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

Simulation of WCDMA radio over fiber technology

The demand for broadband services has driven research on millimetre wave frequency band communications for wireless access network due to its spectrum availability, and compact size of radio frequency devices. However, the mm-wave signals suffer from severe loss along the transmission as well as atmospheric attenuation. In other words, upcoming wireless networks will use a combination of airinterface methods in different channels and in different cells that can be changed dynamically to meet variations in traffic conditions. One of the solution to overcome these problem is by using low-attenuation, electromagnetic interference-free optical fiber. Radio over Fiber (RoF) is integration of optical fiber for radio signal transmission within network infrastructures that is considered to be cost-effective, practical and relatively flexible system configuration for long-haul transport of millimetric frequency band wireless signals. This project is about to simulate WCDMA Radio Over Fiber using Matlab Simulink. By doing so, the efficiency can be measured by the performance of BER (Bit Error Rate). The finding of this project is the WCDMA RoF is suite with 3G and 4G application along with increasing users every year whole the world. The conclusion is the simulation of WCDMA RoF was success developed throughout objective

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