Micromachined frequency-variable impedance tuners using resonant unit cells

This paper presents a new type of micromachined impedance tuners using frequency-variable resonant unit cells. Impedance tuners using resonant unit cells realized by tunable micromachined capacitors showed a wide tuning range equivalent to almost two quadrants of the Smith chart with a high maximum VSWR of 21.2 at Ka-band. Frequency variability is also provided through the use of J-inverters with tunable capacitors. Micromachined tuners are very promising for low-loss tuning of the monolithic circuits as well as accurate noise and power characterization.