A liquid-crystalline media comprising one or more compounds of formula S where the parameters have the meaning defined in claim 1, and one or more compounds of the formula I and one or more compounds of the formula II or one or more compounds of the formula I and one or more compounds of the formula III or one or more compounds of the formula II and one or more compounds of the formula III or one or more compounds of the formula I and one or more compounds of the formula II and one or more compounds of the formula III: in which the parameters have the meaning indicated in claim 1, and to components comprising these media for high-frequency technology, in particular phase shifters and microwave array antennas.