A Fully-Printed 3D Antenna With 92% Quasi-Isotropic and 85% CP Coverage

Abstract

Internet of things (IoT) applications require orientation insensitive wireless devices to maintain stable and reliable communication. For those reasons, antennas providing a wide quasi-isotropic and circular polarization (CP) coverage are very attractive. However, achieving a wide quasi-isotropic and CP coverage simultaneously is challenging. In this work, we show that properly designed sloped dipoles on a 3D structure can maximize the CP coverage (theoretically up to 100%) even with equal-phased feed to the dipole elements. We derive the conditions and present the design graphs for the optimum slope angle for the dipole elements on a 3D hexagonal-shaped package to achieve a wide quasi-isotropic and CP coverage simultaneously. Based on the proposed theory, a practical antenna has been designed and fabricated using additive manufacturing. The measured results demonstrate a 7dBisotropy of 92% and a CP coverage of 85%, which matches well with the predicted results from the theoretical analysis and full-wave simulations.

A Compact, Low-Profile, Broadband Quasi-Isotropic Antenna for Non-Line-of-Sight Communications

“…The proposed antenna shows a better CP performance compared with the other quasi-isotropic antenna designs, such as the electric and magnetic dipole combinations [2] and the folded electric dipoles [26]. In [29], the quasi-isotropic antenna for AoP applications provides radiation with a spatial CP coverage performance of 85%, which is wider than that of the proposed antenna. However, such a feature occurs only at a single resonant frequency.…”

“…In this paper, we propose an electrically small, low-profile, and highly efficient q isotropic antenna that is matched over broad frequencies from 1.8 to 4.3 GHz, or 81 To provide reliable and robust NLOS communications with less cumbersome wireless connections and battery-less sensors, it is desired for the antenna to operate in broad frequencies and radiate electromagnetic energy uniformly in all directions. Such uniform radiation characteristics could be obtained by an ideal isotropic source [13]; however, due to its non-existence nature [14], researchers instead showed a way to obtain a nearly uniform radiation pattern in the name of quasi-isotropic antennas [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. These types of antennas can be achieved using radiation pattern synthesis, such as by a combination of electric and magnetic dipoles, a different orientation of dipoles, two electric dipoles with a 90 • phase shift, etc.…”

“…It is worth noting that currently, there is no standard gain deviation for quasi-isotropic antennas in the literature, but it is usually in the range of 3 to 10.5 dB for single-frequency resonant antennas, whereas it is usually in the range of of 6 to 12.7 dB for wideband antennas [27]. Moreover, there are very few works on quasi-isotropic antennas with CP performance [26,29,30] in broad frequencies, despite its advantageous features in wireless systems, such as polarization mismatch mitigation and multi-path interference reduction [31][32][33].…”

Fully Printed 3-D Antennas With Wideband Radiation Isotropy Based on Annular Currents Models

“…A NTENNAS with quasi-isotropic radiation patterns are attracting considerable research attention because they can provide orientation insensitive communication for Internet-of-Things (IoT) devices as well as generally reduce wireless communication interruptions [1], [2], [3]. These antennas are also attractive for energy harvesting, radio frequency identification (RFID) [4], flood monitoring [5], marine animal monitoring [6], etc.…”

Fully Screen-Printed and Gentle-to-Skin Wet ECG Electrodes with Compact Wireless Readout for Cardiac Diagnosis and Remote Monitoring

“…Recent interest in telehealth, precision medicine, and the Internet of Things or Internet of Medical Things has led to an emerging trend of sending health data to smartphone apps for continuous monitoring and remote diagnosis. , Such applications require an antenna for wireless communication, which should provide a decent gain across the whole bandwidth used by communication protocols and be easily integrated with a wearable ECG system. The antenna-on-package (AoP) fully utilizes the system’s volume and expands the design freedom to provide better performance. An AoP also serves as the packaging/enclosure, which saves considerable space, weight, and cost compared to other antenna design options in the literature.…”