Abstract: A communication system using a length shift keying (LSK) modulation method provides a transmitter having a carrier signal generator for generating carrier signals, and a modulator for modulating lengths of the carrier signals from the carrier signal generator according to combinations of data bits, and a receiver having an integrator for calculating an energy value by integrating the carrier signal that corresponds to a data bit combination, and a data judgment unit for judging the data bit combination by comparing the energy value with a predetermined threshold value. Power is maintained without changing the bandwidth of a communication signal when the communication signal is modulated.

Abstract: The operating method is based on the simultaneous application of FM and AM. In this process, the fundamental frequency of the AM is derived from at least one, preferably the second, longitudinal mode. In continuous operation of the lamp, the color temperature is set for a prescribed power by setting the AM degree controllably.

Abstract: A method and apparatus for wireless data transmission between a base station and one or more, in particular, passive and/or backscatter-based transponders, in which the base station modulates a carrier signal with a modulation signal, to generate synchronization markers, and transmits the modulated carrier signal. Whereby, a frequency of the modulated carrier signal can be switched between different frequency values.

Abstract: Amplitude modulator comprising a differential input pair receiving a modulating input signal, and a Gilbert cell multiplying a carrier signal by the modulating input signal; anda second differential pair of transistors receiving the carrier signal, and the output signal of which is added to the output signal of the Gilbert cell.