The process, known as TaRFSOI (Toshiba RF SOI) is SOI-CMOS (silicon on insulator complementary metal oxide semiconductor), is an original front-end process technology that Toshiba developed for RF switch ICs.
As the performance of mobile devices including smartphones is constantly improving, their wireless frequencies are becoming higher. There are concerns that receiving sensitivity deteriorates at higher frequencies in the same manner as signal loss increases between an antenna and a receiving circuit. As a result, there is a need for the enhancement of the characteristics of LNAs in order to improve the received signal quality by compensating for signal loss.
The latest generation process (TaRF11) has been developed to make it possible to significantly improve the characteristics of low noise amplifiers (LNAs). This process offers additional enhancement to RF characteristics when compared with TaRF10 – the current generation SOI-CMOS process. A key parameter for these devices is their noise figure (NF) that compares the signal-to-noise ratio at the input and output.
TaRF11-based MOSFETs, intended for use in LNAs, achieved a minimum noise figure (NF) of 0.48 dB @ 8 GHz, an improvement of 0.3 dB compared to similar devices developed with TaRF10. In common with TaRF10, the TaRF11 process allows the LNA, RF switch and control circuit to be fabricated on a single chip.
Innovative RF switch ICs are being developed using Toshiba’s TaRFSOI process in conjunction with the group production facilities (Japan Semiconductor Corporation), allowing new products to be brought to market swiftly.
As end-use technology evolves, Toshiba said that it will continue to develop the company's in-house process to meet the market needs, including the move from 5 GHz to 7 GHz planned in the smartphone arena.
In addition, Toshiba plans to develop devices for 7 GHz to 10 GHz ultra-wide band (UWB) using the TaRFSOI process.
