Reconfigurable LTE/WWAN antenna design

A low-profile, small-size (10 × 40 mm2 on a thin dielectric substrate) planar LTE/WWAN antenna suitable for slim laptop computer applications is presented. The antenna is formed by a coupled-fed loop and a reconfigurable circuit element. The reconfigurable circuit element is substantially positioned at the current nulls of the two higher-order resonant modes of the coupled-fed loop, thereby altering the frequency of the lowest resonant mode of the coupled-fed loop without affecting the higher-order resonant modes. By switching the reconfigurable circuit element, the resonant path of the coupledfed loop is altered without changing the size of the antenna configuration, and the obtained resonant modes of the antenna can cover the LTE/WWAN bands. Good radiation characteristics of the antenna in the low-band and high-band operations are also obtained. Details of the proposed antenna and its experimental and simulated results are presented.