  Coherent charge-photon and spin-photon coupling has recently been achieved in
silicon double quantum dots (DQD). Here we demonstrate a versatile split-gate
cavity-coupler that allows more than one DQD to be coupled to the same
microwave cavity. Measurements of the cavity transmission as a function of
level detuning yield a charge cavity coupling rate $g_c/2\pi$ = 58 MHz, charge
decoherence rate $\gamma_c/2\pi$ = 36 MHz, and cavity decay rate $\kappa/2\pi$
= 1.2 MHz. The charge cavity coupling rate is in good agreement with device
simulations. Our coupling technique can be extended to enable simultaneous
coupling of multiple DQDs to the same cavity mode, opening the door to
long-range coupling of semiconductor qubits using microwave frequency photons.
