The present invention relates to new compoundsor salts, solvates or solvated salts thereof, processes for their preparation and to new intermediates used in the preparation thereof, pharmaceutical compositions containing said compounds and to the use of said compounds in therapy. For reader standby mode, reader circuitry in the system’s preamplifier is transitioned to a low-power mode during write operations. One arrangement of the detuning unit includes two varactor diodes connected anti-parallel between the antenna terminals. According to one aspect of the invention, at least one of the keys or functions includes a nonlinear function.