TY - GEN AU - Freeman, J J C2 - , National Institute of Standards and Technology, Gaithersburg, MD DA - 1947-01-01 05:01:00 DO - https://doi.org/10.6028/NBS.CRPL.9-2 LA - en PB - , National Institute of Standards and Technology, Gaithersburg, MD PY - 1947 TI - Theory and design of a waveguide below cut-off attenuator: ER -