Toshiba has developed the world’s smallest wireless communication module and thinnest flexible printed circuit (FPC) coupler compatible with TransferJetTM, the close-proximity wireless transfer technology. In combination and applied to mobile devices, such as smartphones, they achieve a maximum data transfer rate of 375Mbps.
Toshiba demonstrated the devices on January 20 at 2014 IEEE Radio Wireless Week (RWW), in Newport Beach, California, USA.
TransferJetTM continues to win attention as a low-power, high-speed communication standard, and is expected to find wide acceptance because of its uniquely simple approach to connectivity. Since the already high data volumes handled by individuals are expected increase explosively in the near future, TransferJetTM is a highly promising solution for high-speed communications between electronic devices in close proximity. This will fuel demand for TransferJetTM, modules and couplers that can be easily implemented in consumer products.
Toshiba’s small module, only 4.8mm x 4.8mm x 1.0mm, and ultra-thin FPC coupler, only 0.12mm thick, achieve a maximum physical layer transmission rate of 522Mbps (effective data transfer rate of 375Mbps). Module miniaturization was realized by employing 3D integration technology to embed a TransferJetTM-compatible LSI in the module substrate. Such embedding usually requires a higher module to maintain performance, but Toshiba’s advanced design capabilities enabled it to secure a low module with excellent performance. The new thin FPC coupler is fabricated with an innovative process that uses molecular bonding technology.
A potential problem with small, thin modules formed with 3D integration technology is a parasitic capacitance increase that often degrades performance. The frequency response of TransferJetTM is particularly sensitive to this, as has a wide signal bandwidth, 560MHz. Toshiba identified potential problems with parasitic capacitance, and solved them with the design of the module structure and tuning transmission signals’ waveforms inside the LSI.
The new FPC coupler is fabricated with molecular bonding technology, which secures enough adhesion of FPC by covalent bond of a thin molecular layer. The coupler is electrically evaluated with the module and excellent transmission RF signals have been observed. It has quarter thickness of conventional couplers.
This module and coupler are ideal for small, thin mobile devices, and Toshiba expects them to be widely adopted. The module is now ready for sample production and the coupler will be ready for sample production this month.
*: TransferJetTM is licensed by the TransferJet Consortium.