• The start...kinda

    Shankar Ramharack • 12/30/2021 at 14:45 • 0 comments

    Ultra Wide Band (UWB) Technology

    Ultra-wideband is a technology for transmitting information across a wide bandwidth (>500 MHz). It has applications in communications, positioning systems, medical imaging, and radar systems. Recently I was tasked with developing a low-cost time-domain reflectometer (TDR) for application on low voltage and medium voltage transmission lines for a range of 2-5km. To achieve a high spatial resolution in the gigahertz range, a low rise time excitation signal was needed. Furthermore, the excitation signal was specified to have an amplitude of 10-60V like most commercial systems. The waveform of choice was a step wave, however, I could not find any commercially available off-the-shelf (COTS) excitation sources for the broadband bandwidth I required and discovered after 3 months of research that a 10-50V ps rise time source did not exist or rather could not be found by me. In this project, I wanna go a bit above the 60V threshold and go up to 200V. The highest TDR I saw was 160V. Anything beyond this, ARM, or some other HV Impulse method should be considered for fault location.

    In case you're interested, more on the bandwidth requirements for TDR can be found here.

    After an extensive review of the literature, I gathered that the most common methods of UWB pulse generation(UWBPG) are:

    Although I intend to build these UWBPGs for the 10-200V application, I do not currently have access to a UWB oscilloscope capable of verifying my results. I intend to develop a GHz band oscilloscope similar to that of Ted Yapo and luxodes.