Calibration system and calibration method for a vector network analyzer

A calibration method for a vector network analyzer, VNA, having a plurality of N ports, wherein N represents the number of ports of the VNA, the calibration method comprising the steps of:

• providing a calibration system comprising:
• a distribution unit having a plurality of D ports, wherein D represents the number of ports of the distribution unit, and D≤N;
• and
• a plurality of D calibration units, respectively comprising a calibration circuit having first, second and third ports, and an isolation circuit having first, second and third ports;
• connecting, for a respective calibration unit:
• the first port of the calibration circuit to a respective port of the VNA,
• the second port of the calibration circuit to the first port of the isolation circuit,
• the third port of the calibration circuit to a first matched load;
• the second port of the isolation circuit to a respective port of the distribution unit, and
• the third port of the isolation circuit to a second matched load;
• controlling the respective calibration unit to subsequently provide at least three different one-port calibration standards such as open, short and match to the respective port of the VNA;
• and
• conducting a measurement for the respective calibration standard provided to the respective port of the VNA, wherein the measurements for the respective calibration standard are conducted sequentially.