Equivalent output impedance of a transmitter-human body system as viewed from a receiver for human body communication

When a transmitter for human body communication is worn by a human user, this transmitter-human body system can be regarded as a signal source as viewed from a receiver that is in contact with the human body. We evaluated the equivalent output impedance of this signal source, which is an important parameter for front end design of a receiver. The impedance was capacitive and the value was in the order of several kΩ at 10 MHz. The impedance was smaller when the capacitive coupling between the human body and the environment was larger.