Josephson junction microwave modulators for qubit control
  We demonstrate Josephson junction based double-balanced mixer and phase shifter circuits operating at 6-10 GHz, and integrate these components to implement both a monolithic amplitude/phase vector modulator and a quadrature mixer. The devices are actuated by flux signals, dissipate no power on chip, exhibit input saturation powers in excess of 1 nW, and provide cryogenic microwave modulation solutions for integrated control of superconducting qubits. 
O. Naaman, J.A. Strong, D.G. Ferguson, J. Egan, N. Bailey, R.T. Hinkey
cond-mat.supr-con cond-mat.mes-hall quant-ph