Communication device with narrow-ground-clearance antenna element

A communication device, the communication device comprising a system circuit board and an antenna element, the system circuit board having a ground plane, the antenna element comprising a radiation metal strip, the radiation metal strip and the system circuit board not lying on a same surface, the radiation metal strip being extended along a first edge of the system circuit board, the radiation metal strip and the ground plane being separated by a clearance region, the clearance region having a width, the ground plane not being disposed in the clearance region, the radiation metal strip having a first end and a second end, a distance between the first end and the second end is a length of the radiation metal strip, the radiation metal strip comprising:

• a first metal strip, having the first end, wherein the first end is electrically connected to the ground plane by a first inductive element;
• a second metal strip, having the second end, wherein the second end is electrically connected to the ground plane by a second inductive element;
• and
• a coupling metal strip, located between the first metal strip and the second metal strip, and located on a same plane with the first metal strip and the second metal strip, a first gap being located between the coupling metal strip and the first metal strip, a second gap being located between the coupling metal strip and the second metal strip, the coupling metal strip having an antenna feed point, the antenna feed point being electrically connected to a signal source located on the system circuit board by a feed metal line, wherein a distance between the first gap and the antenna feed point is not greater than the width of the clearance region, a distance between the second gap and the antenna feed point is also not greater than the width of the clearance region, and the width of the clearance region is from 0.5 mm to 4.0 mm.