| 摘要 |
PURPOSE:To avoid the presence of a heater such as a resistor plate in a waveguide by combining circular phase shifters so as to incorporate a variable attenuation function and a variable phase shift function thereby attaining miniaturization and light weight. CONSTITUTION:A rectangular circular converting waveguide 1, a circular 90 deg. phase shifter 2 having a phase shift plane rotated by pi/4 radian from a perpen dicular axis, a circular 180 deg. phase shifter 3 whose shift plane is rotated freely, a circular 90 deg. phase shifter 4 having phase shift plane rotated by rho/4 radian in opposite direction to said circular 90 deg. phase shifter 2 from the same circular 90 deg. phase shifter as the phase shifter 2 or the perpendicular axis, the same phase shifter 5 as the phase shifter 2 and an orthogonal polarized branching device 6 whose one end is terminated by resistive terminator 7 are connected in cascade in said order. Thus, both the attenuation and the phase shift amount have wide continuous variable range and the accuracy is kept high. Moreover, a radio wave absorbing body is not provided in the waveguide and an externally mounted resistive terminator absorbs the radio wave to be attenuated, then no heat is generated in the waveguide. |
