The 58A50 is a 2 to 18 GHz VSWR bridge with a directivity of 35 dB. Unlike traditional bridges that have an internal termination, the 58A50 uses an external reference termination. This permits use of a reference offset termination and a precision airline to achieve accurate measurements to 50 dB using a ripple extraction method. This achieves an effective directivity of 57 dB. The reference and test port connectors are 7 mm. The rf input and output connectors are type N-female.