Hybrid Transformer-Based Adaptive RF Front End for UHF RFID Mobile Phone Readers

We introduce hybrid transformer-based adaptive RF front end for UHF RFID readers. Small, narrow band antennas with high radiation efficiency can be utilised with an adaptive tuning of the antenna. The adaptivity also increases immunity to environmental changes, like detuning of the antenna by user hand. The hybrid transformer-based front end provides high isolation from TX to RX and eliminates the need for a cumbersome and expensive circulator. The small size of the module including the antenna enables integration to mobile phones.