26.1 A 26-to-60GHz Continuous Coupler-Doherty Linear Power Amplifier for Over-An-Octave Back-Off Efficiency Enhancement

It is envisioned that mm-wave wireless technologies will be the key enablers for 5G and beyond-5G wireless revolutions. To maximize the channel capacity, throughput, and frequency diversity, mm-wave wireless standards often mandate channels with GHz bandwidth (BW) over multiple non-contiguous bands. Also, as spectrally efficient highpeak-to-average power-ratio (PAPR) modulations such as OFDMs are widely employed, system dynamic range and linearity have become critical. Moreover, to compensate for the mm-wave path loss and enable diverse MIMO operations, there is an increasing need for complex high-density arrays with high system energy efficiency. These requirements have posed tremendous technical challenges on mm-wave front-ends, in particular PAs.