@misc{1181371,
  author = {Arthur D Yaghjian},
  title = {An approximate expression for the principal beamwidths of directive antennas in terms of aperture fields:},
  year = {1981},
  month = {1981-01-01 05:01:00},
  publisher = {, National Institute of Standards and Technology, Gaithersburg, MD},
  doi = {https://doi.org/10.6028/NBS.IR.81-1644},
  language = {en},
}