TWIN LOOP ANTENNA COUNTERMEASURING GHOST

摘要

PURPOSE: To reduce a reflecting wave from a back side of an antenna and to reduce a ground reflecting wave. ;CONSTITUTION: A phase difference of 90° is given to induced currents between two sets of 1λ twin loop antennas 1, 2 by arranging the two sets of 1λ twin loop antennas 1, 2 in resonance with a reception frequency at an interval of 1/4λ. An induced current I_d1 resulting from a wave received directly by the twin loop antenna 1 and an induced current I_r1-90° resulting from the reception of a reflecting wave are inputted to an input terminal #1 of a 3dB coupler, and an induced current I_d2-90° resulting from a wave received directly by the twin loop antenna 2 and an induced current I_r2 resulting from the reception of a reflecting wave are inputted to an input terminal #2 of the 3dB coupler, then an induced current I_r1 by the reception of a reflecting wave appears at an output terminal #3 and only an induced current I_d1 by the reception of a direct wave appears at an output terminal #4.;COPYRIGHT: (C)1994,JPO&Japio