Dual-Band Slot Antenna with Metal Surroundings for WBAN Applications

Abstract

A dual-band slot antenna with metal back-cover and metal rim for WBAN applications is proposed. A T-shaped coupled feed structure on FR4 substrate is placed under the metal back-cover and surrounded by an unbroken metal rim. A slot antenna operating at 2.45 GHz is designed first on the metal back-cover and two parasitic elements nearby the feed structure are added to enhance the bandwidth in 2.45 GHz ISM band by exciting TM11 mode on the ground plane. Another parasitic element nearby the feed structure is used to cover 5.8 GHz ISM band. Then, additional two shorting strips between the metal back-cover and the surrounding metal rim are applied to control current flows properly in 2.45 GHz and 5.8 GHz ISM bands. The proposed antenna satisfies required bandwidths in 2.45 GHz and 5.8 GHz ISM bands. In addition, the radiation pattern of the proposed antenna is outward directional on the human equivalent flat body phantom, which is desirable for WBAN applications.