Broadband variable antenna device and portable terminal having the same

摘要

Disclosed is an antenna device for a portable terminal, including a circuit board having a conductive layer attached on a surface, a first slit formed by partially removing the conductive layer in a position adjacent to one side of the circuit board, the first slit extending in parallel with a lateral periphery of the circuit board, a radiation portion comprising part of the conductive layer positioned on the lateral periphery of the circuit board in one side of the first slit, and a feed line placed on the first slit and adapted to feed the radiation portion from the other side of the first slit. The radiation portion further comprises a second slit extending from the first slit to the lateral periphery of the circuit board across part of the conductive layer forming the radiation portion, and a frequency adjustment element placed on the second slit.

主权项

1. An antenna device for a portable terminal, comprising:
a circuit board having a conductive layer formed on a surface; a first slit formed by partially removing the conductive layer in a position adjacent to one side of the circuit board, the first slit extending in parallel with a lateral periphery of the circuit board; a radiation portion comprising a part of the conductive layer positioned on the lateral periphery of the circuit board in one side of the first slit; and a feed line that is placed in the first slit and is configured to couple the radiation portion from another side of the first slit; a second slit extending from the first slit to the lateral periphery of the circuit board across a part of the conductive layer forming the radiation portion; a frequency adjustment element that is placed on the second slit and is configured to connect in series portions of the conductive layer divided by the second slit and positioned in both sides of the second slit; and an auxiliary board that has a radiation pattern thereon, and is mounted over the circuit board, wherein the radiation pattern is electronically connected to a portion of the conductive layer, and is extended to partially surround the first slit when seen in a top view, wherein when a transmission signal applied to the feed line, the antenna device generates a current flow around the first slit in a direction following a signal power, which flows through the radiation pattern such that the antenna device prevents an inverse current with respect to the signal power from being induced around the first slit.