Substrate integrated waveguide‐based simultaneous transmit and receive antenna for full‐duplex wearable devices

Abstract

In this paper, a low‐size and compact substrate integrated waveguide (SIW)‐based simultaneous transmit and receive antenna is developed for full‐duplex wearable telemetry applications. The antenna operates at 4.9 GHz (Wireless Local Area Network [WLAN]) and 5.8 GHz (Industrial, Scientific and Medical [ISM]) bands with acceptable gains. Keeping a proper gap between the two ports achieves an isolation of better than 29.8 dB. This antenna is kept compact (0.20 λg2, where λg is the wavelength at 4.9 GHz) by additional arc‐shaped slot in each radiator, which adds additional capacitance. The suggested antenna is simulated inside a 52 × 63 × 17 mm3 dummy wearable telemetry device and is worn on the subject's chest. Thanks to SIW technology, it has unidirectional radiation patterns, allowing a minimum beam towards the human body, and thus, offers lower specific absorption rate (SAR) at both frequency bands. The unique advantage is its capacity to receive and transmit the telemetry signals simultaneously. Its low profile, flexibility in the resonant bands, simultaneous transmission and reception, and lower SAR values make this antenna suitable for full‐duplex wearable telemetry devices.

Inkjet Printed Flexible High Isolation Patch Antenna for 5.8 GHz Full-duplex Applications

“…Also, the design has comparable bandwidth and peak gain with the literature. Please note that the majority of antennas introduced are on rigid substrates (i.e., [2,3,22,37]) and are not suitable for conformal full-duplex applications. Compared to recent flexible full-duplex implementations [19][20][21]38], the proposed antenna has much higher isolation (< −50 dB) in the band of interest.…”

“…Both designs demonstrate low isolation values between TX and RX ports, making them not suitable for full-duplex systems. Another work [22] proposes a substrate integrated waveguide (SIW) based antenna operating at 4.8 GHz and 5.8 GHz with an isolation level of −29.8 dB for wearable applications. However, this antenna also lacks the necessary level of isolation as well as a more complex fabrication process than other candidates.…”

Wireless Body Area Networks and Their Applications—A Review

“…The standard monopole antenna is a typical example of this, and it can be oriented to have vertical, horizontal, or inclined polarization. However, the conventional type monopole antenna is not convenient for the user to wear in a WBAN node and therefore many researchers have developed planar linearly polarized antennas to address this issue [48], [49], [50], [51], [52], [53], [54], [55], [56]. However, single-sided planar monopole antennas for WBAN suffer from the drawback of not providing conductive shielding on its backplane and hence the characteristics change when it touched the human body [57].…”

“…They have shown through their experiments that one can vary the geometric parameters such as the gap between IDE lines or the number of IDE lines to obtain the resonating frequency of the device around 2.5 GHz. Mallat and Iqbal have proposed a waveguide-fed full-duplex antenna that can work at 4.9 GHz and 5.8 GHz compatible with both WBAN and SIW [56]. The designed antenna is 52 × 63 × 17 mm 3 in size and provided gains of 4.93 dBi and 5.97 dBi at lower and upper resonating frequencies.…”

Simple Integration of Cavity-Backed Antenna with Patch Antenna for Developing Hybrid Antenna Using SIW Technology

“…In addition, it can be used in numerous types of biomedical applications, including heartbeat monitoring [47]. Recently, SIW-backed antenna has been employed for full-duplex communication system and to develop efficient hybrid-filter subsystem [48,49].…”