A measuring device comprises a microwave transmitter, a microwave receiver, at least one antenna, a control device and a dielectric extension. The dielectric extension is disposed between the antenna and an object to be investigated. The control device controls the microwave transmitter and the microwave receiver. The microwave transmitter transmits a microwave signal by means of the antenna and the dielectric extension into the object to be investigated. The object to be investigated scatters the microwave signal. The microwave receiver receives the scattered microwave signal by means of the antenna and the dielectric extension. The length and the dielectric constant of the dielectric extension in this context are dimensioned in such a manner that the object to be investigated is disposed in the remote field of the antenna.
