A communications apparatus is provided. The value n is an integer greater than or equal to 1 for the oligomer and greater than or equal to 0 for the phthalonitrile monomer. The van elements, with a radially inner end region, are accommodated in the inner rotor in a radially displaceable manner and, with a radially outer end region, are accommodated in the outer rotor in a pivotable manner. The amplifying elements 11 and 21, the choke inductors 12 and 22, the by-pass capacitors 13 and 23, and the resistive element 37 are formed on the same substrate.