A Compact L-Band Bandpass Filter with RF MEMS-Enabled Reconfigurable Notches for Interference Rejection in GPS Applications

In light of today´s crowded radio spectrum and the high level of receiver sensitivity required to receive very weak signals, mitigating interference (cosite, intentional jamming, or from other sources) has become a very important topic of research. The recent controversy regarding the use of spectrum close to the global positioning system (GPS) bands is the motivation for the IEEE Microwave Theory and Techniques Society 2014 International Microwave Symposium (IMS2014) Tunable Radio-Frequency (RF) Microelectromechanical Systems (MEMS) Filter Student Design Competition, held in Tampa, Florida. Although there are frequency bands reserved for GPS, there is sometimes interference from undesired signals from a variety of sources, such as radio emissions in adjacent bands, intentional/unintentional jamming, and naturally occurring space weather. Ensuring the continuity of GPS service requires the protection of its spectrum from interference. This competition was intended to interest students in the design of innovative RF front-end solutions to address this issue. This article describes the work of the winners of the first-place award.