Wide steering 128QAM direct digitally modulated E-Band time modulated array transmitter

A new, joint use, of RF switchable phase inverting TX hardware and time modulated array (TMA) signal processing control is demonstrated at 73 GHz. The techniques control beam steering and apply direct digital modulation. The system provides increased steering range of the modulated beam, compared to prior works. Beam pattern and constellation results for 32QAM and 128QAM are presented. Using the highest power radiating beam, 32QAM is demonstrated beam steering over ±60 degrees. With 128QAM, beam steering of ± 40 degrees is achieved. The practicality of applying predistortion to improve the TX constellations is also demonstrated, to mitigate hardware imperfections. The proposed TX QAM TMA can simplify future mmWave transmitters, by providing beam steering and direct digital symbol modulation in one module.