Impedance characteristics of trapezoidal planar monopole antennas

Trapezoidal planar monopole antennas are presented and investigated experimentally, which typically have an impedance bandwidth of >80%. To accurately evaluate the frequency corresponding to the lower edge of the impedance bandwidth, a modified formula is proposed. © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 27: 120–122, 2000.