Evaluation of biasing and protection circuitry components for cryogenic MMIC low-noise amplifiers

Millimeter-wave integrated circuits with gate lengths as short as 35 nm are demonstrating extremely low-noise performance, especially when cooled to cryogenic temperatures. These operate at low voltages and are susceptible to damage from electrostatic discharge and improper biasing, as well as being sensitive to low-level interference. Designing a protection circuit for low voltages and temperatures is challenging because there is very little data available on components that may be suitable. Extensive testing at low temperatures yielded a set of components and a circuit topology that demonstrates the required level of protection for critical MMICs and similar devices. We present a circuit that provides robust protection for low voltage devices from room temperature down to 4 K.