Multi-band low frequency impedance tuner

A calibration method for electro-mechanical impedance tuner,

• whereby said tuner is operationally connected to a pre-calibrated vector network analyzer using RF cables and,
• whereby said tuner comprises an input port and an output port and a cascade of three or more shunt capacitance blocks;
• said capacitance blocks comprising variable capacitors of which one terminal is grounded and the other floating, and
• said capacitance blocks being inter-connected using exchangeable lengths of low loss coaxial cable, exchanged by switching RF SPDT switches,
• whereby said cable sections inter-connect the floating terminals of the cascade of said capacitors starting at the tuner input port and terminating at the output port,
• said capacitances being mechanically set to various positions using stepper motors,
• the total assembly being digitally remotely controlled by a computer and control electronics, which runs software allowing to control the stepper motors, and communicate with said network analyzer in order to collect s-parameter data of said tuner at the various capacitor positions.