Patent ID: 8907851
Filing Date: 2014-12-09
Classification: H01Q

Abstract:
1. A Planar antenna for use in a handheld device, the handheld device comprising a circuit board, the planar antenna comprising: a radiator comprising a feed point, a first short point and a second short point, the first short point being located in an end point of the radiator, the second shoring point being located in another end point of the radiator, and the feeding point being located between the first short point and the second short point; a feeding connector, being configured to couple the feeding point to the circuit board so that the handheld device transmits and receives a RF (radio frequency) signal through the radiator; a first short connector, being configured to couple the first short point to a ground of the circuit board so that the first short point is grounded; a control element comprising a first switch being coupled to the second short point; a second short connector, being configured to couple the first switch to the ground of the circuit board so that the second short point is grounded when the first switch turns on; and a third short connector; wherein the planar antenna operates at a first central frequency when the first switch turns off and operates at a second central frequency when the first switch turns on, and the second central frequency is different from the first central frequency; and wherein the radiator further comprises a third short point, the control element further comprises a second switch being coupled to the third short point, and the third short connector is configured to couple the second switch to the ground of the circuit board, wherein when the second switch turns on, the third short point is grounded so that the planar antenna operates at a third central frequency when both the first switch and the second switch turn on, and the third central frequency is different from the first central frequency and the second central frequency.