A compact triple-band printed dipole antenna using C-shaped resonators with stable radiation for GSM/ISM/WLAN applications

A compact printed dipole antenna using an integrated balun is introduced in this work, which is achieved three frequency bands by using C-shaped resonators. The total dimension of the proposed antenna is 42 x 72 mm(2), and it covers the frequency bands of 1.62-1.88, 2.36-2.81, and 5.15-6.16 GHz with S-11 < -10 dB. Furthermore, the measured peak gains of the antenna in three frequency bands are equal to 8.52, 9.46, and 6.81 dB, respectively. Dipole antennas with integrated baluns have a main frequency band based on the length of the dipole arms. Nevertheless, in the presented design, two additional frequency bands have been created for the antenna, by producing suitable magnetic couplings between the C-shaped resonators and the Gamma-shaped feed line innovatively, which has a better radiation behavior, unlike traditional triple-band antennas. An equivalent circuit of the introduced antenna has been investigated and afterward, the optimized antenna has been fabricated and tested.