This paper presents a review of the thin film resonator technology as it relates to wireless and other RF instrumentation. Included in the discussion are emerging aspects of wireless systems and the mutual impact of miniature filters and resonators. Enabling aspects of the thin film resonator (TFR) technology will be described as applied to RF systems. Specific examples of resonators and filters will be given along with relevant performance data. The important packaging problem is described in the context of device performance and manufacturing. Wireless networks are growing rapidly in the spectrum from 500 MHz to 6 GHz. These systems include pager, cellular phone, navigation, satellite communication, and various forms of data communication. Other electronic systems have need for frequency control devices beyond 6 GHz. The need for high performance frequency control devices has become more apparent as spectrum crowding increases with use and the deployment of new systems into old spectrum allocations. Accordingly, there is a growing need for front-end filters that protect receivers from adjacent channel interference and output filters that limit the bandwidth of transmitter noise. Within subsystems, miniaturization of RF components is needed to accommodate increased levels of circuit complexity. Finally, newer system architectures require higher performance frequency control components.