Multiport automatic calibration device for a multiport test system

An N-port automatic calibration device comprising N-ports, each port adapted to be coupled to a port of a N-port multiport test set, the N-port automatic calibration device comprising:

• a single-pole, N−1 throw switch having a single-pole coupled to a first port of the automatic calibration device and having each throw of N−1 throws coupled to a corresponding port of the automatic calibration device;
• and
• at least one single-pole, double-throw switch, having at least first, second, third, and fourth conditions and having a single pole coupled to a second port of the N-ports of the automatic calibration device, having a first throw coupled to a first load impedance, and having a second throw coupled to a throw of the N−1 throws of the single-pole, N−1 throw switch, said first condition connecting said single pole to said first throw, said second condition connecting said single pole to said second throw, said third condition connecting said single pole to a reference potential within said single-pole, double-throw switch, and said fourth condition connecting said single pole to a high impedance within said single-pole, double-throw switch.