The 3658 series AutoCal® modules are automatic calibrators that provide fast, repeatable, and high-quality coaxial calibrations up to 40 GHz. These modules contain precisely characterized calibration standards that aid in the removal of normal systematic errors when using vector network analyzers (VNAs). AutoCal® is available in three models: 0.04 GHz to 18 GHz, with N(m) to N(f) connectors, and 0.04 GHz to 20 GHz, with K(m) to K(f) connectors, and 0.04 GHz to 40 GHz, with K(m) to K(f) connectors. AutoCal® modules come with a data file characterizing each standard in the calibrator module. Each module is guaranteed to perform to its specifications for 6 months without re-characterization. Following this period, re-characterization can be performed by the customer, or by sending the module to the nearest service center. Test port cable converter sets aid the user in calibrating a VNA for testing non-insertable devices and devices with SMA or 3.5 mm connectors. Test port converter sets are available for K Connector® , SMA, and 3.5 mm connectors. Adapter removal calibration is required for N type non-insertable device testing. AutoCal® has a direct serial interface to the 37000 and MS464x series of Anritsu vector network analyzers. The control software is built-in to the VNA.