Abstract: A method for detecting and correcting non-linearities in radio-frequency, voltage controlled oscillators provides for digitization of the frequency signal by feeding the undelayed frequency signal and a delayed frequency signal generated therefrom into EXOR gates. The digital pulses produced thereform are converted using a low pass filter into a proportional DC voltage value which is proportional to the oscillator frequency and is used as a basis for producing a correction value for the frequency control of the oscillator.

Abstract: Signals are emitted with a FMCW sensor system, are received after reflection at targets and are processed to form a measured signal whose frequency spectrum is analyzed. Discrete, equidistant samples are stored and are arranged in a double Hankel matrix in the existing sequence. This matrix is diagonalized with a singular value decomposition, and an approximation is identified taking only the “principle values” into consideration, in order to calculate the frequencies and their amplitudes therefrom according to known methods.

Abstract: A radar sensor device for detecting the distance and/or the speed of an object relative to the sensor device is provided with an oscillator, which can be frequency detuned through the use of a modulation function. The radar sensor device has a power switch, which can be driven by a power control function, for varying the transmitter power. The sensor device is to be operated in an alternating fashion, through the use of a variable setting of the modulation and power control functions, in at least two different, mutually overlapping operating modes which are tuned to different measuring ranges of the sensor device.

Abstract: Anti-theft protection system for a motor vehicle, and a method for operating an anti-theft protection system. The anti-theft protection system has a transmitting and receiving unit in the motor vehicle, which transmits radar signals modulated over a broad bandwidth and then waits for echo signals. A code transmitter, which receives a radar signal, for its part sends back an additionally modulated and coded signal. An evaluation unit analyses all the received echo signals firstly for authorization of the code transmitter and secondly in order to determine the distance between the code transmitter and the transmitting and receiving unit.

Abstract: An FMCW sensor in which a transmission signal is generated from a high frequency of a fixed frequency oscillator and a modulated, low frequency of a second oscillator. The modulated frequency is processed in a delay line with a surface wave component to form a reference signal. A transmission mixer with a hybrid coupler having a 90° phase difference and terminated by diodes is employed in a transmission/reception means. A measured signal from the transmission mixer together with the reference signal is interpreted in an evaluation means.

Abstract: A method in which a sensor system with a frequency-modulated signal source an a delay line for generating a time-delay reference signal is implemented. Phase errors are compensated by correcting the modulation (pre-equalization derived from the reference signal. Signals with a long running time are measured and additionally compensated by a computational, subsequent elimination (post-equalization). A high-pass filter is provided to that end.

Abstract: FMCW doppler radar, in which a reference signal is generated from the transmit signal via a delay line and a mixer. A measuring signal which is received and mixed with the transmit signal is detected and digitized at the times of the zero crossings of the reference signal. In this way, the measuring signal can be evaluated at time intervals of equal phase of the reference signal. A downstream algorithm enables the generation of a strictly linearly frequency-modulated transmit signal. With this mechanism, phase errors of conventional radar systems are eliminated.

Abstract: Anti-theft protection system for a motor vehicle, and a method for operating an anti-theft protection system. The anti-theft protection system has a transmitting and receiving unit in the motor vehicle, which transmits radar signals and then waits for echo signals. A code transmitter, which receives a radar signal, modulates this signal and sends it back. An evaluation unit analyses all the received echo signals firstly for authorization of the code transmitter and secondly in order to determine the relative interior/exterior position of the code transmitter with respect to the motor vehicle.

Abstract: Microwave radar: an additional modulation of the microwave signal (s (t)) provided for the emission or of the reception signal (e (t)) makes it possible to separate the payload signal from the noise signal parts in a following demodulation and filter unit (HP, MI2, TP). To this end, a modulation unit (MO, RG) for suitably modulating the signal to be emitted is provided preceding the antenna (A). The undesired noise signals produced by the components of the radar sensor itself are not modulated and can therefore be separated from the payload signal by filtering. This separation ensues after a raw measured signal (mess' (t)) has been generated by mixing transmission and reception signal (MI). A renewed demodulation with the modulation signal (r t)) of the modulation unit supplies the final measured signal (mess2 (t)) determinant for the determination of the distance, whereby the noise signals are previously removed by high-pass filtering and/or are subsequently removed by low-pass filtering.

Abstract: A signal source produces a frequency-modulated signal. The signal is supplied to a transmit/receive unit and transmitted. A surface-wave element produces a signal delayed by a delay from the frequency-modulated signal. A mixer mixes the delayed signal with the received signal and outputs the mixed signal to an evaluation device. The delay is preferably equal to the propagation time of a signal on the measurement path. The coherence length of the ranging apparatus is thereby substantially improved.

Abstract: In the case of this radar sensor, a phase shifter is inserted between a microwave generator and an antenna and can be switched over between two phases. A demodulator (DM) demodulates the received reflected signal, which has superimposed on it the microwave signal which originates from the microwave generator. A de-multiplexer (DEMUX) which is connected downstream of the demodulator (DM) separates the two phase-shifted demodulated signals. The measurement result is largely noise-free.

Abstract: When measuring speed over ground by means of microwave Doppler radar, signal noise, switching spikes and nearby reflectors reduce the measurement accuracy. In order to avoid these disadvantages, a reference signal which recurs with the period T.sub.0 and a target signal which follows the reference signal after a time interval T.sub.s are emitted via an antenna. That part of the reference signal which has already been received again during transmission of the target signal is subtracted from the target signal which is received later. The difference signal obtained in this way is a measurement signal from which interference spikes, signal noise and nearby reflectors have been largely removed.

Abstract: In order to improve the phase noise and the temperature stability of a dielectric resonator oscillator, the cylindrical dielectric resonator which is important for the oscillation frequency is mounted on the substrate standing on its curved surface rather than lying on its end face, as conventionally customary. It is coupled to the RF lines in a higher mode (TM.sub.xxx mode) rather than in the fundamental mode (TE.sub.01.delta. mode).

Abstract: In order to sample high-frequency signals, it is necessary to have a needle pulse train and a needle pulse train which is inverted with respect thereto. By means of a switch (T) which is controlled by a clock signal (U), a positive operating voltage (U.sub.B+) is applied for a limited period of time to a first conductor (L.sub.1) and a negative operating voltage (U.sub.B-) is applied for a limited period of time to a second conductor (L.sub.2). The two conductors (L.sub.1, L.sub.2) are connected via a respective diode (D.sub.1, D.sub.2), which are biased differently, to a respective resistor (RV.sub.1, RV.sub.2), which is connected to ground, and to a respective capacitor (C.sub.1, C.sub.2). The respective capacitors connected to a respective further resistors (RL.sub.1, RL.sub.2), which is connected to ground, the needle pulse train being present at one resistor and the needle pulse train which is inverted with respect to the first being present at the other resistor.