Microelectromechanical Systems for Radio Frequency Channel Switching (Review)

Introduction . In view of the growing demand for the quality and linearity of RF signal switches, microelectromechanical system (MEMS)-based switches (MEMS-SW) are attracting particular interest. Such devices offer several advantages over other technologies. This article examines the operational and manufacturing specifics of MEMS-SWs, including fabrication and sealing technologies, degradation mechanisms, and design improvements expected to enhance the device performance. Quantitative parameters of commercially available MEMS-SWs are presented. Aim. To review MEMS switch design, production, and factors influencing their mass adoption. Materials and methods . The literature review follows a chronological approach. For evaluating end-component parameters, sources published over the past 10 years were prioritized, while technologies and structural solutions were traced over longer periods to document the evolution of MEMS switches. The final dataset comprised peer-reviewed publications with factual data and official manufacturer specifications. Results . Key characteristics, production and packaging technologies, and required testing methods are described. Materials for MEMS-SW fabrication are analyzed, along with known degradation mechanisms and mitigation strategies. Design solutions for enhancing the performance and parameters of current MEMS-SW are discussed. Conclusion . Although MEMS switch structural components are relatively affordable due to the similarities of fabrication processes with CMOS technology, MEMS-SWs costs remain significantly higher than those of transistor and PIN diode switches, primarily due to packaging and testing expenses. MEMS-SWs outperform electromechanical relays in most applications and are preferable for solid-state switches when linearity and FOM are critical, rather than the size or the switching speed. Continued market growth and performance improvements are anticipated.