Planar antenna for a cellular phone

Abstract

The continued size reduction of cellular phones, especially reduction their thickness leads to challenges for phone and antenna designers. Efficient antenna solutions that cover all needed bands are required no matter what volume has been allocated for the antenna. The optimal solution regarding antenna thickness will be achieved when the antenna is integrated into the PCB of the device. A particularly difficult challenge is to ensure that the antenna performs well in all user positions. A slim phone design tends to bring the antenna even closer to the users body, which is the main source of RF energy loss; leading to higher body loss and lower efficiency in use. This requires careful placement of the antenna element on the PCB within the device to ensure minimal user body effect. The market offers cellular phones varying from the ultra low cost versions to feature rich smart phones. Cost of the components including the antenna is the most critical parameter in the low end segment while number of bands and performance are the driving factors in the high end. This paper provides a solution for a multi-band antenna that can be fully integrated on the PCB of the device.