Measurement of antenna radiation efficiency using improved Wheeler cap algorithm

antennas;antenna radiation efficiency

Wilken-Resman, Elias ; Bernhard ; Jennifer T.

关键词: antennas;    antenna radiation efficiency;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/90975/WILKEN-RESMAN-THESIS-2016.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Radiation efficiency measurement can inform the wireless design process by determining the total fraction of accepted power radiated by an antenna. The popular Wheeler cap method can be used to quickly and accurately determine the radiation efficiency of small antennas. However, due to cavity resonant modes and the use of a simplistic equivalent circuit model, the conventional Wheeler cap method yields poor results for electrically larger structures. When efficiency estimates can be obtained, they are often valid only over a narrow frequency band. Higher-order equivalent circuit models may be employed in a modified Wheeler cap algorithm to generate improved radiation efficiency measurements. Guided by advances in broadband modeling of antennas, we demonstrate a new Wheeler cap technique that makes use of parallel admittance subcircuits. We then illustrate the use of this technique to provide improved efficiency estimates at the operating frequencies of electrically larger structures.