Abstract: An apparatus ascertains a contact area length of a vehicle tire. The apparatus has a transmission unit which has a resonator and which is set up to transmit a sensor signal at a defined frequency. A change in the frequency of the sensor signal on the basis of mechanical excitation of the resonator is indicative of a contact area length for the vehicle tire. Furthermore, the apparatus has a contact area length ascertainment unit which is set up to receive the sensor signal and to take the change in the frequency of the sensor signal as a basis for ascertaining the contact area length of the vehicle tire.

Abstract: An apparatus ascertains a contact area length of a vehicle tire. The apparatus has a transmission unit which has a resonator and which is set up to transmit a sensor signal at a defined frequency. A change in the frequency of the sensor signal on the basis of mechanical excitation of the resonator is indicative of a contact area length for the vehicle tire. Furthermore, the apparatus has a contact area length ascertainment unit which is set up to receive the sensor signal and to take the change in the frequency of the sensor signal as a basis for ascertaining the contact area length of the vehicle tire.

Abstract: Taking as a starting point known security apparatuses and their methods for distance-dependent initiation of functions in or at an object, the reliability of distance measurements is essentially increased by carrying out a series of distance measurements, an associated quality value (G) being calculated by a mathematical function in each case for the measuring results (M1–M5, R1, R2) of said distance measurements. Only those measured values which fall below a certain quality value (Krit) as a threshold value are generally accepted for an analysis in respect of initiating a distance-related function. Developments provide for selecting measured values beforehand with reference to a level measurement, in order to further increase the reliability, or applying methods of statistical analysis subsequently.

Abstract: An antitheft protection system for a vehicle (10) comprises at least one transmitting and receiving unit (12) connected to the vehicle (10), at least one code transmitter (18), which can communicate with the at least one transmitting and receiving unit (12), and at least one base unit (14), which wirelessly communicates with the at least one transmitting and receiving unit (12).

Abstract: A method for determining the position of at least one second transmitting and receiving device (3) in respect of a first transmitting and receiving device in a passive access control system operating in the GHz range, comprising the steps of using a radar method, wherein signals (f1, f2) are received in the first transmitting and receiving device on the left-hand side and right-hand side of a modulation frequency (fmod), determining the distance of two signals (f1, f2) closest to the left-hand side and right-hand side modulation frequency (fmod) wherein the distance is proportional to the distance between the first transmitting and receiving device and at least one second transmitting and receiving device (3), so that multipath propagations are not taken into consideration.

Abstract: Taking as a starting point known security apparatuses and their methods for distance-dependent initiation of functions in or at an object, the reliability of distance measurements is essentially increased by carrying out a series of distance measurements, an associated quality value (G) being calculated by a mathematical function in each case for the measuring results (M1-M5, R1, R2) of said distance measurements. Only those measured values which fall below a certain quality value (Krit) as a threshold value are generally accepted for an analysis in respect of initiating a distance-related function. Developments provide for selecting measured values beforehand with reference to a level measurement, in order to further increase the reliability, or applying methods of statistical analysis subsequently.

Abstract: A method for determining the position of at least one second transmitting and receiving device (3) in respect of a first transmitting and receiving device in a passive access control system operating in the GHz range, comprising the steps of using a radar method, wherein signals (f1, f2) are received in the first transmitting and receiving device on the left-hand side and right-hand side of a modulation frequency (fmod), determining the distance of two signals (f1, f2) closest to the left-hand side and right-hand side modulation frequency (fmod) wherein the distance is proportional to the distance between the first transmitting and receiving device and at least one second transmitting and receiving device (3), so that multipath propagations are not taken into consideration.

Abstract: An antitheft protection system for a vehicle (10) comprises at least one transmitting and receiving unit (12) connected to the vehicle (10), at least one code transmitter (18), which can communicate with the at least one transmitting and receiving unit (12), and at least one base unit (14), which can communicate with the at least one transmitting and receiving unit (12).