Abstract: An external antenna detection apparatus in a mobile terminal for receiving a satellite digital multimedia broadcasting (DMB) service. The external antenna detection apparatus includes at least one built-in antenna for receiving a gap filler signal; a detachable external antenna for receiving a satellite signal; a radio frequency (RF) module for transmitting/receiving a radio signal; an antenna connector for switching a reception path to one of a first path connected to the built-in antenna and a second path connected to the external antenna; a connector coupler for selecting the reception path according to whether the connector coupler is coupled to the antenna connector; and a baseband processor for processing a signal received through the first or second path via the RF module, monitoring a change in voltage-level signal, and detecting attachment and detachment of the external antenna according to the monitoring result.