Dual-Band and Tri-Band Parasitic Dipole Antennas for Wearable Applications

Dual-band and triple-band(Tri-band) T-shaped dipole antennas with two couples of parasitic dipoles are proposed. Two or three resonances are realized by T-shaped printed dipoles and parasitic dipoles, respectively. The frequency of resonance depends on the width and length of parasitic dipoles. The proposed structure can achieve multiband operation. Both of the middle and upper operating frequencies can be easily controlled independently. Simulation results show that the maximum realized gains for tri-band antenna are 2.69 dBi, 1.65 dBi and 2.76 dBi at the resonant frequencies of 2.5 GHz, 4.6 GHz and 5.6 GHz, and the maximum realized gains for dual-band antenna are 3.11 dBi and 2.78 dBi at the operating frequencies of 2.5 GHz and 5.6 GHz. The proposed antennas are suitable for wearable applications.