Resonant frequencies and dual-frequency operation of a bow-tie microstrip antenna

A closed-form formula for dual resonant frequencies of a bow-tie microstrip antenna is derived by means of the variation method, and its dual-frequency operation is verified theoretically and experimentally. For its theoretical analysis, the method of moment (MoM) program is established. The calculated results and the measured ones are in good agreement, showing the validity of this numerical analysis and design program. The results also show that operating at low frequency of the test dual frequency bow-tie antenna, its size is much smaller than a conventional rectangular patch antenna.