Recent Progress in Fault Diagnosis of Phased Antenna Arrays Using Excitation Engineering

We review recent results in the area of fault diagnosis of phased antenna arrays. These results have distinguishing features that set them apart from related work, namely the use of a single, fixed measurement location, and the optimization of the excitations of the antenna elements of the array. We start with the relatively simple scenario of ignoring inter-element mutual coupling, and show how the element excitations can be optimized to reduce the mutual coherence of the sensing matrix. This leads to successful fault diagnosis with a reduced number of measurements. We then generalize this idea in two directions. In the first, we explore applications in the frequency domain by demonstrating online fault diagnosis in multi-carrier precoding systems. Here, a portion of the spectrum is used for fault diagnosis while the remaining continues to be used for wireless communication. In the second, we upgrade our technique for the case when inter-element mutual coupling is significant. By using two popular models that incorporate mutual coupling effects, we demonstrate efficient fault diagnosis also in this scenario. We expect these techniques to greatly simplify the task of fault diagnosis in modern wireless communication systems.