The ACM2509 from Copper Mountain Technologies is an Automatic Calibration Module that operates from 20 kHz to 9 GHz and can be used with all CMT vector network analyzers. It is a fully automatic USB-controlled and powered electronic calibration module which expedites the calibration process. To perform full two-port calibration, each end of the ACM needs to be connected to the analyzer once, as opposed to seven connections with passive calibration kits. The ACM also contains a factory characterized 20 dB in-line attenuator which acts as a simulated device under test (DUT). The VNA calibration coefficients are calculated using the measured S-parameters of the ACM impedance states and stored in the ACM memory. It is available in a module that measures 115 x 40 x 25 mm with N-Type (F) and 3.5 mm (F) connector options.