Fig. 5: Piezo-resonator and matching circuit.
From: Ultra-low-noise microwave to optics conversion in gallium phosphide
Circuit representation of the electrical side of the gallium-phosphide transducer. The 50-Ω source impedance is shown in the blue area on the left. To the right, in the green region, is the piezo-resonator. This is formed of the capacitance between the superconducting plates (\({C}_{{{{{{{{\rm{res}}}}}}}}}\)), in parallel with the effective RLC-circuit formed by the electrically-active mechanical mode. On resonance with the mechanical mode, the circuit dissipates energy into the effective resistor Rm. This process can be made more efficient by impedance matching the load to the 50-Ω-source, by using a resonant LC circuit (red region) formed of a high-impedance spiral inductor (Lmatch) and the parasitic capacitance to ground (Cmatch), featuring additional resistive loss Rloss.
