Dual-frequency rectangular microstrip antenna with an inserted integrated reactive loading

A novel dual-frequency rectangular microstrip antenna with an inserted integrated reactive loading is proposed and experimentally studied. The reactive loading has the structure of a trapezoid microstrip-line section inserted at one of the radiating edges of the patch. By adjusting the flare angle of the trapezoid microstrip-line section, the frequency ratio of the two operating frequencies is tunable in the range of about 1.08–1.17. Also, the two operating frequencies have the same polarization planes and similar broadside radiation characteristics. Details of the antenna design and experimental results are presented and discussed. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 219–221, 2002.