Metamaterial-inspired dual-band frequency-reconfigurable antenna with pattern diversity

Abstract

Multi-functional antennas are very important in modern wireless communication systems. A novel dual-band frequency-reconfigurable antenna with pattern diversity is designed. The antenna consists of a composite right/left-handed transmission line inspired structure, which works at the zeroth-order mode (0) around 2.5 GHz and at the first-order mode (1) around 3.5 GHz. The 0 mode results in an omnidirectional pattern and the 1 mode results in a broadside pattern. By adding varactors to continuously reconfigure the structure, the antenna is able to tune its lower resonant frequency from 2.36 to 2.60 GHz, which fully covers the 2.4–2.5 GHz ISM band, and tune its higher resonant frequency from 3.34 to 3.73 GHz, which fully covers the 3.4–3.7 GHz WiMAX band. Simulations and experiments match well, proving the validity of this new concept.