Patent ID: 6653978
Filing Date: 2003-11-25
Classification: H01Q,H05K

Abstract:
A method of achieving a right-handed circular or elliptical polarization field in a mobile terminal having a body radiation mode, said mobile terminal comprising a radio-frequency antenna, and a chassis or circuit board for mounting the radio-frequency antenna, the chassis or circuit board having four corners to define a plane having a first axis and a second axis perpendicular to the first axis, wherein the radio-frequency antenna comprises:a radiator part; and a support frame for effecting dielectric loading on the radiator part, wherein the radiator part comprises: a resonating region for transmitting and receiving signals in a radio frequency range; a feeding region coupled to the resonating region for impedance matching, and an electrically grounding end located in the proximity of the feeding region, and wherein the radiator part has a first radiation mode and a second different radiation mode, said method characterized bydisposing the radio-frequency antenna at one of the corners of the chassis or circuit board such that the first radiation mode propagates along the first axis and the second radiation mode propagates along the second axis, the first and second radiation modes forming an antenna radiation mode orthogonal to the body radiation mode the method being further characterized by providing a slit formed between corners of the chassis or circuit board, to tune the body radiation mode, for optimizing the right-hand circular or elliptical polarization field.