Estimation of the Parameters of Focused Beams at Short Distances for Antennas of Diffraction Radiation at the Millimeter-Wave Band
Sergiy Provalov,
Yuriy Sydorenko,
Sergiy Shylo
Issue:
Volume 10, Issue 2, December 2022
Pages:
16-24
Received:
20 November 2022
Accepted:
17 January 2023
Published:
30 January 2023
Abstract: The article considers the results of experimental studies of the parameters of focused beams formed in W-band planar antennas of diffraction radiation using an axial dielectric lens and at focal lengths from tens of centimeters to several meters. The focusing of the beam was carried out utilizing a set of replaceable dielectric lenses with a calculated focusing distance of 1,5 m, 3 m, and 6 m. The focusing mode was also considered with two lenses installed in series, jointly providing focusing of the beam at a distance of about 0,8 m. Evaluation of the operating parameters of an electrodynamic system consisting of a planar dielectric waveguide and a planar diffraction grating both located near an inhomogeneity in the form of a dielectric layer with a variable profile (thickness), which is an axial dielectric lens, was the main aim of the researches, as well as the effect of this inhomogeneity on the quality of the formed focused beams under conditions of changes in the distance (depth of field) in the imaging mode, when the beam is inflected from the lens axis, as well as when the operating frequency changes over a wide range of values. In the course of the research, it was found that dielectric lenses with an axial profile made of high-quality polystyrene or PTFE provide the parameters of focusing antenna beams for the developed antennas of diffraction radiation following theoretical calculations, both in the focusing depth and in the mode of beam inflection from the lens axis up to 9 while changing the frequency in the range of 84100 GHz. In this case, the level of the measured side lobes in the generated beams practically did not differ from the similar values obtained for these antennas during their measurement in the open space (in the far-field zone). At a focal length of 75 cm, the transverse dimension of the focused beam was estimated as 35 mm, which approximately corresponds to the radiation wavelength and demonstrates a high focusing quality approaching the theoretically possible diffraction limit and also indicates a weak influence of the inhomogeneity in the form of a dielectric lens on the electrodynamics properties of the antenna of diffraction radiation.
Abstract: The article considers the results of experimental studies of the parameters of focused beams formed in W-band planar antennas of diffraction radiation using an axial dielectric lens and at focal lengths from tens of centimeters to several meters. The focusing of the beam was carried out utilizing a set of replaceable dielectric lenses with a calcul...
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