Adaptive RF Front-Ends as a Key Enabler of Modern Communication Systems

Traditional SAW filters and duplexers, limited to fixed frequency characteristics, can only support frequency-division duplexing (FDD). However, emerging communication technologies like in-band full-duplex (IBFD) and Sub-Band non-overlapping Full-Duplex (SBFD) demand more versatile Radio-Frequency Front-Ends (RFFEs). Especially for User Equipment (UE), cost-efficient architectures with low power consumption and monolithic integration capabilities are crucial. Adaptive RF front-ends, featuring tunable filtering technologies and Electrical Balance Duplexer (EBD) architectures, enable high transmit-receive isolation for both FDD and IBFD modes. These tunable front-ends provide a power-efficient alternative to Software-Defined Radios (SDRs), allowing real-time adjustment of uplink and downlink frequencies. Additionally, reconfigurable architectures can adapt to environmental changes, such as antenna impedance variations, while integrating self-interference cancellation techniques. The presentation will explore current applications of EBDs, recent advances in silicon implementations, and developments in tunable filters for cellular and mobile communications.