  We report a technique that can noninvasively add multiple DC wires into a 3D
superconducting microwave cavity for electronic devices that require DC
electrical terminals. We studied the influence of our DC lines on the cavity
performance systematically. We found that the quality factor of the cavity is
reduced if any of the components of the electrical wires cross the cavity
equipotential planes. Using this technique, we were able to incorporate a
quantum dot (QD) device into a 3D cavity. We then controlled and measured the
QD transport signal using the DC lines. We have also studied the heating
effects of the QD by the microwave photons in the cavity.
