Tuning of LTE main antenna using flexible tunable LC resonant circuitry

There have been an increasing trend in using metallic housing for mobile phone. The metallic housing can comes in many different forms ranging from a metal frame/rim that goes around the side of the mobile phone; to metal frame/rim with slots cut on it; to a full metallic back cover covering the back and side of the mobile phone. These metallic housing improves the outlook appearance of the mobile, and adds mechanical strength for the mobile phone. However, from the antenna point of view, such metallic housing often posts a great challenge towards the flexibility in designing the antenna and reduces the antenna sensitivity performance. This paper presents approaches of overcoming the challenges by introducing Tunable Circuitry that can be applied on both Aperture Tuning and Impedance Matching of the antenna in mobile phone with metallic back cover.