Low-Profile Microstrip Patch Antenna for Over-Body Surface Communication at 2.45 GHz

A compact higher-order mode microstrip patch antenna (HM-MPA) suitable for on-body communications at 2.45 GHz is presented. Using FDTD simulations we show that the HM-MPA had an impedance bandwidth of 150 MHz and a relatively good bodyworn efficiency of more than 60% when placed in close proximity from a lossy medium with the characteristics of muscle tissue. On-body performance was investigated by modelling S₂₁ coupling of two HM-MPAs spaced 200 mm apart on a muscle tissue layer. The HM-MPA coupling results are comparable to those achieved using a quarter wave monopole antenna on the same size of groundplane, mounted normal to the tissue surface. Considering that the HM-MPA has the benefit of being low-profile and physically more robust, it is a promising solution for over body surface applications.