an active aerial for use in car radios and aerial &# 34 ; arrays &# 34 ; comprising an aerial element and an aerial connected thereto . in order to obtain a low distortion and a good signal - to - noise ratio in spite of the presence of protection diodes to prevent overloading of the amplifier by atmospherics and in spite of contamination of the aerial etc , the input of the active portion of the amplifier is virtually grounded . to this end , the amplifier is preferably an operational amplifier having a high gain factor , the signal input of which is connected to ground , both the signal coming from the aerial element and a signal fed back from an output of the amplifier being applied to the inverting signal input .