Abstract: A method for the contactless transmission of information between a transmitter/receiver unit and a transponder.

Abstract: An arrangement for measuring speeds between a first and a second object with the aid of microwave signals and including a microwave generator which is connected to a transmitter antenna, and two receiver antennae which are preferably placed on respective sides of the transmitter antenna for receiving microwave signals reflected against an object and each of which receiver antennae is connected to a respective receiver channel, the channels being connected to a correlator for correlating the signals received by the receiver antennae, the mutual time difference of said signals corresponding to the relative speed between the objects. According to the invention the microwave generator (11) is also connected to a respective mixer (13, 14, 15, 16) in each of the receiver channels, to which respective mixers (13-16) respective receiver antennae (6, 7) are connected.

Abstract: An apparatus for producing a single side band at systems where a signal of a certain frequency is received, frequency-shifted and reflected. The apparatus comprises a modulator (b 26), which includes only one diode (44). To the diode are applied a series of different voltage levels generated in a commutator circuit (41), which voltage levels are at least three in number. A tuning circuit (45) is provided between the diode and an aerial (25). The tuning circuit (45) is adjusted to act upon the amplitude and phase variations occurring at the diode (44) at the different voltage levels applied, so that the reflection coefficients of the diode (44) and the characteristics of the tuning circuit (45) together satisfy the condition for a single side band to be formed and transmitted from the aerial (25).

Abstract: An apparatus for synchronized signal reception wherein a first signal of frequency f.sub.o is transmitted by a first unit and is reflected by a second unit, which thus transmits the reflected second signal. The reflected signal is modulated by information which is supplied by a coding device 27 in said second unit, which coding device generates a coded pulse train 27p in the form consisting of pulses, i.e. information symbols. A pulse generator 28 is controlled by the pulse train to emit a signal with one of two frequencies k.sub.1 and k.sub.2, respectively, in dependence upon the binary state of the pulse train. The signal is divided in a frequency divider 29 to provide frequencies k.sub.1 /n and k.sub.2 /n, respectively, which are supplied to the coding device 27, causing the coding device to emit said pulses with lengths which are related to the cycle lengths of frequencies k.sub.1 /n and k.sub.2 /n, respectively. The signal generated in the pulse generator 28 with the frequencies k.sub.1 and k.sub.

Abstract: A radio communication method and apparatus for transmitting a modulated radio frequency signal from a first station to a second station wherein an information-bearing pulse train for modulating the radio frequency signal is chopped at a constant pre-selected rate, wherein a receiver at the second station receives the modulated radio frequency signal and has a detector for detecting the received radio frequency signal to provide an intelligence signal component containing the information and having a frequency corresponding to the pre-selected chopping rate, a bandpass filter tuned to the pre-selected chopping frequency for passing the above mentioned intelligence signal component while rejecting other signal components of different frequencies, circuitry for processing the intelligence signal component passed by the bandpass filter, and a circuit connected intermediate the detector and the bandpass filter for passing to the bandpass filter just those pulse signal components having a pulse width corresponding

Abstract: Devices for registration of an object and its movements in relation to another object by means of a high frequency signal transmitted from one of the objects and reflected from the other object, the reflected signal being modulated with an identification code and received back at the first mentioned object where the registration of the code takes place. To separate the reflected signal, from the first transmitted signal the frequency of the reflected signal is changed at the same time as it is reflected, the frequency change of the reflected signal being made in a way which allows the frequency of the reflected signal to be chosen according to wish, and that the frequency of the reflected signal is not equal to any of the stronger harmonic of the fundamental frequency of the first, originally transmitted signal. Thereby the reflected signal can be properly received and detected even though much weaker than the transmitted signal or any of its harmonics.