The device includes radio frequency (RF) communication components installed within a case of the device and an antenna with an inverted E shape mounted within a header of the device. The antenna has three branches extending from a main arm: a capacitive branch connecting one end of the main arm to the case； an RF signal feed branch connecting a middle portion of the main arm to the internal RF components of the device via a feedthrough； and an inductive branch connecting the opposing (far) end of the main arm to the case to provide a shunt to ground.
