Small multi-band microstrip antenna for wireless applications

A simple microstrip line fed antenna with thin substrate is proposed in this letter for multi-band wireless applications. The multi-band characteristic was achieved by overlapping an annular slot antenna with two concentric fan shaped patches. The antenna demonstrates three wide impedance bandwidths (VSWR ≤ 2) of 36.3, 63.4 and 25.5% with stable polarization and radiation characteristics.