Abstract: The invention relates to a microwave antenna for the generation of a beam with adjustable parameters. Use is made of a reflective Fresnel zone plate that is written into a thin layer of silicon by means of a laser plus deflection means. A reflector is positioned behind the Fresnel zone plate for reflecting microwave radiation that is not reflected by the Fresnel zone plate.

Abstract: Radar apparatus provided with a transmit generator and antenna means for the transmission of comparatively long, linearly frequency-modulated transmitter pulses. Echo signals are received by antenna means and a heterodyne signal is generated in mixer stage. Propagation time differences for different echo pulses are compensated by means of a dispersive delay element incorporated in the radar receiver. Distortion of the echo pulses in the dispersive delay element is corrected on the basis of a Fresnel ripple correction. A Fourier transformation unit transfers the corrected echo pulses to time domain video with low sidelobes.

Abstract: A microwave vector modulator (4) of the reflective type is used to match a microwave load. The adjustable reflection of the vector modulator is obtained by semiconducting surfaces (18, 19, 20, 21), illuminated by light-emitting means (24, 25, 26, 27).

Abstract: An antenna system provided with an adjustable reflection coefficient includes at least one radiation source (1), a reflective surface (12) positioned in the path of the radiation generated by the active radiation source (1) and 9 light-generating means (13, 14). The reflective surface (12) is provided with semiconductor surfaces (2.i.j) with a spacer-therebetween and the light of the light-generating means (13, 14) is used to illuminate the semiconductor surfaces (2.i.j) such that, after reflection of the radiation generated by the active radiation source at the reflecting semiconductor surfaces, a radiation beam is obtained in which the beam width and beam orientation can be varied by adjusting the light intensity so as to adjust the phase of the reflection of the semiconductor surfaces.

Abstract: The antenna system is provided with at least one active radiation source (1) and a reflective surface (2), which is located in at least one part of the radiation (3) generated by the active radiation source (1). The reflective surface (2) is provided with a number of independently adjustable plates (2.j) for generating at least one radiation beam. The antenna system may be provided with means (4) to independently adjust the plates (2.j) for the purpose of (dynamically) orientating the antenna beam.

Abstract: An FM-CW radar apparatus is provided with: a transmitter unit (1, 2, 3) for the emission of frequency-modulated continuous carrier waves of bandwidth B; a receiver unit (6, 7) for the reception of echo signals reflected by a target, producing target-representing beat signals; a signal processing unit, to which the beat signals are applied, provided with: an A/D converter unit (8) for the sampling and digitization of the beat signals; a first FET processing unit (10) with the object of obtaining at least range information about a target; a second FET processing unit (12) with the object of obtaining at least high resolution information about a target; a control unit (13), which makes the output signals, generated by the first FET processing unit (10) and the second FET processing unit (12), suitable for presentation on a display (14).

Abstract: The invention relates to an FM-CW radar apparatus where the frequency sweep duration (R) corresponding with the transmitted signal is increased to obtain a mixing signal which is operational in a wider frequency range than the frequency sweep of the transmitted signal. This has the effect that processing of echo signals of sufficient length can be realized, also from objects which are located near the limits of the radar range.

Abstract: A pulse radar apparatus is provided with a first receiver (4) connected to a directional antenna (3) and a second receiver (13) connected to an omnidirectional antenna (12). The receivers (4, 13) are suitable for reception and processing of long-duration and short-duration radar signals respectively, whereby at least the long-duration signals are frequency-modulated and subjected to pulse compression. The radar apparatus is further provided with a side-lobe blanking circuit (20) and switching means (25, 26).

Abstract: A high power pulsed laser set-up comprising a laser-tube and a generator, screened at least transversely from the environment, by a housing that forms a conductor for one of the electrodes of the tube.