SUPPRESSING DEVICE OF UNDESIRED MODE

摘要

PURPOSE:To avoid occurrence of the H21 mode, by distributing the probes or loops at the position where the electric field or magnetic field of H21 mode becomes maximum and then giving connections among the opposite probes or loops to transmit selectively the frequency component of the H21 mode in opposite phase. CONSTITUTION:The loops 22, 23, 24 and 25 are attached on the short-circuit face 21 so as to cut the magnetic field H. Then loops 22 and 23 are distributed on the diameter B-B' which forms 45 with the rectangular waveguide 12; and the loops 24 and 25 are provided on the diameter C-C' which is orthogonal to the diameter B-B', respectively. Furthermore an external line 26 is provided to secure a connection between the loops 22 and 23. The current inducted by the loop 22 and that inducted by the loop 23 have the opposite phase to each other to negate the magnetic field of the loop in the opposite side mutually. An external line is also provided between the loops 24 and 25 to perform the similar negation of the magnetic field that cuts the loop of the opposite side to each other.