Tunable impedance transformer using multiconductor coupled lines

A new tunable impedance transformer is presented using multiconductor coupled line of quarter-wave length.The switches are connected at the ends of the conductor lines in the coupled line, and they are used to adjust the equivalent capacitance of the line. It leads to the variation of characteristic impedance of the quarter-wave long line, resulting in the tunable impedance transformer. The measurement around 1.9 GHz shows that the characteristic impedance of the transformer using five-conductor coupled line can be adjusted from 29.5 to 56.5.