Folded Dual-Loop Antenna for GSM/DCS/PCS/UMTS Mobile Handset Applications

A folded dual-loop antenna suitable for GSM/DCS/ PCS/UMTS applications is proposed. It is fabricated using a pair of symmetric meander strips to form two loops. By properly bending the radiating strips, the antenna can achieve a compact size of 50 (L) × 9 (W) × 9 (H) mm³ to be integrated within a mobile handset device as an internal antenna. With 6 dB return loss, two operating frequency bands covering 847-971 and 1670-2230 MHz can be obtained with our design. Moreover, the resonant characteristics of the antenna can be tuned by using various strip lengths and also spaces between the radiator and the ground plane. Experimental results exhibit that the proposed folded dual-loop antenna features nearly good omnidirectional radiation patterns with proper gain, so it is well suitable to meet GSM/DCS/PCS/UMTS operations for mobile handset applications.