A multipath technique for canceling harmonics and sidebands in a wideband power upconverter

Switching mixers are power-efficient but produce unwanted harmonics and sidebands. A multipath technique to clean up the spectrum using digital circuits and mixers, but no filters, is applied to a 0.13μm CMOS power upconverter. The circuit delivers 8mW from dc to 2.4GHz with 11% drain efficiency, with spurs <-40dBc over more than 4 octaves in frequency, and consumes 228mW from a 1.2V supply