Wideband Tunable Bandstop Filters Based on High Reliability MEMS Varactors

Co-site interference is a common source of jamming aboard naval vessels where several high power systems such as radars and electronic warfare equipment are co-located on same mast or in close vicinity of communication systems. High power transmissions from these systems act as local source of jamming and can be disruptive to the function of the communication radios also operating in the same environment. A hardware approach for mitigating the effects of co-site interference is to equip the nearby receivers with bandstop filters that are capable of suppressing these jammers. Due to the wide frequency range and dynamic nature of the interference, these bandstop filters must be tunable in a wide frequency range and have an adjustable bandwidth and attenuation. Furthermore, they must be highly linear and capable of withstanding large levels of RF power. Existing tunable filter technologies are generally lacking in both respects. The objective of this STTR project is to develop a wideband fully tunable bandpass filter solution to address this need. Freeform Wave Technology, LLC, and University of California, San Diego, have teamed up to develop a new generation of MEMS based bandstop filters that are expected to reach unprecedented levels of RF performance, tunability, and power handling. High reliability MEMS varactors developed by UCSD will be the key enabling technology in these filters.