A Quadband Antenna With Reconfigurable Feedings

A compact inverted-F antenna (IFA) with switchable feeds is proposed in this letter. The antenna occupies a relatively small volume of 50$\,\times\,$7$\,\times\,$7 mm$^{3}$. Two pin diodes are used to switch the antenna between two different working states. The antenna can provide the required bands of GSM850 (824894 MHz), GSM900 (890960 MHz), DCS (17101880 MHz), and PCS (18501990 MHz) with ${\rm S}11 < {-}10$ dB. Measurements including return loss, radiation patterns, and gain are presented to verify the proposed design of antenna.