Abstract: An apparatus for calibration of an electronic instrument, such as a vector network analyzer, includes a number of calibrator connector elements for connection to the instrument, and a plate element including a plurality of calibration waveguide structures. The plate element has conductive surfaces, and the calibrator connector elements and conductive surfaces include periodic structures disposed with respect to each other such that gaps are formed between them. An interface enables interconnection of a waveguide of a calibrator connector element, a waveguide of the instrument, and a calibration waveguide structure. The apparatus includes a driving unit and controller for moving the plate element and/or the calibrator connector element to connect the calibrator connector element to different calibration waveguide structures.

Abstract: An apparatus for calibration of an electronic instrument, such as a vector network analyzer, includes a number of calibrator connector elements for connection to the instrument, and a plate element including a plurality of calibration waveguide structures. The plate element has conductive surfaces, and the calibrator connector elements and conductive surfaces include periodic structures disposed with respect to each other such that gaps are formed between them. An interface enables interconnection of a waveguide of a calibrator connector element, a waveguide of the instrument, and a calibration waveguide structure. The apparatus includes a driving unit and controller for moving the plate element and/or the calibrator connector element to connect the calibrator connector element to different calibration waveguide structures.

Abstract: A detecting unit is provided, including a transmitter arranged to emit electromagnetic radiation, having a frequency in the range of 0.1 to 10 THz, towards a paper web moving in a printing unit; a receiver arranged to receive electromagnetic radiation being transmitted through or reflected by the paper web and to create a signal representing the received radiation; and a controller having an input channel for receiving the signal and a calculating unit for determining a measure relating to the properties of the paper web from the signal.