Abstract: An antenna arrangement including a first element operable in a first resonant mode at a first resonant frequency band; and a second element arranged to couple with the first element to enable the first element to resonate in a second resonant mode having a second resonant frequency band, the second element having an impedance at the first resonant frequency band which substantially suppresses coupling between the first element and the second element.

Abstract: A directional antenna and a portable electronic device using the same are provided. The directional antenna includes L-shaped radiator, L-shaped oscillator, and L-shaped reflector and it is preferred that the directional antenna is positioned at corners of the substrate. The L-shaped radiator is made resonant by the L-shaped oscillator and has higher gain to maximize performance of signal transmission. The directional antenna achieves signal transmission in a specific direction over a long distance by the L-shaped reflector. In addition, with the gravity sensor, the processor and the switches, the directional antenna is automatically adjusted to a predetermined direction to transmit and receive signals even through orientation of the electronic device is changing at any time.