RF delay lines with variable composition fluidic dielectric

摘要

Method and apparatus for producing a variable delay for an RF signal. The method can include the step of propagating the RF signal along an RF transmission line, coupling a fluidic dielectric to the RF transmission line, and dynamically changing a composition of the fluidic dielectric to selectively vary its permittivity in response to a time delay control signal. The method can also include the step of dynamically changing a composition of the fluidic dielectric to vary its permeability. The permittivity and the permeability can be varied concurrently in response to the time delay control signal. In a preferred embodiment the method can include selectively varying the permeability concurrently with the permittivity to maintain a characteristic impedance of the transmission line approximately constant.