US Patent 10560076 Frequency generation in a quantum controller

A quantum controller comprises quantum control pulse generation circuitry, signal generation circuitry, and phase parameter generation circuitry. The phase parameter generation circuitry is operable to determine, based on an output of the time-tracking circuitry, a first value of a phase parameter to be used for generation of an oscillating signal. The signal generation circuitry is operable to, at a first time instant, begin generation of the oscillating signal at a first frequency for modulation of a first of the two quantum control pulses, and, at a second time instant, generate the oscillating signal at a second frequency, wherein the phase of the oscillating signal at the second time instant is determined by the value of the phase parameter such that the phase of the oscillating signal is as it would have been if the oscillating signal had been oscillating at the second frequency continuously since a reference time.