New approach to design tunable RF filters using DBR topology for SDR receivers

Reconfigurable RF filter in Software Defined Radio (SDR) receivers is a promising solution to reduce analog circuit size especially in case of multi-standard radio context. In this paper, a new approach to design tunable RF filters using dual behavior resonators (DBR) topology is proposed. This design methodology is performed to design an electrical tunable filter able to switch between UMTS, WiFi and LTE reception bands. The designed filter is simulated using FR4 microstrip technology. S parameter simulation results show good agreement with standard specifications in terms of filter center frequencies, bandwidths and selectivity.