Performance Analysis of a Monopole Antenna with Fluorescent Tubes at 4.9GHz Application.

This paper presents of analysis the performance monopole antenna with fluorescent tubes. The antenna was designed at the operating frequency which is 4.9 GHz. The commercially fluorescent tubes consist of a glass tube filled with mixture mercury vapor and argon gas. After get sufficient voltage the gas inside the fluorescent tube will ionize to plasma and formed plasma column. The plasma frequency is equal to 5.634e11 Hz. The plasma is highly conducting and acts as a reflector. When all of the tubes surrounding the antenna are electrified, the radiation is trapped inside when the plasma frequency is greater than radio frequency. An accomplishment of the design has been carried out using CST microwave studio software. The developed antenna has potential in military application. To conclude, antenna’s performance was analyzed in terms of return loss, radiation pattern and gain. Keywords : Plasma, monopole antenna, return loss, radiation pattern, gain

Design of an axial mode helical antenna with buffer layer for underwater applications

Recently, there is an increasing demand for high-speed wireless communication network for short-range underwater communication. From previous research, most underwater antennas produced omnidirectional radiation pattern which has lower antenna gain. There are a few considerations that need to be taken if the antenna is designed to operate in water environment. This paper discusses the electromagnetic properties which affect the underwater antenna design. Physical properties such as electrical permittivity and conductivity of water contribute significant effect to the size of the antenna as it influences the behavior of electromagnetic signal that propagates in water. In this study, an axial mode helical antenna with waterproof container is presented which operates at 433 MHz. The axial mode helical antenna has circular polarization and is suitable to support wireless application which is surrounded by some obstruction. The proposed antenna produces a bidirectional radiation pattern by placing it into a waterproof casing. Good agreement between the simulation and measurement results validates the concept. However, a little discrepancy between the simulated and measured results may be attributed to the noise originated from the equipment and the environment

Overview of underwater communication technology

Wireless transmission is important either in normal terrestrials or underwater network. It provides connection regardless of the obstacle surrounding the network. This technology can contribute to various benefits in terms of underwater environmental monitoring, oil and gas exploration, surveillance operation and military. In water environment, there are three common techniques that are normally available nowadays which rely on acoustic, optical or radio frequency (RF) channel. Acoustic is the earliest underwater communication technology which is widely used and it allows the longest range of communication, but it has some limitations in term of the low throughput and is also affected with the Doppler effects. Optical and RF technology are able to provide higher data rate compared to acoustic but both technologies have limitation in term of the transmission distance. However, RF technology is more suitable to be considered for short distance transmission with moderate data rate as the optical signal normally requires line-of-sight between transmitter and receiver link that is hard to be achieved in water that has higher particle inside. Therefore, suitable antenna design should be created to establish underwater communication that employs RF technology that can transmit higher data rate in short distance

A review on internet of things-based stingless bee's honey production with image detection framework

Honey is produced exclusively by honeybees and stingless bees which both are well adapted to tropical and subtropical regions such as Malaysia. Stingless bees are known for producing small amounts of honey and are known for having a unique flavor profile. Problem identified that many stingless bees collapsed due to weather, temperature and environment. It is critical to understand the relationship between the production of stingless bee honey and environmental conditions to improve honey production. Thus, this paper presents a review on stingless bee's honey production and prediction modeling. About 54 previous research has been analyzed and compared in identifying the research gaps. A framework on modeling the prediction of stingless bee honey is derived. The result presents the comparison and analysis on the internet of things (IoT) monitoring systems, honey production estimation, convolution neural networks (CNNs), and automatic identification methods on bee species. It is identified based on image detection method the top best three efficiency presents CNN is at 98.67%, densely connected convolutional networks with YOLO v3 is 97.7%, and DenseNet201 convolutional networks 99.81%. This study is significant to assist the researcher in developing a model for predicting stingless honey produced by bee's output, which is important for a stable economy and food security

Antenna and radio propagation analysis in several dielectric materials by em simulator

Recently, radio wave technologies are applying for human health care such as a capsule endoscopy and a hyperthermia. As another application, radio wave is planning to be used in seawater radio communication. At human body and seawater applications, a small size antenna is suitable. So, the normal mode helical antenna (NMHA) that has high efficiency at small size is selected. As for performance understanding, electromagnetic simulation tool is effective. The important subject in antenna application is to clarify the radio wave communication link budget in the dielectric material environment. In this paper, based on electromagnetic simulation results of antenna and radio propagation in the human body and seawater conditions, analytical understanding of antenna performance and radio propagation mechanism is conducted. Through this study, analytical equations for antenna performance and radio wave propagation are derived. The effectiveness of derived equations are ensured through comparison with simulation results