A 1.4 GHz radio frequency source with low phase noise and fast modulation for cold atom experiments

We present a radio frequency source based on the AD9914 direct digital synthesizer chip, with a frequency range up to 1.4 GHz. The phase noise at an output frequency of 1 GHz is lower than −110 dBc/Hz at a 10 kHz offset. Through an optimized design of a field-programmable gate array, we have achieved the theoretical maximum modulation rate of AD9914 and developed multiple functional modules for cold atom experiments to implement modulation of frequency, phase, and amplitude. The modulation update rate reaches 146 MHz. The phase modulation response latency is 158 ns, and the amplitude modulation response latency is 95.1 ns. We have applied the RF source to a sideband Pound–Drever–Hall locking experiment and achieved frequency stabilization, demonstrating its suitability for cold atom experiments that require precise and complex laser control.