Multiphase EXOR frequency mixers

Digital frequency mixing using EXOR gates requires minimal design effort and circuitry, and it can be easily included in any standard-CMOS integrated circuit. It suffers, however, from an output spectrum highly populated by strong spurious products. This work introduces the concept of multi-phase EXOR mixing as an approach to reduce spurious content while maintaining design simplicity. Theory is supported by measurements using an FPGA implementation.