Two coupled microresonator systems with instantaneous nonlinear index can exhibit self-pulsing behavior and could be used as all-optical integrated microwave generators. The frequency of the RF signal is limited by the photon lifetime of the resonators. For oscillations at tens of GHz, semiconductor microdisks with moderate quality factors (≈10^4) can be used. We show here that using an optimized design the frequency of the generated signal is not sensitive to microresonator resonance frequency fluctuations. Furthermore, it is possible to process the generated microwave signal in the optical domain by cascading integrated optical filters.