Super‐high‐frequency‐band injection‐locked two‐divider oscillator using thin‐film bulk acoustic resonator

Abstract

Abstract An injection‐locked divider oscillator that converts a 6‐GHz‐band signal into a 3‐GHz‐band signal was developed. The injection‐locked divider oscillator was specifically designed to lock on the clock transition frequency of 87Rb of 6.824 GHz to provide a laser modulation signal at 3.417 GHz for an on‐chip coherent population trapping atomic clock system. To obtain high frequency stability and low‐phase noise with low power consumption in the super‐high‐frequency band, a thin‐film bulk acoustic resonator is used instead of the conventional LC tank circuit. The fabricated oscillator operated well with a power consumption of 4.5 nW. The maximum lock range was 1.5% in fractional frequency. Also, unlike the conventional injection‐locked divider oscillator with an LC tank, the bifurcation of the lock range width was observed when sweeping the injection power of the 6‐GHz‐band signal, and in the down sweep, the locking operation was maintained even at an injection power of −20 dBm.

Keywords

• Mechanical effects of light
• Laser beam modulation, pulsing and switching; mode locking and tuning
• Oscillators
• Acoustic wave devices
• Laser beam modulation, pulsing and switching; mode locking and tuning