Experimental Study on Return Loss of Exponential Tapered Line Type Conical Monopole Antenna
Kiyoshi Furuya, Ken Kawamata, Shigeki Minegishi · IEEJ Transactions on Fundamentals and Materials · 2015
Exponential tapered line type conical monopole antenna is proposed as a radiator of electromagnetic wave due to electrostatic discharge (ESD). The electromagnetic wave radiated by discharge such as ESD is broadband and influenced by lead lines connected to discharge electrodes. Therefore, the broadband antenna, which can lay on the electrodes to the antenna input and withstand the high voltage, is required instead of lead lines. The proposed antenna is the conical monopole antenna having an exponential tapered line structure. The characteristic impedance of the antenna changes from 50Ω to the free space impedance according to exponential function. The return loss and input impedance of the conical monopole antenna were measured by a network analyzer in the frequency range from 300kHz to 9GHz. As a result of experiment, the return loss was less then -20dB and the input impedance was 50Ω in frequency range from 1.6GHz to 9GHz. The results of the experiment are compared with the linear tapered line type monopole antenna that the characteristic impedance changes from 50Ω to the free space impedance linearly. The return loss of the conical monopole antenna was lower than that of the linear tapered line type monopole antenna.