A compact wearable antenna with a novel miniaturized EBG structure at 2.4 GHz for medical application is presented in this letter. The design demonstrates a robust, compact and low-profile solution to meet the requirements of wearable applications. The EBG structure reduces the back radiation and the impact of frequency detuning due to the high losses of human body. In addition, the structure improves the front-to-back ratio (FBR) by 15.5 dB. The proposed compact antenna with dimensions of 46 × 46 × 2.4 mm 3 yields an impedance bandwidth of 27% (2.17-2.83 GHz), with a gain enhancement of 7.8 dBi and more than 95 % reduction in the SAR. Therefore, the antenna is a promising candidate for integration into wearable devices applied in various domains, specifically biomedical technology.

Abstract-This paper presents a comparative review study on ultra-wideband (UWB) antenna technology for Ground Penetrating Radar (GPR) applications. The proposed antenna designs for UWB ground penetrating radar include a bow-tie antennas, Vivaldi antennas, horn antennas, planar antennas, tapered slot antennas, dipole antennas, and spiral antennas. Furthermore a comprehensive study in terms of operating frequency range, gain and impedance bandwidth on each antenna is performed in order to select a suitable antenna structure to analyze it for GPR systems. Based on the design comparison, the antenna with a significant gain and enhanced bandwidth has been selected for future perspective to examine the penetration depth and resolution imaging, simultaneously suitable for GPR detection applications. Three different types of antennas are chosen to be more suitable from the final comparison which includes Vivaldi, horn and tapered slot antennas. On further analysis a tapered slot antenna is a promising candidate as it has the ability to address the problems such as penetration depth and resolution imaging in GPR system due to its directional property, high gain and greater bandwidth operation, both in the lower and higher frequency range.

Wireless Body Area Network (WBAN) technology is gaining popularity in personal communication due to the expanding improvement in wireless technology. Wearable antennas are utilized in various WBAN applications including personal healthcare, entertainment, military, and many more due to their attractive characteristics and the potential for integrating lightweight, compact, low-cost, and adaptable wireless communications. A wearable reconfigurable antenna will allow a single antenna to operate at multiple resonant frequencies, radiation, polarization or hybrid between them, by using single or multiple active switching devices for signal transmission and reception in different parts of human body, rather than using multiple antennas. Over the years, several review papers were reported on wearable antennas which discussed the requirements and issues of wearable antennas in terms of their design, fabrication, and measurement. Nowadays, WBAN technology employs a single wearable reconfigurable antenna to perform multiple functions in different parts of human body. Recently, a significant amount of work has been carried out in the area of wearable reconfigurable antennas for WBAN applications. This paper presents a comprehensive review of the requirements and analysis needed for wearable reconfigurable antennas such as Specific Absorption Rate (SAR) for on-body analysis, investigation of the antennas in bending conditions, reconfigurable techniques and reconfigurable performance metrics.

Microstrip patch antennas are increasingly gaining popularity for usage in portable wireless system applications due to their light weight, low profile structure, low cost of production and robust nature. The patch is generally made of a conducting material such as copper or gold and can take any possible shapes, but rectangular shapes are generally used to simplify analysis and performance prediction. Microstrip patch antenna radiates due to the fringing fields between the patch edge and ground plane. In this work, a frequency reconfigurable antenna with a BAR63-02V Positive-Intrinsic-Negative (PIN) diode is designed, simulated and fabricated. The antenna operates at 2.686GHz for Long-Term Evolution (LTE2500) and 5.164GHz for Wireless Local Area Network (WLAN) applications. In the OFF state, the antenna operates at 5.302GHz, which is also suitable for WLAN application. The proposed antenna is fabricated on a FR-4 substrate with a relative dielectric constant, εr of 4.5, thickness, h of 1.6mm and loss tangent, tan δ of 0.019. The fabrication process is carried out at the Advanced Printed Circuit Board (PCB) Design Laboratory in UTHM.