IPS GaAs FET proximity sensors from Micro Oscillator Inc., Bala Cynwyd, PA, are radiation-hardened by design, using GaAs FET transistors. The sensors can be built using bipolar, FET, or MOS style transistors from most semiconductor process technologies. Additional ruggedness is assured by using passive component (R, C, L) ratios. Transistor gain variations and DC leakage currents have minimal effect and the operating voltage is in the 2–3 V range. Circuit implementation is designed for input sensing flexibility; one or more inductors can be used in the circuit and tuned to respond between various metals or tuned to a specific metal.
Micro Oscillator Inc.