A communication device (100, 400, 500), comprising: a ground element; and an antenna element, comprising: a first radiating portion, wherein one end of the first radiating portion is a feeding end of the antenna element, and the other end of the first radiating portion is an open end; and a second radiating portion, comprising a first portion and a second portion, wherein a first end of the second radiating portion, which is provided at the first portion thereof, is a shorted end coupled to the ground element, a second end of the second radiating portion, which is provided at the second portion thereof, is an open end, a length of the second radiating portion is greater than a length of the first radiating portion, and the second radiating portion surrounds the open end of the first radiating portion; characterized in that the communication device (100, 400, 500) further comprising a reconfigurable circuit element group (14, 44, 54), coupled between the first portion and the second portion of the second radiating portion, wherein the reconfigurable circuit element group (14, 44, 54) comprises at least two branches (141, 441, 541, 143, 443, 543) electrically coupling the first portion and the second portion of the second radiating portion, and the reconfigurable circuit element group (14, 44, 54) comprises at least one switch (144, 444, 544, 445, 545) for selectively opening and closing at least one of the branches (141, 441, 541, 143, 443, 543) such that the antenna element operates in different bands. a ground element; and an antenna element, comprising: a first radiating portion, wherein one end of the first radiating portion is a feeding end of the antenna element, and the other end of the first radiating portion is an open end; and a second radiating portion, comprising a first portion and a second portion, wherein a first end of the second radiating portion, which is provided at the first portion thereof, is a shorted end coupled to the ground element, a second end of the second radiating portion, which is provided at the second portion thereof, is an open end, a length of the second radiating portion is greater than a length of the first radiating portion, and the second radiating portion surrounds the open end of the first radiating portion; a first radiating portion, wherein one end of the first radiating portion is a feeding end of the antenna element, and the other end of the first radiating portion is an open end; and a second radiating portion, comprising a first portion and a second portion, wherein a first end of the second radiating portion, which is provided at the first portion thereof, is a shorted end coupled to the ground element, a second end of the second radiating portion, which is provided at the second portion thereof, is an open end, a length of the second radiating portion is greater than a length of the first radiating portion, and the second radiating portion surrounds the open end of the first radiating portion; characterized in that the communication device (100, 400, 500) further comprising a reconfigurable circuit element group (14, 44, 54), coupled between the first portion and the second portion of the second radiating portion, wherein the reconfigurable circuit element group (14, 44, 54) comprises at least two branches (141, 441, 541, 143, 443, 543) electrically coupling the first portion and the second portion of the second radiating portion, and the reconfigurable circuit element group (14, 44, 54) comprises at least one switch (144, 444, 544, 445, 545) for selectively opening and closing at least one of the branches (141, 441, 541, 143, 443, 543) such that the antenna element operates in different bands.