The term photonic crystals appears because of the analogy between electron waves in crystals and the light waves in artificial periodic dielectric structures. During the recent years the investigation of one-, two-and three-dimensional periodic structures has attracted a widespread attention of the world optics community because of great potentiality of such structures in advanced applied optical fields. The interest in periodic structures has been stimulated by the fast development of semiconductor technology that now allows the fabrication of artificial structures, whose period is comparable with the wavelength of light in the visible and infrared ranges.

http://ieeexplore.ieee.org/iel5/6354/16969/00781867.pdf

Photonic crystals

Electromagnetic Metamaterials: Transmission Line Theory and Microwave Applications. By Christophe Caloz and Tatsuo Itoh.

Space-Time Block Coding for Wireless Communications

In general, Micropower Impulse Radar (MIR) depends on Ultra-Wideband (UWB) transmission systems. UWB technology can supply innovative new systems and products that have an obvious value for radar and communications uses. Important applications include bridge-deck inspection systems, ground penetrating radar, mine detection, and precise distance resolution for such things as liquid level measurement. Most of these UWB inspection and measurement methods have some unique qualities, which need to be pursued. Therefore, in considering changes to Part 15 the FCC needs to take into account the unique features of UWB technology. MIR is applicable to two general types of UWB systems: radar systems and communications systems. Currently LLNL and its licensees are focusing on radar or radar type systems. LLNL is evaluating MIR for specialized communication systems. MIR is a relatively low power technology. Therefore, MIR systems seem to have a low potential for causing harmful interference to other users of the spectrum since the transmitted signal is spread over a wide bandwidth, which results in a relatively low spectral power density.

/pdf/response-to-fcc-98-208-notice-of-inquiry-in-the-matter-of-3attixctl7.pdf

Response to FCC 98-208 notice of inquiry in the matter of revision of part 15 of the commission's rules regarding ultra-wideband transmission systems

We present a flexible, compact antenna system intended for telemedicine applications. The design is based on an M-shaped printed monopole antenna operating in the Industrial, Scientific, and Medical (ISM) 2.45 GHz band integrated with a miniaturized slotted Jerusalem Cross (JC) Artificial Magnetic Conductor (AMC) ground plane. The AMC ground plane is utilized to isolate the user's body from undesired electromagnetic radiation in addition to minimizing the antenna's impedance mismatch caused by the proximity to human tissues. Specific Absorption Rate (SAR) is analyzed using a numerical human body model (HUGO) to assess the feasibility of the proposed design. The antenna expresses 18% impedance bandwidth; moreover, the inclusion of the AMC ground plane increases the front to back ratio by 8 dB, provides 3.7 dB increase in gain, in addition to 64% reduction in SAR. Experimental and numerical results show that the radiation characteristics, impedance matching, and SAR values of the proposed design are significantly improved compared to conventional monopole and dipole antennas. Furthermore, it offers a compact and flexible solution which makes it a good candidate for the wearable telemedicine application.

Flexible and Compact AMC Based Antenna for Telemedicine Applications

An optimization technique for microstrip patch antenna using particle swarm optimization (PSO) with curve fitting is introduced in this paper. An inverted E-shaped microstrip patch antenna designed for IMT-2000 band is utilized to demonstrate the optimization technique. The data for curve fitting is obtained from Zealand IE3D software by varying different geometrical parameters of the antenna. Using the data, the equations representing the relationship among different parameters of a microstrip antenna are generated. Graphmatica curve fitting software was used to generate the curve. The PSO program was developed and executed in MATLAB and finally the optimized antenna was simulated in Zealand IE3D. Comparison between conventional antenna and curve fitting based PSO optimized antenna showed remarkable improvement over bandwidth. For the inverted E-shaped microstrip patch antenna, the bandwidth increased by 15%.

Optimization of microstrip patch antenna using Particle swarm optimization with curve fitting

In this paper, we propose to study the variability of speciflc absorption rate (SAR) of a human head due to difierent materials in the vicinity of the handset. We include the efiects of the human hand, handset chassis and additional conductive material particularly hand- ring jewelry. A flnite-difierence time-Domain (FDTD) method was used to analyze difierent positions of the conductive ring materials within the hand model. Furthermore, the impact of this material on the performance of an antenna was considered in this study. We found that including a hand model leads to a signiflcant reduction in SAR. The hand in∞uences not only SAR distribution but also antenna performance. Moreover, adding conductive materials to the hand results in increases in the local SAR values of the head model. The results suggest that the hand model is important in SAR evaluation and that having an additional conductive material on the hand may vary the amount of electromagnetic (EM) energy absorption depending on the position of the material.

/pdf/analysis-of-materials-effects-on-radio-frequency-41nv6swz0w.pdf

Analysis of Materials Effects on Radio Frequency Electromagnetic Fields in Human Head

A new design of dual band compact microstrip antenna is proposed for Ku-band applications. Dual band is achieved using three pairs of thin slits from the sides of a rectangular patch and feeding with a microstrip feedline. The antenna has a compact structure and the total size is 9.50 by 10 by 0.254 mm. The result shows that the return loss of-23.83 dB is achieved at the first resonant frequency of 12.54 GHz and-14.04 dB is obtained at the second resonant frequency of 14.15 GHz. The antenna gives a stable radiation performance with gain greater than 4 dBi over the frequency band.

Compact dual band microstrip antenna for Ku-band application

Supporting sensors integrated with IoT healthcare can effectively analyze and gather the patients' physical health data that has made the IoT healthcare ubiquitously acceptable. The continuous presence of the healthcare professionals and staff as well as the proper amenities in remote areas during emergency situations need to be addressed for developing a flexible IoT based health monitoring system. Development of IoT based health monitoring system allows a personalized treatment in certain circumstances that helps to reduce the healthcare cost and wastage with a continuous improving outcome. We present an IoT based health monitoring system using the MySignals development shield for Arduino Uno. Evaluating the performances and effectiveness of the sensors and wireless platform devices are also the aim of the project. MySignals enables multiple sensors such as temperature, ECG, oxygen saturation and pulse rate to gather the physical data. The aim is to transmit the gathered data from MySignals to a cloud or pc by implementing a wireless system with LoRa. The results show that MySignals is successfully interfaced with the ECG, temperature, oxygen saturation and pulse rate sensors. 36.5–37.5°C body temperature, 60–100 bpm pulse rate, and 96–99% oxygen saturation have been experimented with confidence interval approximation of 95%, 99% and 99%, respectively. The communication with the hyper-terminal program using LoRa has been implemented and an IoT based health monitoring system is being developed in MySignals platform with the expected results getting from the sensors.

Norbahiah Misran

Papers

Optimization of microstrip patch antenna using Particle swarm optimization with curve fitting

Analysis of Materials Effects on Radio Frequency Electromagnetic Fields in Human Head

Compact dual band microstrip antenna for Ku-band application

IoT Based Health Monitoring System with LoRa Communication Technology

Ionospheric and geomagnetic disturbances during the 2005 Sumatran earthquakes