QUAD-BAND INTERNAL ANTENNA AND MOBILE COMMUNICATION TERMINAL THEREOF

摘要

Disclosed are a quad-band internal antenna and a mobile communication terminal thereof. The internal antenna comprises an antenna radiating element, and arranged on a printed circuit board a first slotted hole and a second slotted hole. The first slotted hole is arranged along the direction perpendicular to the flow of current of the printed circuit board. The second slotted hole is arranged between a ground pin and a feed pin of the antenna radiating element. The first slotted hole and the second slotted hole are both open slotted holes. As the addition of the slotted holes is employed on the printed circuit board to adjust a low-frequency resonance mode thereof, the low-frequency bandwidth of the antenna is expanded. The high-frequency bandwidth is expanded by exciting a quarter wavelength resonance mode of the first slotted hole to be used as a high-frequency parasitic resonant element. As the second slotted hole exerts effects of matching and fine tuning on an input impedance of the low and high frequencies, a frequency shift caused by the terminal being held in a user's hand is compensated, and the characteristic of the mobile communication terminal when operating in a hand-held mode is optimized. A characteristic of relatively expansive bandwidth is allowed in a limited space, and the needs of mobile communication terminal miniaturization development are thereby met.