A PRINTED COUPLED-FED LOOP ANTENNA WITH TWO CHIP INDUCTORS FOR THE 4G MOBILE APPLICATIONS

摘要

This article proposes a meandered printed loop antenna for the fourth generation (4G) mobile system applications. Using a coupling strip connected with a 50Ω microstrip fed-line on front side, the loop antenna on back side is excited and a half wavelength (0.5 k) resonant mode and its higher modes are successfully resonated. A plane copper strip connected at top of the loop antenna is used to increase the antenna's path and to decrease the lower operation band to cover LTE 700 band. Two 15 nH ceramic chip inductors, which are embedded in the loop antenna, are used to decrease the antenna's 1 and 1.5 λ resonant modes. The 0.5, 1, and 1.5 k resonant modes get together to form a broad lower operation band (693-1031 MHz) for LTE 700 and GSM 850/900 applications. Beside, the antenna's higher resonant modes are also excited to form a broad higher operation band (1668-2781 MHz) for DCS, PCS, UMTS, LTE 2300, LTE 2500, and WLAN applications. The proposed antenna also has an advantage of small size, which is 114×50 mm~2 including a loop antenna of 14×50 mm~2 and a ground plane of 100×50 mm~2. With the advantages of board band, compact size, low cost, and good performance, the proposed antenna appears to be an optimal candidate for the 4G mobile applications.