Juneseok Lee

Realistic Head Phantom for Evaluation of Brain Stroke Localization Methods Using 3D Printer

In this paper, a brain phantom for evaluating brain stroke localization is proposed. To evaluate brain stroke localization, a phantom imitating three-dimensional (3D) simulation environment is needed. Mold for the proposed phantom was printed by a 3D printer and the interior of the phantom consists of 5 different brain tissue materials. Each of the brain tissue materials has the conductivity and permittivity similar to those of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) standards for a frequency band from 0.5 to 2 GHz.

Design of an antenna for brain stroke localization

This paper proposes an antenna for brain stroke localization. To diagnose brain stroke with microwave, broadband low frequency electromagnetic pulse is required. The proposed antenna consists of an elliptical radiating patch, two slots, and high pass filters to generate the aforementioned pulse. The proposed antenna has 10 dB return loss bandwidths from 0.7 GHz to 2 GHz (high frequency band) and from 0.518 GHz to 0.525 GHz (low frequency band). The propagation characteristics of the electromagnetic pulse inside brain tissue are also analyzed.

Design of a low profile UWB antenna for wearable applications

A low profile UWB antenna for wearable application is proposed. To accomplish the wideband characteristic, an elliptical patch, tapered feeding structure, and vias are adopted. The proposed antenna has a wide 10-dB return loss bandwidth of 5.6 GHz (2.9 GHz - 5.2 GHz and 7.1 GHz - 10.4 GHz). It can simultaneously cover low and high UWB bands (3.4 GHz - 4.8 GHz and 7.25 GHz - 10.25 GHz).

Design of a Modified Alford Loop Antenna for On-Body Devices

In this paper, a modified Alford loop antenna for on-body communication system is proposed. The proposed antenna operating in the ISM band is designed with consideration of human body effect. One of advantages of the Alford loop antenna structure is lowprofile, however the Alford loop antenna is not suitable for on-body devices since it does not have a ground plane for other electronic part of on-body system and requires balanced feeding structure. To be embedded on on-body devices, the proposed antenna is design with the unbalanced feed structure and ground. The performance of the proposed antenna is simulated and measured when it is placed on the human body phantom to consider the effect of the human body. The proposed antenna a 10 dB return loss bandwidth over the ISM band and monopole-like radiation pattern with low-profile. The antenna has the surface of appropriate for on-body communication environment.

A Tapered Slot Antenna with Asymmetric Corrugations for a Microwave Brain Imaging System

Recently, a brain imaging system with microwave devices has been proposed. The brain imaging system requires a small antenna which has ultra wide band(UWB) operating frequency bandwidth(0.5~2 GHz) and non-varying boresight of antenna over the frequency band. This paper proposes asymmetric corrugations on a tapered slot antenna (TSA) so that the size of the TSA is reduced by 14 % while 10 dB return loss bandwidth is satisfied over the operating frequency band from 0.5 GHz to 2 GHz. A miniaturized TSA with symmetric corrugations shows tilted boresight whilst frequency is getting lower; however, the proposed TSA with asymmetric corrugations maintains direction of boresight for different frequencies. This enhancements make an asymmetric corrugated TSA meet the requirement of the brain imaing system.