A Compact Internal Planar Antenna with a Capacitive Tuner for 3G and 4G Mobile Phone Application

A high performance planar antenna with a capacitive tuner as the radiator for 4G operation in the mobile phone is presented. A prototype of the proposed planar antenna with a compact area size of 60mmx13mmx5mm is implemented, and the antenna shows a wide operating bandwidth of about 295MHz and 490MHz for low band and high band bandwidth respectively, making it easy to cover the LTE, GSM, CDMA, and UMTS bands for wireless communication and make 3G/4G dual modes operation of a mobile handset phone. The study mainly focuses on the current trends in development of compact and low profile multi-media PDA and Smart mobile phone and provides a planar antenna design suitable for application in 4G wireless communicating systems in the future. The proposed antenna is easily fabricated by the flexible planar antenna at low cost and embedded into the mobile phone. A 50 ohms microstrip line is used to excite the planar antenna. The measured and simulated data including return loss, antenna gain and radiation patterns are presented.