Handheld device and planar antenna thereof

摘要

A handheld device and a planar antenna thereof are provided. The planar antenna comprises a radiator, a screening element and a switch. The screening element is configured to make the planar antenna operating in a first high-frequency (HF ) current path and a first low-frequency (LF) current path, and the switch is configured to make the planar antenna operating in a second HF current path and a second LF current path. The planar antenna operates at a first HF central frequency corresponding to the first HF current path and a first LF central frequency corresponding to the first LF current path when the switch is turned off, and operates at a second HF central frequency corresponding to the second HF current path and a second LF central frequency corresponding to the second LF current path when the switch is turned on.