  This paper proposes a cost-effective architecture for an RF pulse generator
for superconducting qubits. Most existing works use arbitrary waveform
generators (AWGs) that require both a large amount of high-bandwidth memories
and high-performance analog circuits to achieve the highest gate fidelity with
an optimized RF pulse waveform. The proposed pulse generator architecture
significantly simplifies both the generator circuit and the waveform of the RF
pulse to a cost-aware square pulses. This architecture eliminates the
requirement for power- and cost-intensive AWG, a major obstacle in realizing
scalable quantum computers. Additionally, this paper proposes a process to
optimize pulse waveforms to maximize fidelity of gate operations for single and
multiple qubits. Quantum dynamics simulation of transmon qubits, wherein the
state of system evolves with time, demonstrates that our pulse generator can
achieve practically the same gate fidelity as ideal RF pulses, while
substantially reducing the performance requirements of memory and analog
circuits.
