Internal compact small-size printed compound monopole antenna for mobile phone

In this paper, we propose a small-size printed compound monopole antenna for application in mobile phones as an internal antenna. The antenna comprises an outer strip, an inner strip, and a common section. The antenna structure is simple and easy to manufacture. It occupies a compact area of 25 × 20 mm 2 only, yet generating two resonant modes to form two wide bands. Two operating frequency bands of the antenna covering the GSM/DCS/PCS/UMTS are met with 6 dB return loss specification, so it is well suitable to be used for mobile phone application.