A bandwidth-enhanced antenna in LDS technology for LTE700 and GSM850/900 standards

An antenna to cover the LTE700 and GSM850/900 frequency bands (i.e. 700-960MHz) for a typical handheld mobile communication device is presented. The design challenge is the relatively short system ground plane which is only 75mm long, relying only on the smartphone touchscreen as the ground plane. In order to obtain a high bandwidth potential with a single antenna feed, a grounded parasitic element is used in conjunction with the main excited strip. The antenna is manufactured using Laser Direct Structuring technology on a plastic piece. The connection between the antenna on plastic and the PCB is done thanks to two pogo-pins placed underneath the plastic piece. To tune the antenna to the desired frequency bands, a matching network consisting of only two lumped elements was manufactured on the PCB at the antenna feed. The target frequency band (i.e 700-960MHz) is covered with a reflection coefficient below -6dB both in simulations and measurements. The total efficiency of the antenna is measured to be higher than 45% on the whole bandwidth.