13), and comprising a flexible mirror (14) having a mirror side (15) and a rear side (16); the mirror (14) which has been elastically deformed into a cylindrical mirror rests with its mirror side (15) directly on the support surface (13) of the mirror holder (14) without an intermediate layer, the mirror holder being provided with a shaft (17) which leaves open an optically directly and freely accessible region (19) at the mirror side (15) of the mirror (14) (front surface mirror), this region (19) acting as the functional mirror surface.

Abstract: In the manufacture of optical fibers according to the PCVD method, a method is provided wherein the yield of the method (.eta.), in particular at increased deposition rates (m), is raised by reducing the geometrical taper, without forming optical tapers. This is obtained in that glass is deposited in layers on the inside of a glass tube and, simultaneously, on a glass rod having a circular cross-section, which rod is arranged inside the glass tube, such that its longitudinal axis coincides with that of the glass tube, the radius of the glass rod being adjusted to at most 0.67 times and at least 0.2 times the inner radius of the glass tube, and the glass rod being removed from the glass tube upon completion of the deposition process.

Abstract: A circuit arrangement for producing in an inductive load, especially a gradient coil for nuclear magnetic resonance tomography, a current pulse of trapezoidal shape, applies a series of supply voltage pulses, some of positive and some of negative polarity, via an auxiliary inductor to a parallel arrangement of the load and oppositely directed current drains, which are controlled by respective associated control elements. Each applied supply voltage pulse produces a variation of current through the parallel arrangement during the voltage pulse which is more steep than the leading or trailing edge of the current pulse through the load.

Abstract: In a receiver, normal and quadrature components of a signal modulated on a carrier signal (at a second IF frequency) are directly obtained by carrier signal sampling with an analog-to-digital converter (A/D) at sampling instants controlled by periodically recurrent sampling pulses spaced apart by an odd multiple of a quarter period of the carrier signal. In order to create enhanced selection options at selectable carrier frequencies, an odd first number of equidistant sampling instants are combined into a group and a group distance between the last sampling instant of a group and the first sampling instant of the next group is a second integer (different from the second integer) multiple of the quarter period of the carrier. The signal samples at odd and even positioned sampling instants within a group are respectively directed to two different signal branches; the two branches are respectively for determining samples of the normal and quadrature components.

Abstract: A brightness intensifier tube is composed of a cylindrical sleeve portion comprising supporting faces acting as reference surfaces for an entrance window and an exit screen so that a vacuum tight tube with exactly positioned parts can be formed by way of seals provided by application of a single compressive load. Because electrodes of an electron optical imaging system are supported by the windows or the sleeve portion in an exactly positioned fashion, assembly produces exact positioning of the electrode system in the tube.

Abstract: The invention relates to a sintered transformer core of MnZn-ferrite material, the initial permeability of which ranges between 10 and 1000. Said transformer cores preferably have an average particle size which ranges between 0.05 and 2.0 .mu.m. The transformer cores according to the invention exhibit surprisingly low overall losses when operating in the frequency range of 2 MHz and higher. Such transformer cores can be very advantageously used in transformers operated in said frequency range, such as SMPS transformers.

Abstract: A cable winder is provided which comprises a frame plate 1 carrying a shaft 2 on which a spring-loaded drum 3 is mounted for rotation, a rotatable speed regulator 8 comprising a hub 9, which is adapted to be driven by a flange 16 of the drum, and a braking mechanism 18 for braking the drum. In order to minimize the number of parts the braking mechanism 18 and the speed regulator 8 are combined for form a single part, in such a way that the braking mechanism acts on the hub 9 of the speed regulator. For this purpose the hub 9 engages in a wedge-shaped gap 20 formed between a brake shoe 19 and the drum flange 16.

Abstract: An electrical apparatus is provided in which in the situation as shown in FIGS. 1-4 in which power inlet pins are exposed, a user can use the electric appliance by connecting A.C. cord 20 to power inlet pins 5 without danger that a user might touch slide plugs 4 because they are completely covered by slide cover 7. In this situation, if a user pushes finger actuating portion 8 of slide cover 7 in the direction as shown by an arrow in FIG. 4, power inlet pins 5 are covered by slide cover 7 and slide plugs 4 protrude out of plug slits 32 by rotation of pinion gear portion 3 which engage with rack gear 17 and 18 as shown in FIGS. 5 and 6. In this situation, the electric appliance can be charged with slide plugs 4, while power inlet pins 5 are covered by slide cover 7, so that there is no danger that a user might touch power inlet pins 5.

Abstract: A vacuum cleaner is provided comprising a housing (1) with two filter systems (2,3) arranged in series, means (4) for generating an air flow through the filter systems, the second filter system (3) as seen in the direction of flow being a cyclone filter system, which vacuum cleaner is provided with one reservoir (5) for collecting dust from both filter systems (2,3), which reservoir can be closed off with a lid (14), is suitable for accommodating a disposable dust bag (6), and is furthermore divided into two compartments (5a, 5b) by a wall (13), each reservoir compartment serving to collect separated dust from the accompanying filter system, while the wall (13) is fastened in the reservoir (5) in such a way that it can be taken out. Preferably, the removable wall (13) is fastened to the lid (14).As a result, the user can remove all the dust from the vacuum cleaner in one operation.

Abstract: The invention relates to an optical glass fibre 1 having a synthetic resin coating which consists of at least two layers 2 and 3 in which the first layer 2 is formed from an elastomer forming material which can be cured by exposure to actinic radiation, and in which the optical glass fibre exhibits a great tensile strength, a small risk of static fatigue fracture and a low ageing rate, owing to the fact that the synthetic resin composition comprises between 0.1 and 5% by weight of one or more phosphorus compounds of the following structural formula: ##STR1## wherein n has a value of 1 or 2 and wherein R represents an organic group, preferably an organic group which co-reacts during curing of the elastomer forming material and is built into the polymeric network thus formed.

Abstract: Polarization-retaining optical fibres are manufactured according to the PCVD method, in which on the inside of a glass tube and, simultaneously on at least two glass rods which are arranged inside the glass tube such that their longitudinal axes run parallel to the longitudinal axis of the glass tube, glass is deposited in layers and the glass rods are removed from the glass tube upon completion of the glass deposition process. Alternatively, a single glass rod, the radial dimensions of which in two mutually perpendicular directions are in a ratio unequal to one, i.e. elliptical, is arranged in a glass tube such that its longitudinal axis coincides with the longitudinal axis of the glass tube.

Abstract: A high-resolution electron microscope (1) comprising a detection system (11), an image processing system (13) and an effective electron source (3) ensuring a comparatively small thermal energy spread of the electrons to be emitted is suitable for executing a method for directly deriving amplitude and phase information of an object (17) in the form of an electron wave function .phi.. To this end, a number of images of an object (17) are recorded by means of a high-resolution electron microscope (1) in image planes (19) with defocus values which differ only slightly. Thus, a substantially continuous series of images is formed as a function of the defocus value, resulting in a substantially three-dimensional image area. A quasi-three-dimensional Fourier transformation is performed thereon in order to separate linear and non-linear image information for the reconstruction of the electron wave function.

Abstract: An element for use in an electrical circuit includes sub-region (11) and a second sub-region (12), which regions can contain a charge carrier gas (6) at least during operation and are separated from one another by an insulation zone (13). The insulaton zone (13) is locally interrupted by a barrier zone (15) which presents a potential barrier to the charge carriers. The first sub-region (11) is provided with a first connection (21) for deriving the potential from it. The second sub-region (12) is provided with two connections (22, 23) by means of which a current (I) can be passed through the second sub-region (12). The potential of the first sub-region (11) is found to be proportional to at least substantially the square of the current (I) passed through the second sub-region. This renders the element particularly suitable for an electrical circuit in which such a proportionality is desired.

Abstract: A workpiece comprises a substrate having a sliding surface provided with a friction-reducing coating. Such coating consists essentially of elemental carbon dispersed in a matrix formed of at least one metallic element in the proportions of 50.1 to 99.1 at % of the elemental carbon and 0.1 to 49.9 at % of the metallic element. The ratio of the metallic element to the elemental carbon differs from the stoichiometric ratio of the carbide.