  A design of LEGO-like construction set that allows assembling of different
linear arrays of three-dimensional (3D) cavities and qubits for circuit quantum
electrodynamics (cQED) experiments has been developed. A study of
electromagnetic properties of qubit-3D cavity arrays has been done by using
high frequency structure simulator (HFSS). A technique for estimation of
inter-qubit coupling strength between qubits embedded in different cavities of
cavity array, which combines Hamiltonian description of the system with simple
HFSS simulations, has been proposed. A good agreement between inter-qubit
coupling strengths, which were obtained by using this technique and directly
from simulation, demonstrates the suitability of the method for more complex
qubit-cavity arrays where usage of finite-element electromagnetic simulators is
limited.
