Fault detection method
A device for testing faults and non-conformities in a waveguide, in a radio transmitting system comprising a transmitter connected to an antenna by a waveguide, a coaxial cable or a coaxial line. The device is arranged for injecting a signal in the waveguide and for receiving a backscattered signal, characterizing a nonconformity or a fault. The injected signal may be a digital UWB signal.
1 . A device for testing faults and non-conformities in a waveguide connecting a transmitter to a radio antenna in a transmitting or transmitting/receiving radio system, comprising:
a radar transmitter for generating a radar signal;
a coupler for receiving the radar signal from the radar transmitter and injecting the radar signal in the waveguide, superposed to a service signal transmitted by means of the waveguide;
a receiver for receiving a backscattered signal; and
a detection apparatus for determining presence and position of discontinuities in the waveguide based on the backscattered signal.
2 . The device of claim 1 , wherein the injected radar signal is a modulated BPSK signal.
3 . The device of claim 2 , the transmitter being configured to generate the modulated BPSK signal by multiplying and/or modulating a given binary sequence with a carrier frequency in the transmitter.
4 . The device of claim 3 , wherein the receiver is configured to generate of a base-band backscattered signal from said backscattered signal.
5 . The device of claim 3 , the receiver being further configured to correlate a copy of said given binary sequence with the received backscattered signal and to provide a Time of Flight of the received backscattered signal.
6 . The device of claim 1 , wherein the radar signal is an ultra-wide-band radar signal having an arithmetic mean carrier frequency and a bandwidth exceeding the lesser of 500 MHz or 20% of the arithmetic mean carrier frequency.
7 . The device of claim 3 , wherein said given binary sequence is based on a forward error correction code.
8 . The device of claim 1 , the service signal being a radio/TV broadcast signal in the UHF range or in the FM range.
9 . The device of claim 8 , the radar signal comprising short pulses of less than 10 ns duration.