Radiofrequency Waveform Synthesis with the Josephson Arbitrary Waveform Synthesizer

We have measured the frequency-dependent voltage output up to 100 MHz of a modified version of the Josephson Arbitrary Waveform Synthesizer. An impedance-matching resistor was integrated within the Josephson junction array circuit to match the nominally zero array impedance to a transmission line and a 50 Ω load. The matching resistor significantly reduces ripple in the output voltage transfer function due to reflections from impedance mismatches, but it negatively impacts the quantum accuracy of the output. The resulting transfer function is flat within 0.01 dB up to 10 MHz, above which it deviates by no more than 0.15 dB.