Figure 11
From: Enabling Covert Body Area Network using Electro-Quasistatic Human Body Communication
Quasi-static Leakage (QSL) Measurement Set-up with the wearable EQS-HBC device, using an antenna and an oscilloscope. (a) Leakage from the device hand is measured with the device arm extended towards the antenna tip and moving away from/towards the antenna. Distance (d) is measured between the antenna and the device. This figure shows measurement for d = 0+ (very close to the antenna, but not touching it). Gradually, the device hand is moved further away from the antenna in two directions (θ = 0, 90) and the leakage signal is measured and sent to the PC for further BER/correlational analysis. (b) Similarly, leakage from the free hand is measured with distance (d) between the free hand tip and the antenna tip. This figure shows measurement for d = 0+. Note that during the free hand leakage measurement, it is away from the body as well as the device hand to ensure that the leakage from the EQS-HBC device arm do not affect the free arm leakage measurements. (c) The shielded wearable EQS-HBC transmit device is shown. It consists of the interfacing band with the copper electrode (signal electrode) which couples the transmitted signal into the body. (d) Inside the shield is the ARM Cortex M4 based microcontroller (TivaC) which transmits the data.
