A 1 GHz 27 mW Low-Power Direct Digital Synthesizer for RF Carrier Signal Generation in Trapped-Ion Quantum Computer Operating at 9.4K

This paper presents a 1 GHz low power Direct Digital Synthesizer (DDS) with sub-Hertz frequency resolution operating at 9.4 K. The proposed circuit is used as a signal generator for microwave (MW) driven qubit entanglement operations in trapped-ion quantum computers for improved gate fidelity. This is realized by utilizing the generated waveform as the carrier for the qubit’s driving signal. This signal is further frequency multiplied and envelope modulated to get the final qubit driving signal. The proposed mixed-signal-circuit operates at a 2.5 V/1.5 V analog and 1.5 V digital supply, 1 GHz input clock and consumes a total power of 27.64 mW. The frequency normalized-total power consumption, is only 27.64 µW/MHz. The DDS gives a worst case narrow band SFDR of 32.72 dB across the octave of frequencies to be synthesized. The design is manufactured in a 0.13 µm SiGe BiCMOS technology and has a core area of 0.69 mm².