Abstract:
This paper proposes a tri-band rectangular monopole antenna surrounded by rectangular
ring with symmetrical perturbation inverted L-shape strips for wireless communications.
The antenna structure is simple, compact and lightweight. It is printed on FR4 substrate
of dimensions of 50 × 50 mm. with the relative permittivity of 4.3, high of 1.6 mm and
fed by coplanar waveguide with 50-ohm impedance. This presented antenna consists of a
monopole rectangular radiating patch, a pair of inverted L-shape strip for improving the
impedance matching, and a rectangular ring to control its radiation to be bidirectional pattern.
In the processes, an electromagnetic microwave simulation tool is employed to investigate
optimum parameters. It is found that both simulated and measured results are in good agreement.
This antenna provides S11 < -10 dB covered 1.50 - 2.22, 2.77 - 3.81, and 4.45 - 6.37 GHz with
maximum gains of 1.52, 3.44, and 2.72 dBi, respectively.