Half‐wavelength loop strip capacitively fed by a printed monopole for penta‐band mobile phone antenna

In this study, a novel internal penta‐band antenna formed by a half‐wavelength loop strip capacitively fed by a printed monopole for mobile phone application is proposed. The antenna is configured such that, inside the antenna region, possible electronic elements, such as the speaker or the like, can be embedded to achieve a compact integration of the antenna inside the mobile phone; moreover, the antenna performances can be very slightly affected by the integrated element. The antenna can further generate two wide resonant modes at about 900 and 1900 MHz for GSM850/900 and DCS/PCS/UMTS operation, respectively. In addition, the two resonant modes can generally be controlled separately, with the lower one controlled by the loop strip operated as a 0.5‐wavelength structure and the upper one controlled by the printed monopole operated as a 0.25‐wavelength structure. Detailed design considerations of the proposed antenna are presented.