A Microstrip Patch Antenna Immersed in Water – A Preliminary Investigation

Microstrip patch antennas (MPAs) are versatile in their utility and they are frequently used as sensors for permittivity measurements. This short paper is focused on a rectangular configuration designed to resonate at 2.5 GHz. The performance of the antenna is analysed while it is radiating both in air and in water. This is required in order to assess the feasibility of using the antenna as a sensor for permittivity measurements in water. Analytical equations for designing the rectangular patch are used in combination with several simulations using CST Studio Suite in order to optimise the antenna through a trial and error procedure. A significant decrease in the magnitude of the resonant peak of the antenna and an increase in the quality factor is observed as the volume of water above the antenna is increased.