Aeroflex has recently added enhanced VSWR (Return Loss) and Distance to Fault to the tracking generator functionality to the Aeroflex 3550 Digital Radio Test System. By utilizing the sweep of the tracking generator, the 3550 can measure and display the VSWR of an antenna or find the location of one or more faults in a cable. “This extends the current capability of the 3550 tracking generator so that it can now be used in even more ways, giving the field radio technician the tools needed to test the complete system,” said Rob Barden, Director of Product Marketing for Aeroflex Wichita. “This, together with all of the radio test capabilities of the 3550, makes it the ideal choice for testing radio systems, whether on the bench, in a vehicle or at a site.”
The 3550 measures the VSWR of an antenna by transmitting over the frequency range selected by the user and measuring the level of the signal reflected back from the antenna. This is performed with the assistance of a return loss bridge that is connected between two ports of the 3550. The user can select the frequency range and the units to display the reflected signal level, either in dB (return loss) or VSWR. This measurement is an important indication of the performance of the antenna.
The existence and location of one or more faults in a cable can also be determined with the 3550 tracking generator. This sweep, with the assistance of a resistive power divider, combines the signal transmitted by the 3550 with the reflected signal, and then through special signal processing, produces a plot that shows the precise location of any cable faults. This plot not only helps determine the location of the fault, but also the severity. A cable fault determination is critical when trying to determine where the problem lies, in the radio or the antenna/cable system.
