Design & Development of Wearable Device for Wireless Communication System

Wireless networking has become an integral part of contemporary life, and it is expected to become much more so in the future. As a result, integrating lightweight fabric antennas may have a variety of applications. Wireless networking is becoming an increasingly important aspect of everyday life, and it is only likely to grow in importance in the future. At microwave wavelengths, the human body has a high dielectric constant and poor conductivity. These material characteristics may have a direct, and perhaps detrimental, impact on the gain and radiation efficiency of an antenna placed on or within the human body. When an antenna utilizes a zener diode to operate on or near the human body, the Specific Absorption Rate (SAR) is an essential issue for measurement. To protect the human body from radio wave radiation, WBAN antennas must have a low specific absorption rate that varies based on the diode states of ON and OFF in the Zener diode. Wearable communication systems need a compact transmitter with low power consumption and optimal signal transmission to the human body. The H-shaped antenna is constructed using the transmitting model. The capacitive range between 3.85pF and 1.88pF, as well as the zener diode, are used to change different frequencies. The antenna is constructed on an 80mmX60mm dielectric substrate made of FR4 epoxy, with a switch size of 0.7mm X1.4mm and a relative permittivity of 3.68, and a substratum height of 1.6mm. A 50ohm matching impedance coaxial cable provides power to the proposed structure's patch. To control a particular switching mechanism, dynamic tuning may be achieved by manipulating electrical, mechanical, physical, or optical switches. Electronic switches are the most often utilized in the building of reconfigurable antennas due to their efficiency, longevity, and ease of integration with microwave electronics.
Single antennas that work at different frequencies are becoming outdated as wireless technology develops, according to a new study. The microstrip patch antenna, the most popular printed type antenna, is suitable for a
broad variety of applications. To build up the antenna design, Zener diodes are placed in different locations on the patch. Depending on the Zener diode's switching state, the antenna may operate in a number of frequency bands. The frequency range obtained is 2.5GHz to 9.5GHz. The obtained VSWR (Voltage Standing Wave Ratio) is excellent. A tiny frequency reconfigurable H-shaped slot antenna is suggested for wireless communication. The proposed antenna uses a double slot with zener diodes positioned at different points on the ground plane to provide frequency reconfigurability. Depending on the zener diodes switching state, the antenna may function in a variety of frequency bands. The antenna's radiation pattern is nearly omnidirectional across all frequency bands. The simulated reflection coefficient is equal to the optimum value for all frequency bands. VSWR, reflection coefficient, and radiation pattern are all simulated antenna properties.
In terms of VSWR, Return Loss, Directivity, and Cross-Polarization, the proposed antenna works well. The bandwidth is greatly increased by adding two slots on both the left and right sides of the H-shape. When the D1 & D2- ON, D1 & D2-OFF, and D1-ON&D2-OFF bands are used, the proposed antenna operates at 2.5GHz to 9.5GHz and 2.2GHz to 4.8GHz when the D1 & D2-ON, D1&D2-OFF and D1-OFF & D2-ON bands are used, respectively. The gain is greater than 8.2dB and lower than 3.2dB, the reflection coefficient is maximum - 32.68dB and lowest is -15.68dB, the VSWR is maximum 1.9 and minimum value is 1.1, and efficiency is maximum 85 percent and minimum 80 percent.