A bandwidth-enhanced low-profile antenna for in-machine wireless harness communications and its clearance distance evaluation

This paper develops a bandwidth-enhanced low-profile antenna suitable for a new emerging in-machine wireless communication used in a metal-rich confined volume. In the developed antenna, the combination of a slotted ground plane and a feeding patch realizes dual resonances for bandwidth enhancement. It also provides the stability of the reflection characteristic when the antenna is placed very close to metallic obstacles, without using any additional matching networks. The reduction of clearance distance, which is defined by a minimum antenna-metal distance, is confirmed by the comparison with a conventional low-profile inverted-F antenna.