Analyzing Microstrip Antenna Miniaturization Methods for Wearable IoT Sensors

This paper analyzes the advantages and disadvantages of several methods for miniaturizing microstrip patch antennas. There are some ways to reduce the size of a microstrip antenna, including using a high relative permittivity (ε<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</inf>), attaching shorting pins, modifying the patch, adding slots, and using metamaterial. To fairly compare these methods, the simulation results of each method in terms of S-parameters, realized gain, and efficiency at a single frequency band of 2.45 GHz are detailed. Based on the analyzed simulation results, some miniaturization methods for wearable IoT sensors are recommended, and a miniaturized antenna with a small size but remains 10% higher efficiency and 1.5 dBi higher gain is proposed compared to the original square microstrip patch antenna.