Wide-band signaling

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.