The Keysight 85131D is a 53 cm long, semi-rigid RF cable set specially developed for precise high-frequency measurements in the DC to 26.5 GHz range. It consists of a 3.5 mm plug (male) and a PSC 3.5 mm plug (female), whereby the PSC plug is designed to be particularly robust for connection to network analyzers. With a return loss of at least 16 dB and an insertion loss of 0.3 × √f + 0.2 dB (f in GHz), the cable set offers excellent electrical properties. The phase stability is less than 0.06 dB and the phase deviation is 0.16 × f + 0.5°, measured at a 90° bending radius of 7.6 cm. This cable set is ideal for applications that require maximum precision and reliability, especially in conjunction with Keysight network analyzers.