technologies used to implement near-field focused antennas at the microwave frequency band up to a few tens of GHz: arrays of microstrip patches and printed dipoles, arrays of dielectric resonator antennas, reflectarrays, transmitarrays, Fresnel zone plate lenses, leaky-wave antennas, and waveguide ...
The ability to dynamically focus (or, on the contrary, homogenize) the beam at any point within the near-field region of the metasurface would make the proposed system suitable for a number of emerging applications, such as microwave absorbers, able to protect sensitive antennas or electronics ...
Near-field technology is increasingly recognized due to its transformative potential in communication systems, establishing it as a critical enabler for sixth-generation (6G) telecommunication development. This paper presents a comprehensive survey of recent advancements in near-field technology research. Fir...
Nepa P, Buffi A. Near-field-focused microwave antennas: near-field shaping and implementation.IEEE Antennas Propag Mag. 2017;59:42–53. Web of Science ®Google Scholar Miyamoto RY, Itoh T. Retrodirective arrays for wireless communications.IEEE Microw Mag. 2002;3:71–79. ...
Time-domain near-field spectroscopy: the role of hyperbolic phonons Hyperspectral THz nano-imaging31 is performed by coupling the s-SNOM microscope to a THz TDS system based on photoconductive (PC) antennas (Menlo TERA15 FC), as schematically depicted in Fig. 1a. ...
The detailed origins of the different behavior of the small and large antennas have not yet been examined, although since the peak magnetic field on axis is higher and the fall-off more abrupt for a small antenna, some difference in behavior is to be expected. ...
Fig. 5HFSS simulation of the far-field radiation patterns of all five antennas at 3.5 GHz. The near-field of a dipole antenna has a distribution of electric field intensity that is very different from that given in Equation 1 for the far-field. In the near...
the single microstrip planar antenna essentially provides low field intensity in the near-field region. To address this challenge, a near-field focused microstrip array antenna operating at 2.45 GHz is proposed for maximizing the power transmission efficiency between two antennas30. However, a large ...
Pat. No. 3,999,182 teaches such an antenna useful in aircraft landing systems operating in the microwave frequency range. Linearly phase shifted array antennas are not useful, however, in operating in the near field, and in particular, are not useful in obtaining a fixed beam focused signal...
each antenna is continuously monitored in the field in real time to measure the quality of the microwave beam. Ideally, the beam should be monitored in the far field where it is focused, that is, a distance from the antenna of at least 2D2/λ, wherein D=aperture of the transmitting dev...