Loop antenna for cell phone having a metallic or non-metallic casing

• US 20100087235A1
• Filed: 10/08/2008
• Published: 04/08/2010
• Est. Priority Date: 10/08/2008
• Status: Abandoned Application

• Current Assignee: Auden Techno Corp.
• Original Assignee: Auden Techno Corp.
• Inventors: Chiang, Chi-Ming
• Application Number:
  US12/285,539
• Publication Number:
  US 20100087235A1
• Time in Patent Office: Days
• US Class Current: 455/575.700
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop

Abstract

A loop antenna used in a cell phone having a circuit board and a casing housing the circuit board is disclosed to include a loop extending around the border of the circuit board, a ground end extending from one end of the loop and electrically connected to a ground plane of the circuit board, a feed end extending from the opposite end of the loop and electrically connected to the circuit board for signal input, and two cut-off ends formed in a middle part of the loop to cut off the loop. The two cut-off ends are electrically connected to the casing of the cell phone if the casing is a metallic casing, or short-circuited if the casing of the cell phone is a non-metallic casing.

Claims

1. A loop antenna installed in a cell phone comprising a casing and a circuit board mounted in said casing, the loop antenna comprising:

a loop extending around the border of said circuit board;

a ground end extending from one end of said loop and electrically connected to a ground plane of said circuit board;

a feed end extending from an opposite end of said loop and electrically connected to said circuit board for signal input; and

two cut-off ends formed in a middle part of said loop to cut off said loop;

wherein said two cut-off ends are electrically connected to the casing of said cell phone when the casing of said cell phone is a metallic casing;

said two cut-off ends are short-circuited when the casing of said cell phone is a non-metallic casing.

2. The loop antenna as claimed in claim 1, wherein said loop, said ground end and said feed end are formed integrally in said circuit board by an etching technique.

3. The loop antenna as claimed in claim 1, wherein said loop, said ground end and said feed end are formed in integrity beyond said circuit board and then installed in said circuit board.