Injection Locking Type 1/2 Frequency Divider Employing Piezoelectric MEMS Resonator for Simplifying the Micro Atomic Clock System

This paper is the first report on injection-locking-type frequency dividers incorporating a piezoelectric MEMS resonator. It gives us a new step toward the ultraminiaturizion of atomic clocks to the chip level. Our devices can divide the 6-GHz-band RF signal to the 3-GHz-band signal with a wide range of more than 80 MHz without using complicated PLL circuitry. Since, in an atomic clock, the clock transition frequency of 87Rb is 6.8 GHz and the modulation signal of the laser required in the feedback operation is 3.4 GHz, this development makes it possible to self-oscillate an atomic clock without a lock-in-amplifier-based digital discriminator.