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I'm only familiar with scopes, DMMs and a little spectrum analyzers.

But I couldn't understand what an "RF switch" is used for particularly in a characterization lab.

Can you give an example of its use and function and describe in layman terms?

GNZ
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  • Can you define what a characterization lab is - you can also use layman terms if it helps. – Andy aka May 21 '20 at 13:45
  • I mean the lab where they measure characteristics of systems and components. Like for an ADC characterization can be figuring out its DNL INL ect. or for an oscillator stability. – GNZ May 21 '20 at 13:47
  • In what context did you come across the term - it can mean many things and context would help. – Andy aka May 21 '20 at 13:50
  • Here is an example https://www.pickeringtest.com/en-dk/products/pci/switch-cards/rf-cards Im compeletly blank about its meaning. But it seems they are used in advanced instrumentation PCI equipment (?). – GNZ May 21 '20 at 13:53
  • The Pickering circuit boards are plug in PCI cards that have terminals that can be opened and closed under command. These terminals are suitable for switching RF circuit currents and voltages. – Andy aka May 21 '20 at 13:57
  • Use them whenever hiring a person to connect and disconnect cables over and over again would be more expensive. – The Photon May 21 '20 at 14:43

1 Answers1

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One place RF switches are used is to switch, or multiplex multiple RF sources into a single piece of test equipment.

Here's an example. Most modern day antenna systems have multiple RF outputs that may include SUM, Delta-Az, and Delta-El channels. All of these need to be characterized for phase and amplitude response as function of frequency, scan angle, temperature, etc. These measurements are done using complicated/expensive test gear like spectrum analyzers and vector network analyzers (VNAs). It is usually cost prohibited to provide one set of this test gear for each of the 3 channels mentioned earlier. So it is very common to have a single set of test gear and an RF or set of RF switches that switch the desired RF channel into the test set to make the needed measurements for each channel.

SteveSh
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  • Thanks for the answer really I was looking for. One last question about it. You mentioned RF switch is used for to switch channels to view on limited number of analyzers. But why not any other switch but RF switch is used? What is the advantage? Ate they less prone to debouncing? Why not a multiplexer but RF switch? – GNZ May 21 '20 at 15:38
  • RF switches are specially made to minimize disturbances to the RF signal you're trying to measure. Even with that, in many cases you have to characterize (measure) the RF switch and back that out of the measurement of the RF channel. For instance, if you're trying to measure the loss through a path, and the switch has a loss of 3 dB, you need to take the switch loss into account. – SteveSh May 21 '20 at 15:44