Semiconductor switches Providing Linearity And Speed at High-power (SPLASH)

Recent advances in semiconductor technology have drastically reduced the on-resistance off-capacitance product (Ron.Coff) and increased the breakdown voltage density of the FET switch. These improvements have resulted in lower insertion loss, higher isolation, and power handling capabilities. However, conventional RF FET switches suffers from poor decoupling between the control signal and large RF signals passing through the switches. This decoupling determines when the switch self-actuates in the presence of a large RF signal. The conventional solution to this problem is to use a diplexer (large resistor on the gate of the FET) which severely limits the switching speed. Therefore, a trade-off exists between the switching speed and linearity or power handling (defined by 1 dB or 0.1 dB compression point) of the conventional switch.Lintrinsic’s innovation is in the FET switch’s control decoupling circuit that solves the switching speed - linearity trade-off. With this innovation, a high voltage control signal actuates a FET switch, resulting in increased power handling, similar to the MEMS technology. Furthermore, the conventional diplexer is eliminated, making the switching speed independent of the RF frequency passing through the switch. The switching speed, bandwidth, and power handling capability of the FET switch in this innovation is determined by the high-voltage switch driver which is orders of magnitude faster than the maximum switching frequency of traditional FET switches with similar power handling. The innovation can be applied on stacked SOI CMOS and GaN because of the isolating substrate and excellent Ron.Coff constants. In addition, a FET switch implemented in stacked SOI CMOS or GaN has performance across a broad range of metrics (bandwidth, switching speed, power handling, insertion loss, isolation, hot switching, and reliability) comparable to or better than that of other RF switch technologies like a mechanical relay, MEMS, phase change, solid state plasma, and PIN diodes.