Patent ID: 8185048

Claim:
A communication apparatus comprising: a transmitter configured to supply an information signal as an electric field to a transmission medium; a receiver configured to detect the electric field through the transmission medium to acquire the information signal; an insulating casing that accommodates at least one of the transmitter and the receiver; and a filling member that is arranged at least one of between an internal surface of the casing and the transmitter accommodated in the casing and between the internal surface of the casing and the receiver accommodated in the casing, wherein at least one of the transmitter and the receiver accommodated in the casing includes an electrode arranged so as to face the internal surface of the casing, wherein the filling member fills a gap between the electrode and the internal surface of the casing, and wherein part of the casing facing the electrode includes a thin wall portion such that a volume ratio of the filling member with respect to the casing between the electrode and the internal surface is increased.