Radio frequency mixing modules for superconducting qubit room temperature control systems

As the number of qubits in nascent quantum processing units increases, connectorized RF (radio frequency) analog circuits used first generation experiments become exceedingly complex. The physical size, cost and electrical failure rate all limiting factors extensibility control systems. We have developed a series compact mixing boards to address this challenge by integrating I/Q quadrature mixing, IF(intermediate frequency)/LO(local oscillator)/RF power level adjustments, DC (direct current) bias fine tuning on 40 mm $\times $ 80 4-layer PCB (printed circuit board) board with EMI (electromagnetic interference) shielding. module is designed work LO frequencies between 2.5 8.5 GHz. typical image rejection adjacent channel isolation are measured be $\sim$27 dBc $\sim$50 dB. By scanning drive phase loopback test, short-term amplitude linearity typically 5$\times$10$^{-4}$ (V$_{\mathrm{pp}}$/V$_{\mathrm{mean}}$) 1$\times$10$^{-3}$ radian (pk-pk). operation was validated it into room temperature system superconducting processor executing randomized benchmarking characterization single two qubit gates. single-qubit process infidelity $9.3(3) \times 10^{-4}$ two-qubit $2.7(1) 10^{-2}$.