Modal Resonant Frequencies and Radiation Quality Factors of Microstrip Antennas

[摘要] The chosen rectangular and fractal microstrip patch antennas above an infinite ground plane are analyzed by the theory of characteristic modes. The resonant frequencies and radiationQare evaluated. A novel method by Vandenbosch for rigorous evaluation of the radiationQis employed for modal currents on a Rao-Wilton-Glisson (RWG) mesh. It is found that the resonant frequency of a rectangular patch antenna with a dominant mode presents quite complicated behaviour including having a minimum at a specific height. Similarly, as predicted from the simple wire model, the radiationQexhibits a minimum too. It is observed that the presence of out-of-phase currents flowing along the patch antenna leads to a significant increase of theQfactor.

[学科分类] 电子、光学、磁材料