A UHF-band RFID transmitter with spur reduction technique using a DLL-based spread-spectrum clock generator

This paper presents a UHF-band RFID transmitter with a robust spur reduction technique using a DLL-based SSCG. By adopting an 8-bit DLL and Hershey-kiss modulated profile together, the SSCG shows more than a 20dB EMI reduction while providing up-, down-, and center-spread modes. Implemented in a 0.18μm CMOS process, the proposed transmitter achieves <; -80dBc spur suppression with 25dBm transmit power at 920MHz, which complies with the most stringent regulatory spectral mask without a SAW-filter.