Introduction - Broadband Reflectometry for Enhanced Diagnostics and Monitoring Applications - page 3

An optimal trade-off (in terms of low cost, in situ applications, and measurement
accuracy), can be achieved through a TD/FD combined approach. This particular
approach involves standard measurements in one domain and, through a suitable
data-processing, the corresponding information is retrieved in the other domain.
On such bases, the aim of the topic is not only to provide a clear picture of the
most interesting state-of-the-art applications of BMR, but also to give helpful hints
that can allow to fully exploit the potential of BMR. In particular, throughout the
topic several strategies are presented (such as calibration techniques and innovative
processing strategies), all aimed at enhancing measurement accuracy, while still pre-
serving low cost and possibility of practical implementation. Particular emphasis is
given to the possibility of implementing a TD/FD combined approach that, start-
ing from measurements involving low-cost TDR apparata, could provide accurate
results in FD, useful for the intended monitoring purposes. The topic also reports
some significant experimental results that corroborate the proposed methods.
It is important to point out that the explored applications all have strong poten-
tial also for automation, which makes BMR particularly appealing for industrial
applications.
Finally, it is worth mentioning that, although the present topic focuses on mi-
crowave reflectometry, many of the core ideas can be readily extended to applica-
tions of reflectometry that employ different stimulus signals.

1.2 Survey of Typical Applications of BMR

Thanks to the intrinsic versatility and accurate performance, applications of mi-
crowave reflectometry are numerous and cover a wide range of fields. Just to give a
rough idea of the broad spectrum of applications in which BMR can be successfully
adopted as a monitoring tool, here follows an overview (which is far from being ex-
haustive) of some of the most well-established and/or promising application fields.

1.2.1 Electrical Components Characterization: Testing and

Localization of Faults

This application strictly relies on measurements of the electric impedance of the
SUT: in fact, faults along wires or failure of electrical components cause specific
impedance changes that can thus be taken as indicators of malfunction. Several
reflectometry-based approaches have been investigated over the years, a clear de-
scription of such methods can be found in [8]. However, TDR still remains one of
the most advantageous techniques to fulfill this task. In fact, TDR allows to directly
measure the impedance profile of the SUT as a function of the electrical distance.
As a result, also the spatial location of the fault becomes very straightforward.
Locating faults along cables and wirings (in buildings, aircrafts, and so on) is the
foremost application for which TDR was originally developed [7, 21]. Recently, an
approach to locate wire faults using reflectometry without physical contact with the
wire conductor was presented in [38]. In [32], a method based on TDR response and