The effects of water on an on-body monopole diversity antenna pair at 1800MHz

This paper presents the effect of water on a pair of 1.8GHz on-body diversity monopole antennas mounted on the forearm of a sitting male static volunteer. Application of a water layer to the forearm was seen to both reduce efficiency and increase directivity leading to a slight overall increase in gain. Increased gain was shown to increase antenna correlation thereby reducing diversity gain in the antenna pair

A study of perturbations in linear and circular polarized antennas in close proximity to the human body and a dielectric liquid filled phantom at 1.8 GHz

In the design and synthesis of wearable antennas isolation distance from the body is a critical parameter. This paper deals with the comparison of perturbations caused to the matching of simple linear and circular polarized patch antennas due to the close proximity of a human torso and rectangular box phantom filled with muscle simulating liquid at 1.8GHz. The isolated variable is return loss (S11). Results show that both linear and circularly polarized antennas produce an optimal return loss closer to the surface of a typical phantom than the back of a human volunteer

Wet environmental conditions affecting narrow band on-body communication channel for WBANs

© 2018 Old City Publishing, Inc. Wireless Body Area Networks (WBANs) are rising as the key building blocks of next generation networks in modern health care systems. Research in recent years has focused on channel modelling, energy conservation and design of efficient Medium Access Control (MAC) schemes for WBANs. However, less attention has been paid to the on-body channel propagation analysis. This paper presents the propagation effects of wet clothing on the on-body channel at 0.9GHz, 1.8GHz and 2.5GHz and is germane to signal budgets in body-centric and mobile communication systems. A number of transmission measurements between simple monopoles above a square ground plane, placed on the opposing shoulder and hip, wearing single and multi-layered “rainwater wet” and dry cotton T-Shirts for standing, bending, torso left and right are used to gain insight into general levels of the effect of rainwater on propagation. Measured results are statistically processed to extract the level of transmission enhancement due to a wet on-body channel. Results show that wet clothing is generally beneficial to the channel at popular mobile communications frequencies

A study of perturbations in linear and circular polarized antennas in close proximity to the human body and dielectric liquid filled rectangular and a cylindrical phantom at 1.8 GHz

In the design and synthesis of wearable antennas isolation distance from the body is a critical parameter. This paper deals with the comparison of perturbations caused to the matching of simple linear and circular polarized patch antennas due to the close proximity of a human torso and rectangular box and cylindrical phantoms filled with muscle simulating liquid at 1.8GHz. The isolated variable is return loss, S11(dB). Results show that at these frequencies a cylindrical phantom resembles the body more closely than a rectangular phantom

A study of perturbations in linear and circular polarized antennas in close proximity to the human body and dielectric liquid filled rectangular and a cylindrical phantom at 1.8 GHz

In the design and synthesis of wearable antennas isolation distance from the body is a critical parameter. This paper deals with the comparison of perturbations caused to the matching of simple linear and circular polarized patch antennas due to the close proximity of a human torso and rectangular box and cylindrical phantoms filled with muscle simulating liquid at 1.8GHz. The isolated variable is return loss, S11(dB). Results show that at these frequencies a cylindrical phantom resembles the body more closely than a rectangular phantom

Characterization of on-body communication channel for vertical and horizontal polarization of center fed dipole at GSM frequency

While designing a wearable antenna for on-body communications, particular importance is given to lessen the lossy effects of the human body on transmission coefficient. This paper presents experimental and simulation results for two different polarizations of center-fed dipole antenna on human body at mobile communication frequency. The isolated parameter is S21(dB). Early results suggest that vertical polarization of dipole gives better transmission coefficient than horizontal polarization

Bandwidth Enhancement through Fractals and Stacking of Microstrip Antenna for Ku-Band Applications

One of the major constraints of a microstrip antenna is its narrow bandwidth. This paper demonstrates the influence of a dual layer staked configuration with the effect of fractal designs on a microstrip square patch antenna, for attaining both wide bandwidth and high gain properties. The proposed design of the antenna in stacked structure shows a total impedance bandwidth for S11<-10dB of 2.56GHz (18.97%) in Ku-band for satellite communication and has dual frequency bands from 11.53GHz to 13.15GHz (1.62GHz) and 15.63GHz to 16.57GHz (0.94GHz) around the resonant frequencies of 12.31GHz and 16.19GHz respectively. The intended design exhibits a 6.39dB gain whereas the radiation efficiency is up to 93.60%. These qualities of wide bandwidth and higher efficiency make the proposed antenna an excellent candidate for satellite based applications