Antenna Delay Calibration of UWB Nodes

Impulse-radio ultra-wideband (IR-UWB) networks are gaining wide acceptance in short-to-medium range wireless sensing and positioning applications that require high accuracy. It is achieved generally via signal message exchange between ultra-wideband (UWB) transceiver nodes, where the signal propagating through their analog circuitry suffers transmitting and receiving antenna delays. Such delays, unless measured and properly corrected for, may induce an error in range estimation between UWB nodes and eventually affect the accuracy of real-time location systems (RTLSs) based on the IR-UWB. This paper presents a system to measure the antenna delays of UWB nodes. It provides comprehensive mathematical modeling, design, and implementation of the proposed antenna delay measurement system. Experimental evaluation in a line-of-sight (LOS) environment shows its effectiveness for maintaining the accuracy of the range measurement between UWB nodes by taking into consideration the antenna delays measured by the proposed system.