A tunable RF filter for multistandard GSM/UMTS/WiFi/LTE receiver

The tunable RF filters are considered as a promising solution which can be implemented in the front-end RF of Software Defined Radio (SDR) receivers to make them suitable for multistandard wireless applications in a cost-effective and power-efficient way. In this paper, a tunable RF filter based on Dual-Behaviour Resonators (DBR) topology and excited by varactors as tuning components is presented. This filter is designed to operate in next generation transceivers using GSM, UMTS, Wi-Fi and LTE wireless standards. Special attention will be paid to the varactor model and its impact on the filter performance. S parameters simulations show a good agreement with the standards specifications in terms of center frequencies and bandwidths.