Coaxial switches are widely used for signal routing and devices under test (DUTs). In addition, switching matrices are often employed to allow multiple tests to be performed with the same setup. Although switches can still be a pain point for some applications, a fully standalone Universal-Serial-Bus (USB) switch has been proven an economical and time-saving solution for everyday switching needs. In an eight-page application note, “USB Coaxial Switches for RF & Microwave Test and Measurement Applications,” Agilent Technologies delves into features and application examples of a USB coaxial switch.
Although the note focuses specifically on the firm’s U1810B USB switch, it offers guidance on the capabilities of such USB switches in general. In a network analyzer, for example, that switch can be used to measure two DUTs with one connection in either the frequency or time domain. It also can switch between the DUT and the reference unit for calibration or compensation. Clearly, such switches can help to eliminate the time and resources required to change the connection between the DUT and reference unit.
The other application examples include a handheld RF analyzer and spectrum analyzer. For handheld RF analyzers, which perform cable and antenna analysis, the USB switch can allow users to extend the analyzer’s capability. They can perform return-loss, cable-loss, and distance-to-fault (DTF) measurements on two cables. To raise mobility at installation and maintenance sites, the switch can be powered by the USB port or the handheld analyzer.
As it does with the network analyzer, the switch’s use in a spectrum analyzer raises test efficiency because the antenna no longer needs to be disconnected and reconnected. With two antennas connected to the USB switch, the switch can be toggled between them to perform the relevant measurements. These capabilities are enabled by the features of today’s USB coaxial switches, such as a switch topology that help to simplify the test setup without using additional cables. In the case of this switch, a soft front panel also provides an alternative virtual interface, facilitating the ease with which the switches can be controlled. For an increasing number of applications, USB coaxial switches can increase both test setup and programming efficiency for their test systems.
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