• DOI:10.1103/PhysRevApplied.17.034008
• Corpus ID: 235794984

Connection between Antennas, Beam Steering, and the Moiré Effect

@article{Mcguyer2021ConnectionBA,
  title={Connection between Antennas, Beam Steering, and the Moir{\'e} Effect},
  author={Bart H. Mcguyer and Qi Tang},
  journal={Physical Review Applied},
  year={2021}
}

• B. Mcguyer, Qi Tang
• Published 9 July 2021
• Business
• Physical Review Applied

Electromagnetic antennas are a vital and ubiquitous technology in modern communication systems and a multitude of other applications. With a long history, research and development continues to create novel antennas and to improve their designs. The challenges of nextgeneration communication systems still drive much of this work. For example, systems that plan to use continuously moving satellites in constellations or high-altitude platforms will need sophisticated ground-based user antennas to continuously track and switch between moving terminals. Developing low-cost and low-power user antennas for those systems is one of many areas of current interest. There is a connection between antennas and the moiré effect that is known in optics [1–3] but does not seem to be as appreciated or utilized in radio, microwave, or mm-wave applications. This connection exists if spatial interferences play a key role in the internal functions of an antenna, for example, to generate and dynamically control beams. The moiré effect is a general name for the production of such spatial interference patterns on surfaces when structures like two-dimensional images are combined [4, 5]. Well-known moiré patterns include the large-scale interferences that occur when nearly identical repetitive structures are superposed, such as the parallel lines or curvilinear rulings shown in Fig. 1. Additional examples include aliasing, Glass patterns from aperiodic or random structures, and small-scale interferences like rosettes and dot trajectories. The moiré effect has many applications, from strain measurement to superresolution microscopy, in part because it can magnify small differences or repetitive structures [4–9]. Recently, it has been used to control the properties of bilayer graphene [10] and of metamaterials [11, 12]. In this paper, we make the connection between antennas and the moiré effect explicit and, as an example, illustrate how beam steering can be generated and controlled by moiré patterns. We begin with background on the relationship between antennas, Fourier analysis, and beam steering and adapt this background to discretized antennas (i.e., slot and phased arrays). We then illustrate how the dynamic beam steering of four antennas can be modeled as moiré patterns, two of which are potential candidates for next-generation satellite constellation user terminals [13, 14]. One of these candidates is our recent experimental work [14] towards a low-cost and low-power phased-array antenna. Finally, we examine two additional moiré patterns relevant to beam steering, and conclude with a discussion of potential areas for