Electrically Controlling the Chassis Via A Notching Approach for Improved Handset Performance

We present in this paper an approach to control the chassis through electrically extending the length of the ground plane. With this, improved antenna performance in the handset is achieved. The electrical lengthening is made through a nothing approach to the ground plane longitudinal edges. The notches are carefully designed such that they do not interact with the antenna deteriorating its characteristics or radiate causing interference issues. We show the proposed approach through implementation on an internal hexa-band antenna. The improved antenna performance is measured through its bandwidth and efficiency. The performance is examined at two frequencies, 900 MHz and 1880 MHz. An improvement of 22% in the bandwidth at 900 MHz and a 2% improvement at the higher 1880 MHz band are achieved with a similar or a slight improvement in antenna efficiency. The proposed approach is flexible and practical in its implementation and can easily be implemented in the handset to improve the antenna performance, thus, no need to physically enlarge the handset ground plane.