Patent ID: 6075424
Filing Date: 2000-06-13
Classification: H01P

Abstract:
An article for imparting a phase shift to a signal traveling through a transmission line, the transmission line having at least one active line and at least one ground, wherein the one line and the one ground are disposed in spaced and parallel relation to one another, the article comprising:a phase-shifting slab movable in the space between the active line and ground, the phase-shifting slab having:a phase-shifting member having a regular variation in dielectric constant, said phase-shifting member operable to provide a regular change in an effective dielectric constant of the transmission line as the phase-shifting member is moved through said space; anda first impedance-matching member operable to reduce impedance mismatch that occurs as the signal travels from a first region of the transmission line having a first impedance to a second region of the transmission line having a second impedance, wherein said first impedance-matching member is physically configured to reduce impedance mismatch across a full range of movement of said phase-shifting slab in said space;wherein, in the first region, the phase-shifting slab is not present between the active line and the ground, and, in the second region, at least a portion of the phase-shifting slab is disposed between the active line and the ground.