Millimeter Wave All-Around Antenna Based on Whispering Gallery Mode Dielectric Resonator for IoT-Based Applications

Abstract

This work is devoted to the study of the emitting properties of azimuthally inhomogeneous segmental dielectric resonators excited by whispering gallery modes. Due to the diffraction of the azimuthal waves on local nonhomogeneities located equidistantly along the azimuthal coordinate, intense electromagnetic radiation is achieved in the azimuthal sector of the angles 0°-360°. A prototype of an all-around emitting antenna based on basis of a segmental dielectric resonator is proposed, and its characteristics in the far zone are studied. It is shown that such an antenna forms a multilobe radiation pattern (72 lobes) in the circle sector of angles. The antenna gain in the lobes at the resonant frequency reaches 12 dB. Antenna optimization is achieved in the proposed method because of the large gain produced by the antenna. It is also analyzed that these types of radiation patterns observed by antennas are well used for the Internet of Things- (IoT-) based applications.

Visualizing the Nanoscopic Field Distribution of Whispering-Gallery Modes in a Dielectric Sphere by Cathodoluminescence

“…However, the visualization of the fields associated with WGMs is still limited to simulations of the circulating waves, despite the fact that such field distributions are essential to investigate, customize, and apply WGMs. In this context, there are just indirect observations, such as the redistribution of the field in optical sensing by a silica microtoroid resonator when perturbed by an external molecule, or the radiation patterns of an antenna along the rim of a segmental dielectric disk resonator . Moreover, field imaging is currently limited to only externally taken photographs of the associated waves, as demonstrated by microscope images of stopped light that display the interference patterns of the field along the surface of a fused silica microsphere .…”

“…In this context, there are just indirect observations, such as the redistribution of the field in optical sensing by a silica microtoroid resonator when perturbed by an external molecule, 3 or the radiation patterns of an antenna along the rim of a segmental dielectric disk resonator. 16 Moreover, field imaging is currently limited to only externally taken photographs of the associated waves, as demonstrated by microscope images of stopped light that display the interference patterns of the field along the surface of a fused silica microsphere. 17 It is hence worth noting that, despite the fact that the distribution of whispering-gallery fields has been used to analyze the underlying mechanisms in designing efficient WGM-based applications, an experimental acquisition of the optical fields of WGMs that directly visualize the distribution of the internal field inside a resonator has not yet been realized.…”