Patent ID: 6239755
Filing Date: 2001-05-29
Classification: H01Q

Abstract:
A balanced, retractable dipole antenna for use in a mobile phone having a casing, and a signal source, transmit and receive circuits, and a printed wire board (PWB) having a ground plane formed thereon for the signal source and for the transmit and receive circuits contained in the casing, comprising:a first radiator element formed of a conducting material and being selectively extendable from and retractable into the casing;a second radiator element formed of a conducting material;a counterpoise formed of a conducting material and electrically isolated from the PWB ground plane;a signal balancing means coupled between the signal source and at least said second radiator element and counterpoise to generate first and second signals, respectively, wherein said first and second signals are substantially equal in magnitude but out of phase by 180 degrees;means for transferring said first signal to said second radiator element;means for transferring said second signal to said counterpoise;means for transferring said first signal to said first radiator element when said first radiator element is extended; andmeans for transferring said second signal to said first radiator element when said first radiator element is retracted.