SAW-Less Digitally-Assisted Receivers

Today’s wireless devices, like our smartphones, are able to handle multiple standards and bands for different applications, such as Bluetooth, Wi-Fi and data-voice communications. However, the cost of a modern transceiver is becoming mainly dominated by the large number of off-chip passive components, like Duplexers and SAW filters, needed to distinguish the desired signal among many interferences. Addressing the challenges that arise from the lack of RF filtering, a SAW-less architecture represents an interesting solution to reduce the platform complexity. This thesis proposes a feasible solution based on a SAW-less RF front-end able to meet the standard requirements and a digital system tailored to the RF path. The digital architecture, which represents the main topic of this thesis, is described in detail and experimentally tested to validate the proposed solutions

A low power control system for real-time tuning of a hybrid transformer-based receiver

none4noThis paper presents the analysis and hardware implementation of a low-power control system for a frequency-division duplexing 3G receiver with a tunable on-chip duplexer based on a hybrid-transformer. The maximum transmit-receive isolation exceeds 60dB and is limited by the precision of the on-chip balancing impedance. An optimization algorithm finds the optimal duplexer tuning condition in less than 100μs and a simple tracking algorithm operating in background preserves this condition over time. The algorithms are implemented in a FPGA and require minimal hardware overhead.Castellano, G.; De Caro, D.; Strollo, A.G.M.; Manstretta, D.Castellano, G.; De Caro, D.; Strollo, A. G. M.; Manstretta, Danil