A solid-state atomic frequency standard

This paper describes a new class of frequency reference. The frequency source uses the same operating principle as a passive atomic frequency standard; however, the device is entirely solid-state, removing many cost and reliability issues associated with gas phase atomic clocks. More specifically, the "atomic resonance" is derived from zero-field magnetic resonance transitions of the vanadium ion in magnesium oxide. The characteristics of these resonances will be described in detail. The apparatus for measuring the "atomic" resonances uses a microwave resonant cavity and frequency-discriminator circuit. Using integrated circuits, the radio-frequency signal processing functions can be implemented at very low cost in a reliable manufacturing process. We discuss the system design and the measurement sensitivity. The estimated short term stability is in the range of 10^-8 to 10^-9 @ 1 s. Advantages of the new frequency reference may include immunity to vibration, reduced aging compared to crystal oscillators, and immediate cold start.