Spiral-shaped printed planar inverted-F antenna for body wearable application

This paper presents a spiral-shaped printed planar inverted-F antenna (PIFA) for body wearable application. A combination method between planar inverted-F technique and geometry modification is implemented for reducing the physical dimension of proposed antenna. The antenna which is intended to work at the frequency of 920MHz is designed and implemented using a circular shape of FR4 epoxy dielectric substrate with the thickness and diameter of 0.8mm and 18mm, respectively. Prior hardware realization, the parameters of antenna such as reflection coefficient, working bandwidth, gain, and radiation pattern are numerically investigated to achieve the design with optimum performance. Meanwhile from the characterization, the measurement result indicates that the realized antenna has the resonant frequency of 911MHz with -10dB measured working bandwidth of 20MHz and gain of -30.79dBi. This achievement could be beneficial for body wearable application such as implantable antenna.