Beam Steering Limitations for Sequentially Rotated Circularly Polarized Phased Antenna Arrays

In this paper, the effect of sequential rotation on the beam steering capabilities of a circularly polarized phased antenna array is analyzed. Two different topologies for a phased antenna array operating at Ka-band between 28 GHz and 40 GHz are studied where each structure is tailored to produce a maximum gain of almost 19 dB with an axial ratio below 0.5 dB. The individual elements of both topologies are dual fed with a differential phase shift of 90° respectively. This paper proves that the steering capability of a phased antenna array is doubled when sequential rotation is omitted from its feeding network.