This thesis presents a study on built-in type low profile and low volume mobile phone antennas. In a coupling element based antenna, the chassis is the main radiator and the antenna elements are the exciters for the wave modes at low frequency. The main work of this thesis is to demonstrate and investigate the performance of the coupling element based antenna and study a variety of cases with different physical lengths and different physical heights. The investigation is done by using simulators. The performance is evaluated by analyzing the impedance bandwidth and the efficiency. For the study, antenna prototypes integrating miniaturized matching circuits were modeled. Two antenna structure prototypes were manufactured and measured. The Measured results are presented and compared with simulations. Finally, the performance of the coupling element based antenna is compared with planar inverter-F antenna (PIFA) and discussed.