The ST18/SMAM/SMAM/48IN is a microwave test assembly cable designed for precision RF and microwave measurements up to 18 GHz. It features two SMA straight-plug male connectors on both ends with 50 Ohm impedance, a length of 1219 mm (48 inches) measured reference-to-reference, and is constructed using SUCOTEST_18 cable. The assembly delivers excellent insertion and return loss characteristics with a minimum return loss of 19 dB, maximum VSWR of 1.253, and maximum insertion loss of 1.99 dB, along with unique loss stability across its operating range. It supports CW power of 131 W at 18 GHz, operates from -55 °C to +105 °C, and is ideal for high-frequency test and measurement applications in laboratory and field environments where signal integrity and repeatability are critical.