Pushing microwave detection toward the quantum limit requires a receiver that both amplifies signals at the atomic scale and reads them out with minimal added noise—competing demands that no single-resonator design has hitherto reconciled. To satisfy both simultaneously, we propose and theoretically analyze a dual-cavity Rydberg-atom receiver, in which a four-level electromagnetically induced transparency (EIT) medium is jointly coupled to a high-finesse optical resonator and a high-$Q$ microwave cavity, and we establish how such an architecture achieves high-sensitivity microwave reception. Proceeding from the Heisenberg–Langevin equations and optical input-output theory, we trace the sensitivity gain to a multistage amplification mechanism that admits a transparent interpretation as a sequential signal-transduction chain, along which the two resonators enhance different physical quantities and fulfill distinct functions: microwave-field preamplification and cavity-assisted optical readout, mediated by atomic quantum transduction. The receiver responsivity accordingly factorizes into the product $\mathcal{R}={\mathcal{R}}_{\text{MW}}{\mathcal{R}}_{\text{atom}}{\mathcal{R}}_{\text{read}}$, a closed-form result without counterpart in single-cavity schemes. By dissecting the three contributions, we obtain an unbounded microwave-field gain ${\mathcal{R}}_{\text{MW}}\propto \sqrt{{\mathcal{C}}_{\text{MW}}}$, an atomic conversion efficiency governed by the EIT susceptibility, and a bounded optical readout gain ${\mathcal{R}}_{\text{read}}=f\left({\mathcal{C}}_{\text{r}}\right)={\mathcal{C}}_{\text{r}}/{|1+{\mathcal{C}}_{\text{r}}{\chi }_{\text{t}}|}^2$, which peaks at the cavity-EIT matching condition ${\mathcal{C}}_{\text{r}}=1/\left|{\chi }_{\text{t}}\right|$, where the cavity resonance is aligned with the EIT transparency window. Translating these gains into sensitivity, a unified input-referred noise budget, benchmarked against cavity-free and single-cavity counterparts and spanning both the classical thermal noise floor and the atomic projection noise limit, shows the noise-equivalent power to fall as ${\mathcal{C}}_{\text{MW}}^{-1/2}$ until it meets the fundamental floors, beyond which subthermal reception calls for a cryogenic microwave cavity. Independent modulation of the optical detuning further renders the detection bandwidth reconfigurable in situ without forfeiting sensitivity. The sequential cooperativity-mediated enhancement mechanism identified here thus explains how a dual-resonator architecture reaches high-sensitivity microwave reception and provides a design strategy for future high-sensitivity Rydberg microwave receivers, with applications spanning quantum metrology, radio astronomy, and deep-space communication.

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• Open quantum systems & decoherence
• Quantum coherence & coherence measures
• Quantum information processing
• Quantum metrology