  An ultra-low-voltage crystal quartz oscillator is proposed. The approach to
its design is essentially based on using a HEMT operating in unsaturated dc
regime and a quartz resonator as a resonant impedance transformer. The 25 MHz
prototype shows steady oscillations at the supply voltage of less than 17 mV
and the power consumption as low as 300 nW, i.e., 1-2 orders of magnitude lower
than other to-date oscillators. This approach is good for building ultra-low
consumption radio devices including those working at low temperatures.
