In this paper, an approach towards the realization of a hybrid MEMS-CMOS RF oscillator module using the novel silicon-ceramic (SiCer) compound substrate technology is described. Piezoelectric aluminium-nitride MEMS resonators with quality factors Q up to 2,200 and resonant frequencies of 240, 400 and 600 MHz have been investigated as frequencyselective elements. For RF-compatible hybrid-integrated assembly and packaging, the SiCer compound substrate has been adapted, promising an efficient integration of both, microelectronic and micromechanical devices, on a single carrier substrate. Multiphysical circuit design and simulations using parametrized behavioural MEMS models have been carried out, indicating stable oscillator operation at the design frequency. As one prospective application, such an oscillator module could form part of a compact and power-efficient reconfigurable RF transceiver frontend in SiCer technology, e.g., for mobile communications.