Beam Optimization for 28 GHz Phased Array Utilizing Measurement Data

This paper presents beam optimization methods for a phased array operating at 28GHz. The phase of each antenna element is controlled with an element-specific 5-bit phase shifter. The amplitude of each element varies with the chosen phase shift state due to the antenna design. Each individual element is measured and based on the measurement data, the beam optimization for the maximum gain is done. The optimization increases the measured gain compared to the nominal case by 1.3dB at broadside. Furthermore, the element amplitude variation allows optimization for the lower side lobes to be done by finding the correctly weighted amplitudes. Taylor distribution is used for this optimization and the side-lobe level decreases 2.4dB for the broadside beam.