Low-profile capacitive fed air-supported microstrip antenna at UHF band for biomedical application

A compact L-shaped strip fed air-supported microstrip antenna with a simple structure is proposed at UHF band. This linear polarized microstrip antenna (LPMA) is miniaturized by bending both opposite sides of the antenna. To achieve the low profile, the L-shaped feeder, compensating the reactive of the antenna, has been designed. The dimensions of the proposed antenna are 200 mm×200 mm×15 mm (0.27λ₀× 0.27λ₀ ×0.026λ₀) at the center frequency 417 MHz). The antenna has been successfully simulated, fabricated and measured. Experimental results show that the proposed antenna exhibits a good impedance bandwidth of 7 MHz (414 MHz-421 MHz) for VSWR <; 2. The simulation and measured results show a good agreement with each other.