TITLE:
New Wideband Compact Wearable Slot Antennas for Medical and Sport Sensors
AUTHORS:
Albert Sabban
KEYWORDS:
Wearable Sensors, Medical Applications, Active Systems, Medical and Sport Sensors
JOURNAL NAME:
Journal of Sensor Technology,
Vol.8 No.1,
March
22,
2018
ABSTRACT: Communication, Biomedical and sports industry is in continuous growth in the last decade. Wide band compact wearable active and tunable sensors and antennas are crucial in development of new wearable Body Area Network, BAN, systems. BAN antennas should be flexible, light weight, compact and have low production cost. Slot antennas are compact and have low production costs. Slot antennas may be employed in wearable communication systems. The dynamic range and the efficiency of communication systems may be improved by using efficient wearable slot antennas. Small printed antennas suffer from low efficiency. Amplifiers may be connected to the wearable antenna feed line to increase the system dynamic range. Novel wideband passive and active efficient wearable antennas for BAN applications are presented in this paper. Active wearable antennas may be used in receiving or transmitting communication and medical systems. The slot antenna bandwidth is from 45% to 100% with VSWR better than 3:1. The slot antenna gain is around 3 dBi with efficiency from 85% to 92%. The antenna electrical parameters were computed in vicinity of the human body. The active slot antenna gain is 18 ± 2.5 dB for frequencies ranging from 200 MHz to 750 MHz. The active slot antenna gain is 12 ± 2 dB for frequencies ranging from 1.3 GHz to 3.3 GHz. The active slot antenna Noise Figure is 0.5 ± 0.3 dB for frequencies ranging from 200 MHz to 3.3 GHz. A voltage controlled diode, varactor, may be used to control the antenna electrical performance at different environments. For example an antenna located on the patient stomach has VSWR better than 2:1 at 434 MHz. However, if the antenna will be placed on the patient back it may resonate at 420 MHz. By varying the varactor bias voltage, the antenna resonant frequency may be shifted from 420 MHz to 434 MHz. The antennas presented in this paper are low cost wideband active antennas for receiving and transmitting communication systems.