  We present measurements of a hybrid system consisting of a microwave
transmission-line resonator and a lateral quantum dot defined on a GaAs
heterostructure. The two subsystems are separately characterized and their
interaction is studied by monitoring the electrical conductance through the
quantum dot. The presence of a strong microwave field in the resonator is found
to reduce the resonant conductance through the quantum dot, and is attributed
to electron heating and modulation of the dot potential. We use this
interaction to demonstrate a measurement of the resonator transmission spectrum
using the quantum dot.
