In the perspective of
human body communication through capacitive coupling, wide band
signaling has mixed blessings if it is not properly designed.
As shown in Fig. 1, the
signal strength or power on the transmitter side is an important
parameter to enable communication through human body or any object
which has good dielectric properties. The signal strength can be
altered by changing voltage or current or both on the transmitter
side and therefore driver circuit associated with capacitive plates
has an important role to play. Similarly, receiver sensitivity is
also an important parameter which could help in signal detection at
lower transmitting voltages and currents.
As shown in Fig. 2, there
is special importance of ground electrode layout compared to signal
electrode in the coplanar capacitor configuration. Both of them form
two plates of coplanar capacitor and electric field is confined in
between them starting from the signal plate and ending at the ground
plate. So the question of using single signal electrode is not valid argument.
