A Local Oscillator for Chip-Scale Atomic Clocks at NIST

We describe the first local oscillator (LO) that demonstrates viability in terms of performance, size, and power, for chip-scale atomic clocks (CSAC) and has been integrated with the physics package at the National Institute of Standards and Technology (NIST) in Boulder, CO. This voltage-controlled oscillator (VCO) achieves the lowest combined size, DC power consumption, phase noise, and thermal frequency drift among those previously reported, while achieving a tuning range large enough to compensate for part tolerances but small enough to permit precision locking to an atomic resonance. We discuss the design of the LO and the integration with the NIST physics package.