Abstract: The invention relates to a linear drive unit comprising a first and second actuator element, a guiding unit configured to enable a linear relative movement between both actuator elements, a first and second power unit, each attached to the first actuator element and configured to provide the second actuator element with a respective first and second driving force, and a control unit for controlling both power units and configured to control the first and second driving force such that the first driving force can be different from the second driving force. The invention further relates to a telescope comprising a linear drive unit as well as to a method of aligning such telescope.

Abstract: A tensile strain state in semiconductor components is adjusted. A pretensioned (tensile strain) layer is applied to a substrate (FIG. 1, (A)). Bridge structures (FIG. 1, (B)) are introduced in the layers by lithography and etching. The bridges are connected to the layer on both sides and are thus continuous. The geometric shape of the bridges, formed with a cross-section modulation, is determined by the windows (FIG. 1 (C)) in the layer. When the substrate is etched selectively, the bridge is undercut through the windows. The geometric structuring of the cross-section (FIG. 1, (D)) causes a redistribution of the originally homogeneous strain when the bridges are detached from the substrate, with the larger cross-sections relaxing at the expense of the smaller cross-sections, where the pretension is increased. Only a multiplication of stresses (or strain) originally present in the sample is possible, with the multiplication factor determined by lengths, widths and depths, and/or the relationships thereof.

Abstract: A synthetic aperture radar (SAR) processes radar has a transmit aperture and a receive aperture that is of a different size from the transmit aperture. The receive aperture is separated from the transmit aperture and is divided into a number of receive sub-apertures arranged in the elevation and azimuth directions. Circuitry is used to process the received radar signal coherently by phase shifting each receive sub-aperture signal by a time and/or frequency variant phase value and by summing the resulting signals from receive sub-apertures arrayed along the elevation direction, whereby the time and/or frequency variant phase value is generated in such a way that the radar echo signal is maximized in the summed signal as the radar transmit signal runs over the earth's surface.

Abstract: The invention relates to a side-looking SAR system, comprising