Effect of Textile Substrate on Antenna Performance for GPS Application

Wearable antennas made from textile materials for GPS (Global Positioning System) applications has been widely developed. However, textile materials have properties that can absorb water and be bent which will affect the performance of the antenna. Therefore, the testing of GPS antennas made from textile materials with five different substrates has been carried out to determine the effect of textile use on the antenna. Five substrate materials were felt, spun bond, cotton, drill, and denim. All antennas were designed to work on the GPS L1 frequency of 1,575 GHz with a value of S11 < −10 dB, bandwidth > 10 MHz, and axial ratio < 3 dB to achieve circular polarization. The study shows when affected by water absorption, there are 4 antennas that remain successfully work at GPS L1 frequency. When the antenna is tested in bending conditions, there are several antennas that can still work at GPS L1 frequency but are not stable for every bend condition.