Abstract: In one embodiment, an antenna device includes a scanning reflector, a fixed feeder interacting with the reflector for emitting radar radiation and a detector for detecting reflector passage of at least two different predetermined scanning positions during scanning of the reflector. The antenna device also includes a timer used to determine passage times at the time of reflector passage of the scanning positions. The scanning position of the reflector is predicted at an arbitrary time on the basis of the passage times and a predetermined scanning motion of the reflector. In another embodiment, a method for determining an accurate scanning position for the scanning reflector of the antenna device is disclosed.

Abstract: The invention relates to a process for determining the relative velocity in the radial direction between two moving objects, using linear frequency modulation with continuous frequency sweeps. A problem in such processes lies in being clearly able. to determine the phase difference. According to the invention, a clear determination is realized by varying the period. length for successive frequency sweeps and using the difference in period length and corresponding phase change in determining the volocity.

Abstract: The present invention relates to a method for classifying objects detected by a vehicle mounted radar located in front of said vehicle for transmitting a radar microwave signal and for receiving reflexes thereof from objects positioned in front of said vehicle, said melted comprising the steps of: tracking a radar reflex from an object located in front of said vehicle as the calculated distance from said vehicle to said object, as derived based upon the time of flight of said radar reflex, decreases; monitoring changes in the amplitude of said radar reflex from said object is said calculated distance from said vehicle to said object decreases; and classifying said object as an overhead object or a ground level object based upon the said changes in the radar reflex amplitude.

Abstract: A method and an apparatus for controlling a radar oscillator for use in the traffic field, in particular for a car radar, for generating a linear frequency sweep. A phase-locked linearization loop generates a linear frequency sweep controlling a phase-locked oscillator loop, which has a considerably broader bandwidth than the linearization loop.

Abstract: In a method for tracking a radar target the imaginary part of the complex elevation error signal is utilized and the value of the complex elevation error signal is calculated for a plurality of frequencies in a repeated sequence. The value change between the different frequencies is used for determining the position within an unambiguous interval and the values calculated at the zero crossing are utilized as measure of the inclination which in turn is compared with inclinations calculated for zero crossings in a general case, whereby a single-valued (unambiguous) interval and position can be determined and thereby the associated elevation angle or target height can be calculated. The method is specifically useful for tracking at low height where multi-path propagation poses a problem in tracking according to known methods.