Abstract: In a method for suppressing interferences while detecting objects in a target area, a transmitter transmits a sequence of pulses into the target area, and a receiver detects the resulting reflection signal of the pulses reflected from the objects, within successive time windows that are referenced to the moment of transmitting an individual pulse and thus represent distance gates. The time spacing between the successive individual pulses is variable and randomized according to the pseudo-noise principle within predetermined limits, and the time windows are adapted accordingly. The received reflection signal may be sampled, digitized, digitally pre-processed and digitally filtered in the individual distance gates. A non-linear digital filter, preferably a sliding median filter, is used for the filtering to suppress transient disturbances. The median is determined from an odd number of consecutive sampled values of a reflection signal detected within a distance gate.

Abstract: Input values are non-linearly digitally filtered to produce as an output value the Rth-largest value among the K input values, wherein the Rth-largest value may be the median value with R=(K+1)/2. The input values are provided in any binary fixed point number representation. A respective selected bit of all the input values is evaluated to determine the Rth-largest bit value of this bit among the K input values, and this gives the value of the corresponding bit of the output value. In the input values of which the selected bit does not correspond to the determined Rth-largest bit value, all of the subsequent less-significant bits are set as dummy bits equal to the selected bit, which excludes these input values from being the Rth-largest value in the subsequent evaluation of the successive less-significant bits. Then these steps are repeated for the next selected less-significant bit, and so forth, thereby respectively determining the successive bits of the output value.

Abstract: Circuits generate an IQ voltage or current signal having orthogonal I- and Q-parts of approximately equal amplitude from an electric input signal having a frequency varying slightly around a carrier frequency, without needing a complex mixer. The circuit includes at least one ohmic resistance and at least one reactance connected in series (for a voltage) or in parallel (for a current). The reactance has an impedance at the carrier frequency approximately matching the resistance value of the ohmic resistance. The I- and Q-parts of the voltage signal are tapped as voltage drops across the resistance and the reactance. With two such series circuit branches in parallel, both voltage signal parts can be referenced directly to a reference potential, e.g. ground. The I- and Q-parts of the current signal are tapped as currents flowing through the resistance and the reactance. The circuit can be integrated at the output of a bandpass filter.

Abstract: In a method for suppressing interferences while detecting objects in a target area, a transmitter transmits a sequence of pulses into the target area, and a receiver detects the resulting reflection signal of the pulses reflected from the objects, within successive time windows that are referenced to the moment of transmitting an individual pulse and thus represent distance gates. The time spacing between the successive individual pulses is variable and randomized according to the pseudo-noise principle within predetermined limits, and the time windows are adapted accordingly. The received reflection signal may be sampled, digitized, digitally pre-processed and digitally filtered in the individual distance gates. A non-linear digital filter, preferably a sliding median filter, is used for the filtering to suppress transient disturbances. The median is determined from an odd number of consecutive sampled values of a reflection signal detected within a distance gate.