Focal Region Ray Tracing of Conventional and Shaped Lens Antenna

Multibeam lens antennas are useful for 5G mobile communication systems. For multibeam design, feed position determination of specified lens becomes an important subject. The feed position data can be obtained from focal region ray tracing. In this paper, a simple and convenient ray tracing method by using the MATLAB function of “polyxpoly” is proposed. To evaluate the program, focal region ray tracing on conventional hyperbolic planar, spherical convex, and Abbe’s sine condition lens are presented in this paper. For focal region ray tracing, parallel incident ray is considered. The incident ray’s angle is changed from 0 degree to 30 degrees with an interval of 10 degrees. On hyperbolic planar and spherical convex lenses, ray concentration at the focal region is distorted at incident angle of 10 degrees and above. On Abbe’s sine condition lens, good concentration is maintained until 20 degrees. Concentration points agree well with the theoretical value. Therefore, the correctness of the program is ensured

Focal Region Ray Tracing of Conventional and Shaped Lens Antenna

Multibeam lens antennas are useful for 5G mobile communication systems. For multibeam design, feed position determination of specified lens becomes an important subject. The feed position data can be obtained from focal region ray tracing. In this paper, a simple and convenient ray tracing method by using the MATLAB function of “polyxpoly” is proposed. To evaluate the program, focal region ray tracing on conventional hyperbolic planar, spherical convex, and Abbe’s sine condition lens are presented in this paper. For focal region ray tracing, parallel incident ray is considered. The incident ray’s angle is changed from 0 degree to 30 degrees with an interval of 10 degrees. On hyperbolic planar and spherical convex lenses, ray concentration at the focal region is distorted at incident angle of 10 degrees and above. On Abbe’s sine condition lens, good concentration is maintained until 20 degrees. Concentration points agree well with the theoretical value. Therefore, the correctness of the program is ensured

Design of Normal Mode Helical Antenna for Seawater Application

To overcome the substantial propagation loss in the ocean, a low frequency band should be chosen when contemplating radio wave communication. Then, the antenna used at the portable radio equipment should be very small compare to the wavelength. For the miniaturized antenna, the normal mode helical antenna (NMHA) is suitable because of achieving high efficiency. In this paper, design method of NMHA in the seawater condition (r=81, =4) is explained. The frequency bands of 100MHz and 15MHz are selected. The self-resonant structures are determined based on the theoretical equation. Electrical characteristics such as resonant frequency, input impedance, VWSR and antenna efficiency are obtained through simulation by FEKO simulator. Electromagnetic simulation model is formed by taking into account the practical experimental condition. At 100MHz and 15MHz, resonances are ensured for antenna diameter lengths of 6.83 cm and 12.2 cm respectively. Input resistance of 27.15 and 94.14, antenna efficiencies of -14.88dB and -26.27dB are achieved at 100MHz and 15MHz respectively

Design of Normal Mode Helical Antenna for Seawater Application

To overcome the substantial propagation loss in the ocean, a low frequency band should be chosen when contemplating radio wave communication. Then, the antenna used at the portable radio equipment should be very small compare to the wavelength. For the miniaturized antenna, the normal mode helical antenna (NMHA) is suitable because of achieving high efficiency. In this paper, design method of NMHA in the seawater condition (r=81, =4) is explained. The frequency bands of 100MHz and 15MHz are selected. The self-resonant structures are determined based on the theoretical equation. Electrical characteristics such as resonant frequency, input impedance, VWSR and antenna efficiency are obtained through simulation by FEKO simulator. Electromagnetic simulation model is formed by taking into account the practical experimental condition. At 100MHz and 15MHz, resonances are ensured for antenna diameter lengths of 6.83 cm and 12.2 cm respectively. Input resistance of 27.15 and 94.14, antenna efficiencies of -14.88dB and -26.27dB are achieved at 100MHz and 15MHz respectively

Vertical and horizontal transmission enhancement between antennas using textile artificial magnetic conductor waveguide sheet

A textile artificial magnetic conductor (AMC) waveguide sheet with a textile diamond dipole is proposed to improve wireless on-body transmission. The sheet-like waveguide provides an independent transmission path which can reduce the performance degradation caused by the human body. The proposed AMC sheet is made entirely of textiles for both the substrate and the conducting parts, thus making it suitable for wearable communications. Transmission characteristics between antennas are studied rigorously in free space and on-body environments. Significant transmission enhancement is observed for all the tested orientations and positions for both free space and onbody placements. With the presence of the AMC, the S21 has peaks of up to a maximum of-9.9 dB. This textile AMC sheet constitutes a new approach for efficient wearable wireless body-centric communications

Fabrication of Human Body Phantom for Body Centric Communication Systems at 2.4 GHz

This research is intending to investigate the human skin phantom’s dielectric constant. The phantom will be used to test the electromagnetic compatibility later on since it can be harmful if it is directly tested on real human body. The human body phantom is made to have similar property as a skin tissue, at the operating frequency of 2.4 GHz. A methodology of the process is discussed. The phantom is fabricated, tested and measured. A fabricated phantom with the desired permittivity of εr and conductivity of σ values; are controlled by the amount of polyethylene powder and sodium chloride. The information on dielectric constant of the phantom based on measured values of εr and σ will be determined. The factors in making a good phantom is discussed. A good level of agreement is observed between simulation and measurement results

Band-pass Filter with Harmonics Suppression Capability

This paper presents a Band-pass Filter (BPF) with a very wide suppressions band. The filter design is based on a modified U-shaped slot. Two pair of U-shaped slots is used to ensure that the filter can suppress the unwanted frequencies up to 4th harmonics. In order to achieve sharp skirt, two transmission zeroes are created near the passband area. Additional transmission zeroes are introduced to deepen the stopband area. Therefore, the passband range starts from 1.3 to 3.3 GHz and the stopband range from 3.3 GHz up to 9 GHz are achieved. The filter performances are verified through simulated and measured results

Agricultural Production System Based On IOT

Internet of things (IoT) is not a single word, but it has gathered billions of devices in the same lane. The Internet of things has given the lives of things. Machines have a sense now like a human. It works remotely as the program has been settled inside the chip. The system has become so smart and reliable. The Internet of things has brought out changes in most of the sectors of humankind. Meanwhile, agriculture is the main strength of a country. The more the production of agricultural products increased, the world will be more completeness from food shortage. The production of agriculture can be increased when the IoT system can be entirely implemented in the agricultural sector. Most of the approaches for IoT based agriculture have been reviewed in this paper. Related to IoT based agriculture, most of the architecture and methodology have been interpreted and have been critically analyzed based on previous related work of the researchers. This paper will be able to provide a complete idea with the architecture and methodology in the field of IoT based agriculture. Moreover, the challenges for agricultural IoT are discussed with the methods provided by the researche

Docker containers usage in the internet of things: a survey

The Internet of Things (IoT) opened the way for enabling many of our everyday objects (things) interact with their environment to collect data, analyze and automating jobs based on specific rules. Within the constraint environment, the requirement of lightweight IoT application are tremendously indeed required to ensure the IoT application can be run efficiently. Docker containers is a promising technology to enable IoT application running smoothly, fast and efficient. In this paper, an introduction to Docker is presented. Then we explore the usage of Docker containers in the IoT application. Finally, we briefly discuss why Docker containers are usage in the IoT application

Wi-Fi Fingerprinting for Indoor Positioning

Wireless Fidelity (Wi-Fi) Fingerprinting is a remarkable approach developed by modern science to detect the user’s location efficiently. Today, the Global Positioning System (GPS) is used to keep track of our current location for outdoor positioning. In GPS technology, satellite signals cannot reach indoor environments as they are shielded from obstructions so that indoor environments with a lack of Line of Sight (LoS) do not provide enough satellite signal accuracy. Since indoor environments are very difficult to track, thus, a wide variety of techniques for dealing with them have been suggested. The best way to offer an indoor positioning service with the current technology is Wi-Fi since the most commercial infrastructure is well equipped with Wi-Fi routers. For indoor positioning systems (IPS), Wi-Fi fingerprinting approaches are being extremely popular. In this paper, all the approaches for Wi-Fi fingerprinting have been reviewed for indoor position localization. Related to Wi-Fi fingerprinting, most of the algorithms have been interpreted and the previous works of other researchers have been critically analyzed in this paper to get a clear view of the Wi-Fi fingerprinting process