Data traffic is increasing rapidly, especially on wireless channels, pushing the carrier frequency to the X, K, and millimeter-wave (MMW) bands. This requires development of new technologies and communication components operating at those bands. The detectors and receivers for those bands are very expensive, have high sensitivity to electrostatic discharge, and can be damaged by high incident power. An ultra-wideband and inexpensive glow discharge detector (GDD) is presented here. The GDD was found to be an excellent microwave and MMW radiation detector. The detection mechanism presented here is based on upconversion of microwave and MMW radiation to visual light. The experimental results demonstrate ultra-wideband detection at X and at MMW bands. These results present a proof of concept for the ability of our system to be used as a detector in wireless communication for the 5th generation.