Planar printed loop antenna with less no‐ground space for hepta‐band wireless wide area network/long‐term evolution mobile handset

Abstract

A planar printed loop antenna with hepta operating bands, which covers the GSM850/900/DCS1800/PCS1900/UMTS2100/LTE2300/2500 bands for mobile handset application, is proposed. It occupies a no-ground space of only 8 × 60 mm2 and wideband operation can be achieved by meandering or folding loop line and using matching circuits. The low frequency bands of GSM850/900 operation are achieved by the loop half-wavelength mode and matching chip capacitor, which generates a dual-resonance mode at 780 and 915 MHz. At around high frequency ranges, a one-wavelength resonant mode of the entire loop at 1.66 GHz, and high-order resonant modes of the left or the right side coupling loop are generated to cover the residual frequency bands. In addition, the proposed antenna is easily printed on dielectric surfaces of a low cost FR4 substrate, which makes it suitable for practical mobile applications. The proposed antenna is successfully simulated, fabricated, and measured comparing to simulated results to validate the design.