A Comparative Study of Simulation Methods for Patch Antenna Strain Sensors

Passive wireless strain sensors based on microstrip patch antennas recently show significant promise for reliable health and performance monitoring in the aerospace and civil industries. Microstrip patch antenna consists of a metal patch, dielectric substrate, and metal grounding plate. When excited by the signal, an electro-magnetic resonant cavity is formed between the conductor patch and the grounding plate and radiates outward through the gap between the patch and the grounding plate. These antennas radiate at their resonant frequency. When the antenna experiences deformation, the antenna shape changes, causing a shift in the electromagnetic resonance frequency of the antenna. For this purpose, the antenna design is critical to influencing both RF characteristics and strain sensing behavior. In this work, a passive wireless strain sensor using a microstrip patch antenna with feed-inset operating at 2.8 GHz was designed and simulated in different simulation methods using simulation software CST Microwave studio and COMSOL Multiphysics. The simulation results were compared regarding the patch antenna's processing time, linearity, and sensitivity for strain sensing. Among these methods, strain and RF simulation of patch antenna using COMSOL software show better accuracy and linear response towards strain.