Adaura Technologies AD-USB4A series of digital programmable attenuators operate from 0.5 to 6 GHz. The attenuators have a range from 0 to 63 dB with 1 dB increments. Four independent channels can be controlled and powered via one single USB port. An easy to use GUI provides fixed attenuations as well as flexible ramp functions. Custom automation is easily accomplished via simple serial port commands on any Windows or Linux based PC. It is ideal for cellular, microwave radio, and WiFi MIMO engineering development and manufacturing test. It is available in a compact module with SMA female ports.