Dual-Polarized Wearable Antenna/Rectenna for Full-Duplex and MIMO Simultaneous Wireless Information and Power Transfer (SWIPT)

Abstract

<div>Owing to the mobility of a wearable antenna and the unpredictable body-centric communications environment, dual-polarization antennas are essential for both communications and energy harvesting. This paper presents a dual-polarized four-port textile antenna/rectenna for wearable simultaneous wireless information and power transfer (SWIPT) applications. The proposed antenna utilizes dual ports for both off-body communication and energy harvesting from horizontal and vertical polarizations. The antenna maintains a 100 MHz bandwidth with an S11 under -10 dB around 2.4 GHz in the presence and absence of the human body, and at least 10~dB small-signal and large-signal isolation between all ports. The antenna maintains a 70-88% measured total efficiency and 8.4--9.6 dBi gain for various on-phantom positions across both communication ports. The measured mutual coupling is under -10 dB between co-polarized rectenna/antenna ports, and under -16~dB between orthogonally-polarized ports. A high RF to DC peak power conversion efficiency of over 70% (+-5%) is achieved with a broadside harvesting pattern. Based on the proposed antenna's performance, SWIPT microstrip antennas can be adopted for both full-duplex and MIMO applications, significantly reducing the complexity of future battery-free networks for both wearable and non-wearable applications.</div>

Battery-Free Wireless Node Powered using High-Efficiency Harvesting of 900 MHz GFSK-Modulated Packets with a Compact Rectenna

“…Beyond theoretical networking studies [2], the practical implementation of SWIPT can be divided into a rectenna and rectifier design problem, and a signal and waveform design problem. Multiple rectennas including dual-band microstrip SWIPT rectennas [3], single-band dual-polarized RFID tags [4], and full-duplex multi-in multi-out (MIMO) [5] SWIPT antennas/rectennas have been proposed based on shared aperture multi-port antennas which do not need a matching network. Furthermore, hybrid couplers have been proposed for optimal power-splitting for rectennas involving the use of 50 Ω-matched antennas and rectifiers [6].…”

Body-Proximity Effects on the Input Impedance of a Complex-Conjugate SWIPT Textile Rectenna

“…Recently, a range of fully textile wearable SWIPT rectennas has been proposed based on shared-aperture multi-port antennas [5], [7]. For a microstrip patch with a solid ground plane [7], the rectenna's impedance is mostly maintained in human proximity.…”

“…Recently, a range of fully textile wearable SWIPT rectennas has been proposed based on shared-aperture multi-port antennas [5], [7]. For a microstrip patch with a solid ground plane [7], the rectenna's impedance is mostly maintained in human proximity. However, for the unisolated "wire-type" dipole rectenna [5], the influence of human proximity on the rectifier's complex conjugate matching remains unknown.…”

Optimum Antenna Characteristics for Maximally Harvesting Ambient RF Energy

“…Several approaches emphasize design aspects, such as polarization, number of ports, frequency bands or tones, and spatial arrangement [11][12][13][14][15][16][17][18][19][20][21]. Indeed, recently, a two-port dual linearly-polarized (LP) bowtie-shaped meander dipole A FIGURE 1.…”

“…Another example considered a four-port patch antenna with two integrated T-shaped slots. This antenna had two LP ports to receive and transmit simultaneously (full-duplex) while harvesting wireless power on two other LP ports [12]. Besides, other works focused on circular polarization (CP), trying to receive right-hand (RH) and left-hand (LH) CP signals on two ports separately over a single design.…”