Low profile, low cost, and multilayer Luneburg lens antenna design

This paper presents a planar Luneburg lens antenna characterized by high gain, a low profile, and low cost. Two distinct flattening methods are employed to enhance wave focusing performance. In the vertical direction, a permittivity gradient is achieved by stacking layers of materials with varying permittivity. Horizontally, the permittivity is controlled by introducing square through-holes of modulated dimensions into the cylindrical structure, which also streamlines the manufacturing process. The radius of the lens is 1–1.2 times the wavelength. The simulated and measured peak gain reaches up to 17.05 and 16.3 dB, respectively. The measured half-power beamwidth is 33° at 4.9 GHz with good focusing. Shifting the lens ±30 mm from the feed gives ±15° beam deviation and 16.2 dB peak gain, showing good beam scanning. The design and manufacturing methods enhance antenna performance and have broad application prospects.