Digital I/Q Sharing mm-wave Transmitters for WiFi
While some attempts have been made to realize digital PAs at mm-wave bands, most demonstrations to date have produced relatively low resolution transmitters and are more suitable for simple modulation schemes. Here we propose a new architecture which can generate 64-QAM using basic I/Q unit elements. For 16-QAM, only 3 are needed, while 64-QAM requires 7 units. Each unit is driven by a constant power signal from the VCO. A series of injection locked VCOs can be used to drive sufficient power without incurring passive losses, and one of these VCOs can be part of a phase-locked loop to generate a low phase noise reference. No phase modulation is necessary in this architecture as it is a Cartesian transmitter, with I/Q bits fed into the unit elements. This is important in mm-wave applications since the arctan non-linearity multiplies the bandwidth of an I/Q signal to 7X or more when considering the phase path in a polar transmitter.
Expected Graduation Date:
May, 2026
