Coupled retractable whip/stub antennas for mobile phones

In this paper, a whip/stub antenna design is presented that utilizes an additional matching circuit to manipulate the coupling between the whip and stub in order to provide higher design flexibility. The flexibility of this antenna makes it suitable for use in mobile phones with variable form configurations, such as fold or slide phones. A methodology on how to select the whip length and the radiator structure of the stub antenna is described.