Detecting microwave and millimeter wave/THz signals using AC driven glow discharge detectors

The use of neon indictor lamp glow discharge detectors (GDDs) has a relatively great potential for a number of microwave and THz detecting and imaging applications. This is so because of their many advantages which include but not limited to; low cost, fast response time and wider dynamic range. In this thesis, we experimentally examine the performance of an AC driven GDD while detecting a THz signal of 60GHz modulated at 170kHz as well as a microwave signal of 10.5GHz. It is observed that driving the GDD with alternating voltage curbs the problem of GDD burn-out that's associated with DC driven GDDs. Nonetheless it is also experimentally proved that the GDD responsivity of a DC driven GDD diminishes with time whereby within 10 minutes the responsivity drops from 100mV to 42mV. Furthermore, microwave interaction with an AC driven GDD is also examined in that the effect of the distance between signal source of 10.5GHz and the GDD on the signal peak to peak voltage (Vpp) for peculiar modulation frequencies is analyzed. The most efficient modulation frequency is found to be 200kHz followed by 250kHz. Key words: Terahertz radiation, Microwave, Glow Discharge, Neon indictor lamps, Detection, Plasma