A COUPLED-FED LOOP ANTENNA FOR FOURTH GENERATION MOBILE SYSTEM APPLICATIONS

摘要

This article proposes a compact printed meander loop antenna for the fourth generation (4G) mobile system applications. The total length of the meander loop operates a one-wavelength resonant mode (mode 1) at 774 MHz. To increase the antenna's operation bandwidth, this article uses coupled-fed feeding method that contains a coupling patch connected with a 50-Ω microstrip feed line. By applying the coupled-fed method, a new one-wavelength resonant mode (mode 2) is excited. After carefully adjusted the size of coupling patch, the frequency of mode 2 shifts to 904 MHz combining with mode 1 to form dual broad operations bands. The measured dual broad bands from 658 to 963 MHz and from 1658 to 2693 MHz can be applied in the 4G mobile system, especially for the long-term evolution application. The two resonant modes are resonated by 1λ loop type that has less influence by changing the size of ground plane. The antenna portion and overall dimensions of the proposed antenna are 20×60×0.8 mm~3 and 120×60×0.8 mm~3 suitable for today's mobile phone application. With the advantages of board band, compact size, low cost, and good performance, the proposed antenna appears to be a promising candidate for the 4G mobile applications.