Table 2.
Hardware improvement space for next generation of the prototype
| Hardware | Coil Size (cm) | PCB Size (cm) | PCB Components Number | PCB Components Density (%) 1 | Estimation of Minimised PCB Size (cm) |
|---|---|---|---|---|---|
| Transmitter | 0.8 (r) × 2.0 (h) | 7.8 × 5.0 × 1.0 | 115, of which 82 are passive components 2 | 8.11 | 4.1 × 3.0 × 1.6 (estimated with density of 50%) 3 |
| Receiver | 1.8 × 1.8 × 1.8 | 4.9 × 4.2 × 1.0 | 349, of which 257 are passive components | 14.55 | (integrated into transmitter board) |
| Battery | 7.2 × 3.5 × 2.5 | 5.4 × 3.5 × 0.6 (a common smartphone battery) | |||
| Overall | 16 × 6.5 × 6.0 | 5.4 × 3.5 × 4.1 |
The density was calculated by dividing all components’ footprints size by the PCB size, representing the components occupied area in each square centimeter of the PCB. The density of on-board connections and wires are not considered in the table, since their layout problems can be easily addressed by increasing the layer from four to six, or even eight; Passive components are single units, like resistors, capacitors, which have a small footprint of 1.0 × 0.5 or 1.6 × 0.8 mm; This components density is common for a DFM (Design for manufacturability) [36] in current consumer electric devices. For example, in the latest generations of smartphones, the component to board footprint ratio is approximately above 70% [37]. This can be further increased by new innovative PCB technologies [38].